A New Bloody Pulp Selection of Myrobalan (Prunus cerasifera L.): Pomological Traits, Chemical Composition, and Nutraceutical Properties

Abstract

A new accession of myrobalan (Prunus cerasifera L.) from Sicily (Italy) was studied for the first time for its chemical and nutraceutical properties. A description of the main morphological and pomological traits was created as a tool for characterization for consumers. For this purpose, three different extracts of fresh myrobalan fruits were subjected to different analyses, including the evaluation of total phenol (TPC), flavonoid (TFC), and anthocyanin (TAC) contents. The extracts exhibited a TPC in the range 34.52–97.63 mg gallic acid equivalent (GAE)/100 g fresh weight (FW), a TFC of 0.23–0.96 mg quercetin equivalent (QE)/100 g FW, and a TAC of 20.24–55.33 cyanidine-3-O-glucoside/100 g FW. LC-HRMS analysis evidenced that the compounds mainly belong to the flavonols, flavan-3-ols, proanthocyanidins, anthocyanins, hydroxycinnamic acid derivatives, and organic acids classes. A multitarget approach was used to assess the antioxidant properties by using FRAP, ABTS, DPPH, and β-carotene bleaching tests. Moreover, the myrobalan fruit extracts were tested as inhibitors of the key enzymes related to obesity and metabolic syndrome (α-glucosidase, α-amylase, and lipase). All extracts exhibited an ABTS radical scavenging activity that was higher than the positive control BHT (IC₅₀ value in the range 1.19–2.97 μg/mL). Moreover, all extracts showed iron-reducing activity, with a potency similar to that of BHT (53.01–64.90 vs 3.26 μM Fe(II)/g). The PF extract exhibited a promising lipase inhibitory effect (IC₅₀ value of 29.61 μg/mL).

1. Introduction

Among fresh fruit species, plums (genus Prunus) play a non-determinant role in terms of production and cultivated surfaces, yet it is traditionally found in many areas characterized by temperate climates. It is usually considered a minor stone fruit together with apricot mostly because it is compared to peach and nectarines, which accounts for wider diffusion and growing areas [1]. The species has a complex botanical classification because several species are traced back to the name plum, and its hybridizations, natural and/or induced, are widespread [2]. Domestic or European plums (Prunus domestica L.) are generally used for processing into dried plums, while Japanese plums (Prunus salicina Lindl.) are almost exclusively used for fresh consumption. The names of the two species highlight the links between the origin and geographical distribution, with the former being more closely associated with the old continent and the latter with the Asian continent. However, these are genetically distant species characterized by different ploidy levels.

Myrobalan (Prunus cerasifera L.) is a diploid, widespread species in the Mediterranean. This species is credited with the origin of European plums via hybridization with the tetraploid P. Spinosa, and for this reason, myrobalan is considered genetically close to P. domestica, although with different ploidy [1]. It is widely used as rootstock for both plum and apricot trees, more rarely for peach [3,4] thanks mainly to its ability to produce adventitious roots that facilitate its propagation [5,6].

In many traditional fruit-growing areas, where intensive agriculture has not taken over, there are several edible fruiting myrobalan accessions, often small (hence referred to as cherry-plum), selected by farmers and passed down because of the consumption related to the gastronomic traditions of indigenous peoples [7]. For this reason, many studies have focused on characterizing the accessions that are locally grown and highly valued by consumers, often for the taste qualities of the fruits as well as their early ripening time [8]. This approach is very often based on the analysis of morphological data through the adoption of specific descriptor lists studied and approved on a global scale [9]. The morphological traits of flowers, leaves, fruits, and seeds are studied, as well as wood, crown, bud characteristics, tree habit, and phenotypic behavior by the age of maturity and flowering. More recently, it has been proposed to combine these observations with a molecular-scale evaluation model, which, however, becomes effective only when morphological analysis fails to separate different accessions and, in any case, only in the presence of an adequate bank of genetic information [10]. Over the past decade, on an international scale, many research centers have initiated several programs for biodiversity conservation and characterization in accordance with the provisions of the International Treaty on Plant Genetic Resources for Agriculture and Food [11]. This important agreement has given all participating countries a responsibility in the conservation of indigenous genetic resources through the development of national plans in which the main objective is to enable a description of biodiversity with comparable and recognized patterns. Many innovative approaches have been developed for preserving plum biodiversity from the risk of erosion and/or extinction [12]. It is well known that the myrobalan fruits are usually rich in fibers and antioxidants, evidencing an important role in terms of nutritional source [13]; however, cherry plums are not so widely diffused due to the low resistance of the fruit in the postharvest management. Given that germplasm conservation is a substantial contribution to preserving knowledge about all crops, the identification of new resources and their characterization is an indispensable tool for achieving sustainable development targets by reducing the risk of genetic erosion. Indigenous genetic diversity is now recognized as a tool for resilience, mitigating the climate crisis due to increased adaptation with less consumption of natural resources, especially soil and water. Genetic diversity can conserve those genes that are potentially useful in strengthening resistance to pathogens or adaptability to stresses [14]. On a global scale, this type of work is also of strategic importance with a view to achieving the Agenda 2030 goals [15]. The conservation of biodiversity of agricultural interest and its morphological and functional characterization is central to SDGs 1, 2, 3, 12, and 14, with the general convergence of all targets toward SDG 13 being related to urgent action on climate change mitigation and adaptation, which, in some ways, underlies all the goals [16].

The attention of consumers toward an increasingly healthy diet has led to an increase in the consumption of fruits, with reference to red fruits not only for their nutritional value but also for their characteristic taste and their well-known health properties [17]. In fact, these fruits, in addition to vitamins and minerals, are rich in compounds with several health properties, mainly phenolic acids such as p-coumaric acid, vanillic acid β-glucoside, protocatechuic acid, and caffeic acid, and flavonoids such as catechin, epicatechin, quercetin and cyanidin-3-O-glucoside [18,19,20].

Metabolic syndrome (MetS) is a complex disorder that is often associated with insulin resistance, high cholesterol and triglycerides levels, and abdominal obesity [21]. The role of oxidative stress in its pathogenesis was proved [22,23]. Găman et al. [24] evidenced that in the pancreatic β cells of subjects affected by type 2 diabetes, oxidative stress can reduce insulin secretion and, consequently, glucose uptake.

Although research has elucidated many of the mechanisms underlying MetS, its treatment remains a challenge, given the complexity of this disease. For this reason, many research groups are looking for bioactive compounds from food products that can play a preventive role in the onset of this syndrome. Many of these compounds belong to the class of phenols and possess antihypertensive, antihyperglycemic, antihypercholesterolemic, antioxidant, and anti-inflammatory activity, and furthermore, they can produce body weight loss or prevent against body weight gain [25,26].

Among the potentially used preventing approaches to counteract MetS and obesity, the inhibition of α-glucosidase, α-amylase, and lipase was one of the most applied. In fact, the inhibition of carbohydrate hydrolyzing enzymes delays carbohydrate digestion with a consequent hypoglycaemic effect, whereas the inhibition of pancreatic lipase reduces the absorption of ingested fats with a consequent hypolipidemic effect [27,28].

Therefore, herein, we report, for the first time, the pomological characteristics, chemical profile, and nutraceutical properties of different extracts obtained from Prunus cerasifera cv ‘Alimena’, a new bloody pulp cultivar from Sicily. The anthocyanin (TAC), flavonoid (TFC), and total phenol (TPC) contents were spectrophotometrically measured. The complete phytochemical profile was assessed using LC-ESI/LTQOrbitrap/MS analysis. A multitarget approach was applied to assess antioxidant activity (ABTS, DPPH, β-carotene bleaching, and FRAP assays). The inhibitory activity against key enzymes involved in MetS was also assessed.

2. Materials and Methods

2.1. Chemicals and Reagents

All chemicals utilized in this study were purchased from VWR International (Milan, Italy) and Sigma-Aldrich Chemical Co., Ltd. (Milan, Italy).

2.2. Plant Material

The research was carried out on a new accession of Prunus cerasifera L. named ‘Alimena’ and identified in an agricultural area in the territory of Alimena, Sicily (Italy) at an altitude of 675 m s/l, (37°41′25″ N; 14°05′53″ E). From the selected natural tree, budsticks have been collected for developing a small experimental orchard with 50 trees grafted onto P. cerasifera myrobalan 29C.

The orchard was established in 2015, and standard growing techniques have been applied since then. The planting density was 5 m × 5 m, fully irrigated during summer and managed by adopting spontaneous cover crops during the winter-spring season. Winter and summer pruning was performed yearly; fruit thinning was not necessarily due to a regular crop density recorded at fruit set.

2.3. Morphological Description

Morphological description was carried out by applying the Guidelines for the Characterization of Plant, Livestock and Microbial Genetic Resources approved based on the National Agricultural Biodiversity Plan of the Italian Ministry of Agriculture [29]. The Guidelines were drafted based on the international descriptors approved by UPOV [30] and contain references to plant traits considered essential for the characterization of plum tree accessions with the aim of distinguishing and defining their uniqueness.

Application of the guidelines involves the observation of multiple characters related to the tree and morphological characteristics of vegetative and reproductive organs. Leaves and wood samples were taken from mature trees during the vegetative-reproductive season, and at the same time, all observations of tree habits were recorded. At maturity, a sample of 100 fruits was subjected to morphological analysis (height, width, and thickness of the drupe and stone), as well as to qualitative analysis (skin and pulp color, titratable acidity, and soluble sugar content). For this purpose, fruits were randomly taken from the mass harvested at maturity from 5 plants of the same age. The samples were transported to the laboratory with refrigerated facilities so as not to suffer any damage or spoilage.

2.4. Extraction Procedure

A total of 500 g of ripe fruits of P. cerasifera were cleaned, stone removed, and homogenized into puree (PA, 380 g) using a food processor. To determine the water quantity, 50 g of puree, once freeze-dried, to give 7.90 g of extract (content of water: 84.2%). Three hundred grams of PA were extracted for seven days at r.t. with 600 mL of acetone. The solvent was evaporated to give, after freeze-drying, 35.5 g of dry extract (PB). Then, 2.5 g of PB, after dilution with deionized water (≈15 mL) and then extracted with butanol (8 × 10 mL). The butanolic extracts were evaporated to give, after freeze-drying, 0.63 g of dry material (PC). The aqueous layer was freeze-dried to give 1.8 g of extract (PD). As an alternative extraction method, 20 g of PA was mixed with organic solution [≈120 mL, acetone/methanol/water/formic acid (40:40:20:0.1, v/v/v/v)] [31,32] and the mixture was allowed to stand at 4 °C for 24 h. The crude was filtered and washed with 120 mL of the same solution. The supernatants were combined, evaporated under vacuum at 37 °C, and freeze-dried to obtain 2.51 g of new extract (PF).

2.5. Total Phenol (TPC), Flavonoid (TFC), and Anthocyanin Contents (TAC)

Total phenol content (TPC) and total flavonoid content (TFC) were evaluated as previously described by Leporini et al. [33,34]. The differential pH method was used for total anthocyanin content (TAC) quantification [35].

2.6. LC-HRMS Analysis

The LC-ESI/HRMS analysis was carried out on a system of liquid chromatography consisting of a Thermo Ultimate RS 3000 UHPLC coupled online to a Q-Exactive hybrid quadrupole Orbitrap high-resolution mass spectrometer (UHPLC-Q-Orbitrap) (Thermo Fisher Scientific, Bremen, Germany), fitted with a HESI II (heated electrospray ionization) probe, working in both negative and positive ionization mode.

In order to allow the chromatographic separation, a Luna C-18 column (RP-18, 2.0 × 150 mm, 5 nm; Waters; Milford, MA, USA), set at a temperature of 30 °C, and a linear gradient, obtained by using mobile phase 0.1% formic acid in water, v/v (A), and 0.1% formic acid in acetonitrile, v/v (B), from 5 to 55% of B, in 20 min, at a flow rate of 0.2 mL/min, were used. 5 μL of each extract, dissolved in water/acetonitrile 1:1 v/v (0.25 mg/mL), were injected by the autosampler.

To allow negative and positive ions analysis, the HESI source parameters were set as follows: spray voltage at −2.50 kV and 3.30 kV, respectively; sheath gas at 50 arbitrary units (a.u.); auxiliary gas at 10 and 15 a.u., respectively; auxiliary gas heater temperature at 300 °C; capillary temperature at 300 °C; S-lens RF value at 50 a.u.

HRMS and HRMS/MS analyses were carried out by experiments of full (mass range: m/z 150–1400) and data-dependent scan (dd-MS² topN = 5) at resolutions of 70,000 and 17,500, respectively. A normalized collision energy (NCE) of 30 was used. For each sample, three replicates were performed. Data collection and analysis were carried out by using the manufacturer’s software (Xcalibur 2.2).

2.7. In Vitro Evaluation of Antioxidant Potential and Relative Antioxidant Capacity Index

The antioxidant activity was assessed by using two radical scavenging test: 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, β-carotene bleaching test and Ferric Reducing Ability Power (FRAP). All the procedures were previously detailed [36]. The Relative Antioxidant Capacity Index (RACI) was applied to evaluate the sample characterized by the highest activity [33].

2.8. Pancreatic Lipase Inhibitory Activity

The evaluation of pancreatic lipase inhibitory activity was assessed as previously described by Loizzo et al. [37].

2.9. Evaluation of α-Amylase and α-Glucosidase Inhibitory Activity

For α-amylase and α-glucosidase inhibitory activity tests, the procedure previously reported was adopted [36].

2.10. Statistical Analysis

Linear regression, assessment of repeatability, calculation of average, relative standard deviation (SD), and Pearson’s correlation coefficient (r) were calculated by using Microsoft Excel 2010 software (Redmond, WA, USA). The results were expressed as the means of three different experiments ± SD. The inhibitory concentration 50% (IC₅₀) was calculated by using Prism GraphPad Prism version 4.0 for Windows (GraphPad Software, San Diego, CA, USA).

Parametric data were statistically analyzed by using one-way analysis of variance (ANOVA) followed by Tukey’s posthoc test by using Prism GraphPad Prism version 4.0 for Windows. Differences at * p < 0.05 were statistically significant, while at ** p < 0.01, they were highly significant.

3. Results and Discussion

3.1. Morphological Data

All data related to the description of morphological traits provided by the applied descriptors are given in Table 1. All data related to the measurements of the fruits, seeds, and leaves, as well as of the fruit quality characteristics, are given in Table 2. The data reported revealed that the ‘Alimena’ accession had morphological characteristics of uniqueness, mainly related to the average fruit size (41.3 g), which is generally larger than that of the other P. cerasifera cultivars known in the Mediterranean basin. The color of the skin and pulp, therefore, give these fruits distinguishable traits that are unmatched in the varietal panorama of myrobalans, confirming, moreover, the character of low resistance to handling and transport.

Table 1.

Application of criteria for describing the morphological traits of plum tree accessions on ‘Alimena’ myrobalan based on a list of descriptors prepared under the National Agricultural Biodiversity Plan.

GlBA Code	UPOV Code	Descriptor	Reference Cultivar	Level of Expression
1	1	Tree vigor
		High	Valor	7
2	-	Tree habit
		Upright	Jefferson	2
6	61	Blooming time
		Early	Ruth Gerstetter	3
10	38	Flower: shape of the petals
		Rounded	Czar	3
12	17	Leaf blade: Length/Width ratio
		Medium	D’Ente	5
13	18	Leaf blade: shape
		Elliptic	D’Ente	2
20	62	Ripening time
		Early	Bonne de Bry	3
21	43	Fruit dimension
		Small	Hauszwetsche	3
22	44	Fruit shape
		Rounded	Fortune	3
23	50	Skin color
		Red	Victoria	6
24	51	Pulp color
		Red	Bountiful	6
25	52	Fruit consistency
		Medium	Zucchella	5
26	53	Pulp sweetness
		High	Imperial Prune	7
27	54	Seed-pulp adherence
		Adherent	Jori’s Plum	3
29	56	Seed shape
		Elliptic large	Regina Claudia	3

All data related to measurements of fruits, seeds, and leaves, as well as for fruit quality characteristics, are given in Table 2.

Table 2.

Data on morphological descriptive traits related to fruit, seed, and leaf.

	Fruit		Seed		Leaf
	Length	Width	Length	Width	Length	Width
cm	3.32 ± 0.06	3.41 ± 0.09	2.14 ± 0.02	1.48 ± 0.06	6.11 ± 0.11	3.31 ± 0.04

Data are reported to mean ± Standard Deviation (SD) (n = 3).

3.2. Total Phytochemical Content (TPC, TFC, and TAC)

The pulp obtained from the P. cerasifera ‘Alimena’ fruits was subjected to different extractions with several solvents (acetone, butanol, water, methanol, etc.) to evaluate the impact of the solvent on the phytochemical content. The presence of several compounds with different structures and polarities can drastically affect their solubility [38]. Polar solvents (MeOH, EtOH, and water) were used for the isolation of polyphenols and glycosides from plants. The most common ones are mixtures of water with ethanol and methanol. Ethanol is a good solvent for polyphenol extraction and is safe for human consumption, whereas acetone and ethyl acetate have been used for the extraction of medium molecular weight metabolites, such as terpenoids and flavonoid aglycones [39].

The PF sample resulted in the richest TPC and TFC, with values of 97.63 mg gallic acid equivalent (GAE)/100 g FW and 0.96 mg quercetin equivalent (QE)/100 g FW, respectively, followed by the PC samples, whereas PD was richest in TAC (55.33 mg cyanidine-3-O-glucoside/100 g FW) (Table 3).

Table 3.

Phytochemicals content in the selection of myrobalan bloody pulp fruits extract.

Sample	TPC (mg GAE/100 g FW)	TFC (mg QE/100 g FW)	TAC (Cyanidine-3-O-glucoside/100 g FW)
PF	97.63 ± 6.45 a	0.96 ± 0.08 a	39.38 ± 2.09 b
PC	89.61± 2.98 b	0.80 ± 0.06 b	20.24 ± 1.45 c
PD	34.52 ± 2.85 c	0.23 ± 0.04 c	55.33 ± 3.83 a
Sign.	**	**	**

Data are reported as mean ± standard deviation (SD) (n = 3). Differences within and between groups were evaluated by one-way ANOVA, followed by Tukey’s multiple-range test. The results followed by different letters in the same column are significantly different. ** Significance at p < 0.05.

Previously, the TPC content of P. cerasifera ‘Mirabolano’, P. domestica cv ‘President’, and P. salicina cv ‘Shiro’ at different stages of development was analyzed [40]. All plumes exhibited the highest TPC at the date of commercial harvesting—at about 100 days for ‘Mirabolano’, 130 days for ‘President’, and more than 110 days for “Shiro”. TPC values in a range from 1.34 to 6.11 g/kg FW were found for the red and purple myrobalan plum fruits, respectively [31]. Values from 1.74 to 3.75 g/Kg FW were recorded for the Stanley and French Damson fresh plums, respectively [41].

A lower TPC content was found by Gündüz et al. [8], who investigated P. cerasifera selections from Turkey and found values between 136.8 to 583.1 mg GAE/kg FW for ‘Ozark Premier’, and ‘Selection No. 3’, respectively. On the contrary, our data are lower than those found for P. divaricata “Demal” and P. domestica ‘Sugar plum’, with TPC values of 169.6 and 172.4 mg GAE/100 g, respectively [40]. TFC values from 12.1 to 29.1 mg rutin equivalent/100 g were found for ‘Demal’ and P. domestica ‘Red plum’, respectively [42]. TPC values ranging from 177–365 mg GAE/100 g were found for P. divaricate yellow and black, respectively [43].

Gil et al. [44] analyzed several Californian flesh plums and found that ‘Black Beaut’ was richer in TPC and TCC in comparison to ‘Angeleno’, ‘Red Beaut’, ‘Wickson’, and ‘Santa Rosa’ cultivars. Moreover, several research papers demonstrated that qualitative and quantitative variability in TPC, is often related to different genetic factors and developmental stages [45].

Our data on TAC are in line with those reported for P. cerasus varieties ‘Kántorjánosi’, ‘Újfehértói fürtös’, and ‘Debreceni bötermö’ (TAC values of 21, 56, and 63 mg cyanidine-3-O-glucoside/100 g FW, respectively) but lower than those found for the varieties ‘Csengödi csokros’ and ‘Cigánymeggy (TAC values of 295 and 206 mg cyanidine-3-O-glucoside/100 g FW, respectively) [46]. A higher TAC was found for P. domestica ‘Santa Rosa’ and ‘African Rose’, with values of 164.13 and 326.83 mg cyanidine-3-O-glucoside/100 g FW, respectively, and for P. cerasifera from Georgia (109.77 mg cyanidine-3-O-glucoside/100 g FW) [47,48].

3.3. LC-HRMS Analysis

The LC-HRMS profiles of the PC, PD, and PF extracts highlighted the occurrence of several metabolites in P. cerasifera, the structures of which could be assigned by a comparison between the molecular formulae, fragmentation patterns, and retention times and the literature data and metabolite databases, allowing us to putatively identify hydroxycinnamic acid derivatives, flavonols, flavan-3-ols and proanthocyanidins, anthocyanins, organic acids, sugar alcohols (and their derivatives), glycosylated hydroxybenzaldehyde and benzylic alcohol derivatives, glycosyl terpenates, and glycosylated aliphatic alcohol derivatives (Table 4) [37,49,50,51,52,53,54]. Except for compounds 28 and 67, which were previously described in the Rosaceae family [55,56] but not in the genus Prunus, and for compounds 35, 36, 43, and 54 described in families other than Rosaceae [57,58,59], to the best of our knowledge, most of these compounds have already been detected in plants belonging to the genus Prunus [60,61,62,63,64,65,66,67,68,69,70,71,72,73] but not in the species cerasifera. Only compounds 1, 2, 5, 7, 10, 12, 15, 18, 20, 29, 34, 42, 58, and 75 have already been described in this species [31,45,74,75,76,77,78].

Table 4.

Metabolites identified in PF, PC, and PD extracts.

n	Rt (min)	Compound	Molecular Formula	Error (ppm)	[M − H]− (m/z)	(−)HRMS/MS	[M + H]+ (m/z)	(+)HRMS/MS	PF	PC	PD
1	1.72	Hexose sugar alcohol	C6H14O6	0.34	181.0708	163.0601 (C6H11O5), 101.0231 (C4H5O3), 89.0231 (C3H5O3), 71.0125 (C3H3O2), 59.0126 (C2H3O2)			√√	√√	√√
2	1.79	Quinic acid	C7H12O6	0.71	191.0551	173.0445 (C7H9O5), 127.0389 (C6H7O3), 111.0440 (C6H7O2), 93.0333 (C6H5O), 85.0282 (C4H5O2)			√√	√√	√√
3	1.82	(Hexosyl sugar alcohol)-malic acid	C10H18O10	0.32	297.0823	181.0708 (C6H13O6), 133.0131 (C4H5O5), 115.0024 (C4H3O4), 101.0231 (C4H5O3), 89.0231 (C3H5O3), 71.0125 (C3H3O2), 59.0125 (C2H3O2)	321.0793 [M + Na]+	205.0687 (C6H14O6Na), 187.0582 (C6H12O5Na), 157.0111 (C4H6O5Na)	√√	√√	√√
4	1.85	Ketohexosyl-malic acid	C10H16O10	−0.81	295.0669	179.0553 (C6H11O6), 133.0130 (C4H5O5), 101.0231 (C4H5O3), 89.0231 (C3H5O3), 71.0125 (C3H3O2), 59.0125 (C2H3O2)	319.0633 [M + Na]+	301.0535 (C10H14O9Na), 259.0432 (C8H12O8Na), 229.0321 (C7H10O7Na), 203.0530 (C6H12O6Na), 185.0424 (C6H10O5Na), 157.0110 (C4H6O5Na)	√√	√√	√√
5	2.61	Citric acid	C6H8O7	2.15	191.0190	111.0075 (C5H3O3), 87.0074 (C3H3O3)			√√	√√	√√
6	7.63	3-(cis)-O-caffeoylquinic acid	C16H18O9	3.87	353.0881	191.0553 (C7H11O6), 179.0340 (C9H7O4), 135.0440 (C8H7O2)			√√	√√	√
7	7.94	3-(trans)-O-Caffeoylquinic acid	C16H18O9	3.86	353.0881	191.0552 (C7H11O6), 179.0341 (C9H7O4), 135.0440 (C8H7O2)			√√	√√	√
8	8.43	Caffeoyl hexoside	C15H18O9	3.94	341.0880	179.0339 (C9H7O4), 161.0233 (C9H5O3)			√√	√√	√
9	8.65	Coumaroyl dihexoside	C21H28O13	3.82	487.1465	307.0817 (C15H15O7), 163.0399 (C9H7O3), 145.0283 (C9H5O2)			√√	√√	√
10	8.74	Cyanidin 3-O-hexoside	C21H21O11	1.52	447.0939 [M − 2H]−		449.1085 [M]+	287.0556 (C15H11O6)	√√	√√	√√
11	8.80	Dimeric B-type proanthocyanidins	C30H26O12	3.49	577.1361	289.0721 (C15H13O6)			√√	√	—
12	8.98	Cyanidin 3-O- hexoside	C21H21O11	−0.24	447.0937 [M − 2H]−		449.1077 [M]+	287.0553 (C15H11O6)	√√	√√	√√
13	9.05	(Benzyl)hexose-hexoside	C19H28O11	2.46	431.1559/477.1615 [(M + FA) − H]−	269.1037 (C13H17O6), 161.0445 (C6H9O5), 113.0231 (C5H5O3), 101.0231 (C4H5O3)			√√	√√	√√
14	9.10	Coumaroyl dihexoside	C21H28O13	2.57	487.1459	163.0390 (C9H7O3), 145.0283 (C9H5O2)			√√	√√	√
15	9.13	Cyanidin 3-O-rutinoside	C27H31O15	−0.26	593.1517 [M − 2H]−	284.0324 (C15H8O6)	595.1656 [M]+	449.1083 (C21H21O11), 287.0551 (C15H11O6)	√√	√	√√
16	9.38	dimeric B-type proanthocyanidins	C30H26O12	3.72	577.1362	289.0724 (C15H13O6)			√√	√	—
17	9.45	3-O-coumaroylquinic acid	C16H18O8	3.16	337.0929	191.0552 (C7H11O6), 163.0390 (C9H7O3), 119.0490 (C8H7O)			√√	√√	√
18	9.72	5-(trans)-O-caffeoylquinic acid	C16H18O9	3.74	353.0880	191.0553 (C7H11O6)			√√	√√	√
19	9.82	4-O-caffeoylquinic acid	C16H18O9	3.86	353.0881	191.0553 (C7H11O6), 179.0338 (C9H7O4), 173.0445 (C7H9O5), 135.0440 (C8H7O2)			√√	√√	√
20	9.83	Catechin/Epicatechin	C15H14O6	2.89	289.0715	245.0815 (C14H13O4), 205.0500 (C11H9O4), 179.0344 (C9H7O4)			√√	√√	√
21	10.03	5-O-Feruloylquinic acid	C17H20O9	3.40	367.1036	193.0499 (C10H9O4), 191.1560 (C7H11O6), 173.0448 (C7H9O5), 161.0231 (C9H5O3), 134.0363 (C8H6O2)			√√	√√	—
22	10.19	Coumaroyl-(acetyl)hexose-hexoside isomer	C23H30O14	3.70	529.1571	341.1092 (C12H21O11), 307.0825 (C15H15O7), 163.0389 (C9H7O3), 145.0284 (C9H5O2)			√√	√√	√
23	10.35	Dimeric B-type proanthocyanidins	C30H26O12	1.12	577.1347	289.0720 (C15H13O6)			√√	√	—
24	10.40	Benzylhexose pentoside	C18H26O10	−1.36	401.1450/447.1504 [(M + FA) − H]−	269.1031 (C13H17O6), 161.0446 (C6H9O5)	425.1412 [M + Na]+	293.0997 (C13H18O6Na)	√√	√√	√√
25	10.48	Feruloyl hexoside isomer	C16H20O9	3.69	355.1037	193.0496 (C10H9O4), 175.0391 (C10H7O3)			√√	√√	—
26	10.49	(Benzyl)hexose-dihexoside	C25H38O16	2.00	593.2089	415.1607 (C19H27O10), 269.1032 (C13H17O6)			√√	√√	√√
27	10.55	Coumaroyl-(acetyl)hexose-hexoside isomer	C23H30O14	0.31	529.1570	341.1088 (C12H21O11), 307.0824 (C15H15O7), 163.0391 (C9H7O3), 145.0284 (C9H5O2)	553.1530 [M + Na]+	391.1009 (C17H20O9Na), 349.0896 (C15H18O8Na)	√√	√√	√
28	10.56	(Benzaldehyde)hexose-pentoside	C18H24O11	3.59	415.1250/461.1310 [(M + FA) − H]−	121.0282 (C7H5O2)			√√	√√	√√
29	10.59	Methyl caffeoylquinate isomer	C17H20O9	2.92	367.1034	179.0341 (C9H7O4), 173.0449 (C7H9O5), 161.0235 (C9H5O3)			√√	√√	—
30	10.65	5-(cis)-O-caffeoylquinic acid	C16H18O9	3.60	353.0880	191.0553 (C7H11O6)			√√	√√	—
31	10.81	Feruloyl hexoside isomer	C16H20O9	3.27	355.1035	193.0502 (C10H9O4), 175.0391 (C10H7O3)			√√	√√	—
32	10.85	Coumaroyl-(acetyl)hexose-hexoside isomer	C23H30O14	3.75	529.1572	341.1088 (C12H21O11), 307.0824 (C15H15O7), 163.0391 (C9H7O3), 145.0284 (C9H5O2)			√√	√√	√
33	10.90	4-O-coumaroylquinic acid	C16H18O8	3.18	337.0929	191.0557 (C7H11O6), 173.0446 (C7H9O5), 163.0387 (C9H7O3)			√√	√√	√√
34	10.97	Catechin/Epicatechin	C15H14O6	2.89	289.0715	245.0814 (C14H13O4), 205.0503 (C11H9O4), 179.0344 (C9H7O4)			√√	√√	√
35	11.00	Feruloyl-(acetyl)hexose-hexoside isomer	C24H32O15	2.47	559.1671	175.0391 (C10H7O3)			√√	√√	—
36	11.26	Feruloyl-(acetyl)hexose-hexoside isomer	C24H32O15	2.85	559.1673	175.0392 (C10H7O3)			√√	√√	—
37	11.43	Coumaroyl-(acetyl)hexose-hexoside isomer	C23H30O14	3.75	529.1572	341.1095 (C12H21O11), 307.0820 (C15H15O7), 163.0394 (C9H7O3), 145.0284 (C9H5O2)			√√	√√	√
38	11.51	Methyl coumaroylquinate isomer	C17H20O8	3.83	351.1088	145.0283 (C9H5O2)			√√	√√	√√
39	11.61	Dimethyl-hydroxy-decadienedioate hexoside	C18H28O10	3.74	403.1614	241.1080 (C12H17O5), 197.1178 (C11H17O3), 181.0866 (C10H13O3), 59.0126 (C2H3O2)			√√	√√	√
40	11.81	Methyl coumaroylquinate isomer	C17H20O8	3.83	351.1088	145.0284 (C9H5O2), 119.0492 (C8H7O)			√√	√√	√√
41	11.93	Coumaroyl-(diacetyl)dihexoside isomer	C25H32O15	3.00	571.1675	307.0824 (C15H15O7), 163.0389 (C9H7O3), 145.0284 (C9H5O2)			√√	√√	√
42	12.22	Methyl caffeoylquinate isomer	C17H19O9	2.97	367.1034	179.0341 (C9H7O4), 161.0238 (C9H5O3)			√√	√√	—
43	12.26	Hexyl-dihexoside isomer	C18H34O11	3.27	471.2084 [(M + FA) − H]−	263.1499 (C12H24O6), 161.0444 (C6H9O5), 101.0231 (C4H5O3)			√√	√√	√
44	12.37	Coumaroyl-(diacetyl)dihexoside isomer	C25H32O15	2.65	571.1673	341.1088 (C12H21O11), 307.0834 (C15H15O7), 163.0388 (C9H7O3), 145.0283 (C9H5O2)	595.1644 [M + Na]+	391.1009 (C17H20O9Na), 349.0900 (C15H18O8Na), 331.0790 (C15H16O7Na), 287.0756 (C10H16O8Na), 167.0315 (C6H8O4Na)	√√	√√	√
45	12.50	Delphinidin-3-O-rutinoside	C27H31O16	0.18	609.1466 [M − 2H]−		611.1608 [M]+	303.0501 (C15H11O7)	√√	√	√√
46	12.59	Dimethyl-octadienedioate hexoside	C16H24O9	2.93	359.1347	197.0810 (C10H13O4), 153.0910 (C9H13O2), 59.0125 (C2H3O2)			√√	√√	√
47	12.64	Coumaroyl-(diacetyl)dihexoside isomer	C25H32O15	1.30	571.1665	341.1084 (C12H21O11), 307.0829 (C15H15O7), 163.0390 (C9H7O3), 145.0284 (C9H5O2)	595.1636 [M + Na]+	391.1004 (C17H20O9Na), 349.0899 (C15H18O8Na), 331.0804 (C15H16O7Na), 287.0732 (C10H16O8Na), 167.0317 (C6H8O4Na)	√√	√√	√
48	12.66	Delphinidin-3-O-hexoside	C21H21O12	0.34			465.1029 [M]+	303.0502 (C15H11O7)	√√	√√	√√
49	12.79	Dimeric A-type proanthocyanidins	C30H24O12	1.45	575.1204	539.0960 (C30H19O10), 423.0726 (C22H15O9), 407.0771 (C22H15O8), 327.0513 (C17H11O7), 289.0723 (C15H13O6), 287.0562 (C15H11O6), 285.0409 (C15H9O6)	577.1349	287.0552 (C15H11O6)	√√	√√	√
50	12.92	Isorhamnetin 3-O-rutinoside	C28H32O16	3.78	623.1630	315.0503 (C16H11O7), 314.0431 (C16H10O7)			√√	—	—
51	13.08	Quercetin-3-O-hexoside	C21H20O12	0.12	463.0889	301.0346 (C15H9O7)	465.1028	303.0502 (C15H11O7)	√√	√√	√
52	13.12	Isorhamnetin-3-O-pentose-hexoside	C27H30O16	1.18	609.1472	315.0509 (C16H11O7)	611.1614	317.0657 (C16H13O7)	√√	—	—
53	13.20	Abscisic acid hexoside	C21H30O9	1.59			449.1789 [M + Na]+	287.1258 (C15H20O4Na)	√√	√√	—
54	13.26	Dicrotalic acid (Benzyl)hexoside	C19H26O10	3.91	413.1458	269.1039 (C13H17O6)			√√	√√	√
55	13.36	Quercetin-3-O-di-pentoside	C25H26O15	1.65	565.1207	301.0325 (C15 H9 O7)	567.1354	303.0506 (C15 H11 O7+)	√√	√√	√
56	13.43	Dimeric A-type proanthocyanidins	C30H24O12	1.35	575.1204	539.0959 (C30H19O10), 407.0771 (C22H15O8), 327.0507 (C17H11O7), 289.0719 (C15H13O6), 287.0560 (C15H11O6), 285.0405 (C15H9O6)	577.1348	287.0553 (C15H11O6)	√√	√√	√
57	13.59	Quercetin-3-O-pentoside	C20H18O11	1.98	433.0779	301.0345 (C15H9O7)	435.0930	303.0503 (C15H11O7)	√√	√√	√
58	13.68	Quercetin 3-O-rutinoside	C27H30O16	1.18	609.1468	301.0349 (C15H9O7)	611.1614	303.0516 (C15H11O7)	√√	√√	√
59	13.84	Coumaroyl-(triacetyl)dihexoside isomer	C27H34O16	3.81	613.1786	163.0387 (C9H7O3), 145.0284 (C9H5O2)			√√	√√	√
60	14.01	Quercetin-3-O-pentoside	C20H18O11	1.06	433.0778	301.0349 (C15H9O7)	435.0927/457.0744 [M + Na]+	303.0501 (C15H11O7)	√√	√√	√
61	14.16	Coumaroyl-(triacetyl)dihexoside isomer	C27H34O16	1.21	613.1782	383.1196 (C14H23O12), 307.0813 (C15H15O7), 163.0393 (C9H7O3), 145.0284 (C9H5O2)	637.1747 [M + Na]+	391.0995 (C17H20O9Na), 373.0882 (C17H18O8Na), 287.0734 (C10H16O8Na), 167.0315 (C6H8O4Na)	√√	√√	√
62	14.17	Quercetin-3-O-deoxyhexoside	C21H20O11	3.36	447.0937	301.0349 (C15H9O7)	449.1085		√√	√√	√
63	14.18	Isorhamnetin 3-O-hexoside	C22H22O12	1.60	477.1044	314.0431 (C16H10O7)	479.1192	317.0659 (C16H13O7)	√√	—	—
64	14.32	Methyl (hexosyl)-O-coumarate isomer	C16H20O8	0.86			363.1054 [M + Na]+	201.0524 (C10H10O3Na), 185.0427 (C6H10O5Na)	√√	√√	—
65	14.33	Coumaroyl-(triacetyl)dihexoside isomer	C27H34O16	1.03	613.1783	341.1087 (C12H21O11), 163.0390 (C9H7O3), 145.0284 (C9H5O2)	637.1746 [M + Na]+	391.0992 (C17H20O9Na), 373.0886 (C17H18O8Na), 287.0739 (C10H16O8Na), 167.0317 (C6H8O4Na)	√√	√√	√
66	14.36	Quercetin-3-O-(acetyl)hexoside	C23H22O13	1.25	505.0996	300.0273 (C15H8O7)	507.1140	303.0502 (C15H11O7)	√√	√√	√
67	14.65	[(Dihydroxybenzoyloxy)-dihydroxyphenyl]acetate methyl ester	C16H14O8	1.54	333.0620	197.0446 (C9H9O5), 165.0183 (C8H5O4)	335.0767	137.0235 (C7H5O3)	√√	√√	√
68	14.68	Coumaroyl-(triacetyl)dihexoside isomer	C27H34O16	1.31	613.1783	383.1187 (C14H23O12), 341.1085 (C12H21O11), 163.0390 (C9H7O3), 145.0284 (C9H5O2)	637.1747 [M + Na]+	391.0998 (C17H20O9Na), 373.0895 (C17H18O8Na), 287.0758 (C10H16O8Na)	√√	√√	√
69	14.91	Coumaroyl-(triacetyl)dihexoside isomer	C27H34O16	1.31	613.1786	383.1197 (C14H23O12), 341.1094 (C12H21O11), 307.0833 (C15H15O7), 163.0391 (C9H7O3), 145.0283 (C9H5O2)	367.1747 [M + Na]+	391.1006 (C17H20O9Na), 373.0890 (C17H18O8Na), 287.0744 (C10H16O8Na), 167.0317 (C6H8O4Na)	√√	√√	√
70	15.14	Azelaic acid	C9H16O4	2.86	187.0970	125.0960 (C8H13O)			√√	√√	√√
71	15.28	Quercetin-3-O-(Acetyl)rutinoside	C29H34O17	1.28	651.1583	301.0351 (C15H9O7)	653.1721		√√	√√	√
72	16.62	Coumaroyl-(tetraacetyl)dihexoside isomer	C29H36O17	1.04	655.1893	163.0390 (C9H7O3), 145.0284 (C9H5O2)	679.1852 [M + Na]+	373.0889 (C17H18O8Na), 329.0846 (C12H18O9Na)	√√	√√	√
73	16.86	Coumaroyl-(tetraacetyl)dihexoside isomer	C29H36O17	1.31	655.1892	163.0395 (C9H7O3), 145.0285 (C9H5O2)	679.1854 [M + Na]+	433.1112 (C19H22O10Na), 373.0940 (C17H18O8Na), 209.0423 (C8H10O5Na)	√√	√√	√
74	17.17	Coumaroyl-(tetraacetyl)dihexoside isomer	C29H36O17	0.69	655.1893	383.1197 (C14H23O12), 163.0393 (C9H7O3), 145.0284 (C9H5O2)	679.1849 [M + Na]+	433.1115 (C19H22O10Na), 391.1004 (C17H20O9Na), 373.0901 (C17H18O8Na), 329.0835 (C12H18O9Na), 209.0422 (C8H10O5Na)	√√	√√	√
75	17.81	Quercetin	C15H10O7	2.73	301.0351	178.9977 (C8H3O5), 151.0025 (C7H3O4), 121.0283 (C7H5O2)			√√	√√	—
76	19.76	Coumaroyl-(pentaacetyl)dihexoside isomer	C31H38O18	3.34	697.1998	145.0282 (C9H5O2)			√√	√√	—
77	19.95	Coumaroyl-(pentaacetyl)dihexoside isomer	C31H38O18	3.17	697.1996	145.0283 (C9H5O2)			√√	√√	—

Legend: √√ = detectable; √ = detectable at low intensity level (1.1 × 10³ < Normalized Level < 4.0 × 10⁴); — = not detectable.

Among the most represented group of metabolites, the derivatives of hydroxycinnamic acid, some differences could be appreciated among the three P. cerasifera extracts (Table 4). PF and PC showed, in fact, a higher number of metabolites belonging to this class with respect to the PD extract. It is noteworthy that compounds 21, 25, 31, 35, and 36, containing a feruloyl unit in their structure, and compounds 29, 42, and 64, corresponding to methyl ester derivatives of quinic or coumaroyl acid, were not detectable in PD. Moreover, the caffeoyl- and coumaroyl-quinic acid isomers 6–7, and 17–19, along with the caffeoylhexose 8 and the coumaroyl dihexoside isomers 9 and 14 were detectable in PD at a minor intensity level with respect to the other two extracts, as well as the mono-acylated forms of coumaroyldihexoside isomers (22, 27, 32, and 37). Furthermore, in PD, the coumaroyldihexoside isomers with two to four acetyl groups were even less intense (41, 44, 47, 59, 61, 65, 68–69, and 72–74), while the penta-acetylated forms (76–77) were not detectable at all (Table 4). It is noteworthy that compounds 41, 44, and 47 were more evident in PC than in PF.

Regarding the second most representative group of metabolites identified in P. cerasifera—flavonols—once again, the PF extract was the most complete of the three, highlighting, besides the quercetin derivatives, the occurrence of isorhamnetin derivatives (50, 52, and 63) that were not evident in the other two extracts. Furthermore, PC showed the occurrence of flavonols at higher intensity levels than PD (Table 4). Flavan-3-ols (20 and 34) and proanthocyanidins A-type (49, 56) occurred in all tested extracts, even if at lower intensity in PD, which lacked the dimers of proanthocyanidins B-type (11, 16, and 23), which were, in turn, more evident in PF than in PC (Table 4). Glycosylated derivatives of cyanidin and delphinidin (10, 12, 15, 45, and 48) could be observed in PF, PC, and PD, with PC showing the occurrence of the rutinoside derivatives of both anthocyanins (15 and 45) at a minor intensity level.

Simple organic acids like 2 and 5 or the nonanedioic acid 70, as well as derivatives of malic acid with sugar alcohol like sorbitol or galactitol (3), or with a ketohexose like fructose (4), were detectable in all tested extracts, unlike the glycosylated forms of the dicrotalic and abscisic acids (54 and 53), with the first being more evident in PF and PC and the second no detectable in PD (Table 4).

Analogously, the glycosylated derivatives of benzyl alcohol or hydroxybenzaldehyde (13, 24, 26, and 28) (differing in sugars) could be highlighted in all the extracts, contrary to glycosylated terpenates (39 and 46), which were mainly present in PF and PC, as well as the glycosylated form of hexanol (43), likely due to their higher lipophilicity (Table 4).

3.4. ‘Alimena’ Myrobalan Antioxidant Potential

The antioxidant activities of myrobalan bloody pulp fruit extracts were assessed using different in vitro methods, namely FRAP, β-carotene bleaching test, ABTS, and DPPH assays (Table 5).

Table 5.

‘Alimena’ Myrobalan Antioxidant Potential.

Sample	DPPH Test (IC50 μg/mL)	ABTS Test (IC50 μg/mL)	β-Carotene Bleaching Test (IC50 μg/mL)	FRAP Test (μM Fe(II)/g)
PF	19.61 ± 2.98 a	1.19 ± 0.06 a	39.38 ±2.09 c	58.72 ± 2.76 b
PC	29.63 ± 6.45 b	2.46 ± 0.08 b	11.32 ±1.76 a	64.90 ± 3.52 c
PD	39.02 ± 4.45 c	2.97 ± 0.09 c	20.24 ±1.45 b	53.01 ± 2.20 a
Sign.	**	**	**	**
Positive control
Ascorbic acid	5.04 ± 0.81	1.72 ± 0.14
Propyl gallate			0.09 ± 0.04
BHT				63.26 ± 2.31

Differences within and between the groups were evaluated by one-way ANOVA followed by Tukey’s multiple-range test. The results followed by different letters in the same column are significantly different. ** Significance at p < 0.05.

The PF sample showed the highest radical scavenging activity, with IC₅₀ values of 19.61 and 1.19 μg/mL for the DPPH and ABTS assays, respectively.

In general, by comparing the data obtained from the two different radical scavenging tests, it was possible to note that the DPPH^· radical is less sensible than the ABTS⁺ in our samples. In fact, IC₅₀ values in the range 19.61–39.02 and 1.19–2.97 μg/mL for the DPPH and ABTS tests, respectively, were obtained. Data from the ABTS test are in the same order of potency as ascorbic acid. The ‘Alimena’ pulp extracts ferric-reducing potential was evaluated by FRAP testing, revealing reduced iron in the samples, with a potency comparable to the positive control BHT.

Pearson’s correlation coefficient evidenced r values of 0.79, 0.80, and 0.91 for TPC, FRAP, ABTS, and DPPH, respectively. A similar trend was also observed for TFC, wherein r values of 0.73, 0.85, and 0.95 for FRAP, ABTS, and DPPH were recorded, respectively. No positive correlation was found for TAC and the antioxidant data.

Our data on radical scavenging potential are better than those reported for Indian P. cerasifera with IC₅₀ values of 10.09 and 45.40 μg/mL for ABTS and DPPH assays, respectively [79]. On the contrary, our data obtained by FRAP testing resulted lower than those found in the “Sugar plum” cultivar (563.8 μM Fe (II)/g) [44].

The variability of antioxidant activity during the harvesting of P. domestica cv ‘President’, P. salicina cv ‘Shiro’, and P. cerasifera myrobalan was investigated. By comparing the data on the ‘Alimena’ myrobalan with those obtained by Moscatello et al. [40], it emerges that at the commercial maturity stage, the radical scavenging DPPH activity of our samples is significantly higher, with IC₅₀ values in the range 56.22–76.46 µg/mL vs. 19.61–39.02 µg/mL, while similar results can be observed with the plum ‘President’ (IC₅₀ in the range 28.63–30.35 µg/mL). Similar results against DPPH were also found for the P. domestica ‘African Rose’ and ‘Santa Rosa’ extracts (IC₅₀ values of 13.923 and 18.416 μg/mL, respectively) [47]. On the contrary, when comparing this with domesticated P. domestica, a higher DPPH activity was observed (IC₅₀ in the range 5.2–6.6 µg/mL for black and red fruit, respectively) [43].

Recently, Popović et al. [75] explored different Prunus varieties from Serbia and found high variability in the ability of hydroalcoholic extract to counteract the DPPH^· radical (IC₅₀ in the range 0.83–29.12 mg/mL for steppe cherry and red cherry plum, respectively). However, all data are lower than those found in our extracts.

FRAP values ranging from 11.20 to 44.83 mmol TE/g fresh weight (FW) were found for yellow and purple Chinese myrobalan plum extract, respectively [28], whereas the FRAP values ranged between 0.123 and 0.835 mmol TE/kg FW for ‘Selection 33C 02’ and ‘Selection 31C 18’, respectively [8].

The integration of antioxidant data into the PF sample saw the most active result in terms of antioxidant activity, with the lowest RACI value (0.71) (Figure S1).

3.5. Inhibition of Target Enzymes Useful for the Prevention and Treatment of Hyperglycaemia and Obesity

In our continuous search for foods that are able to prevent MeTs, we have investigated the ability of the bloody pulp of myrobalan, a new variety of Sicilian Prunus, to counteract the enzymes linked with hyperglycaemia and hyperlipidaemia. All investigated extracts exerted inhibitory enzyme activity in a concentration-dependent manner (Table 6). According to Nowicka et al. [80], the extract richest in flavonols (PF) exerted the highest α-amylase inhibitory activity (IC₅₀ value of 34.48 μg/mL). Moreover, the PF sample was found to be more proficient in inhibiting pancreatic lipase, followed by the PD sample, with IC₅₀ values of 29.61 and 38.16 μg/mL, respectively. Values from 49.76 to 78.87 μg/mL were found for the PC and PD samples, respectively, against α-glucosidase. The results of correlation analysis evidenced that a strong positive correlation was found between TPC and α-glucosidase inhibitory activity (r = 0.96) and TAC and lipase inhibitory property (r = 0.80). A weak correlation was found between TFC and α-amylase (r = 0.56).

Table 6.

Enzymes inhibitory activities by ‘Alimena’ myrobalan extracts.

Sample	Lipase (IC50 μg/mL)	α-Amylase (IC50 μg/mL)	α-Glucosidase (IC50 μg/mL)
PF	29.61 ± 1.45 a	34.48 ± 4.22 a	55.27 ± 2.97 b
PC	78.53 ± 2.96 c	54.49 ± 3.87 c	49.76 ± 2.76 a
PD	38.16 ± 1.89 b	51.50 ± 3.24 b	78.87 ± 3.56 c
Sign.	**	**	**
Positive control
Orlistat	3.74 ± 1.01
Acarbose		50.12 ± 1.13	35.55 ± 1.10

Data are reported as mean ± standard deviation (SD) (n = 3). Differences within and between the groups were evaluated by one-way ANOVA, followed by Tukey’s multiple-range test. The results followed by different letters in the same column are significantly different. ** Significance at p < 0.05.

Our data on carbohydrate-hydrolyzing enzymes are in line with those reported by Kołodziejczyk-Czepas [81] for P. spinosa; they found IC₅₀ values in a range from 15.43 to 90.95 μg/mL for hydroalcoholic extract and butanol fraction, respectively, against α-glucosidase, and from 33.47 to 110.12 μg/mL for ethyl acetate and butanol fraction, respectively, against α-amylase. A lower α-amylase inhibitory effect was found by testing the P. ceraus extracts, with IC₅₀ values in a range from 330 to 892 μg/mL for the ‘Cigánymeggy’ and ‘Kántorjánosi’ varieties, respectively [46], and by Popović et al. [75], who investigated different Prunus species (IC₅₀ values in the range 4.61–136.23 mg/mL for P. fruticose and P. pissardi ‘Carriére’, respectively). In the same work authors tested Prunus extracts against α-glucosidase and recognized a low inhibitory activity (IC₅₀ values in the range 0.41–136.23 mg/mL).

Podsędek et al. [82] investigated the effect of water extract obtained from P. persica fruits from Poland and found lower α-glucosidase inhibitory activity in comparison to our data (IC₅₀ value of 264.44 mg/mL) despite a higher TPC content.

Recently, Ullah et al. [83] demonstrated that P. domestica subsp. syriaca (‘Mirabelle’) was able to inhibit the key enzymes involved in MetS. In particular, the hydroethanolic extract inhibited α-amylase, α-glucosidase, and pancreatic lipase, with IC₅₀ values of 7.01, 6.4, 6.0 mg/mL, respectively. All these values are higher than those found in this study.

A perusal analysis of the literature revealed that the inhibition of α-glucosidase should be related to the content of the hydroxycinnamic acid derivatives that are particularly abundant in PF and PC and that exert a more potent inhibitory activity against this enzyme [84].

4. Conclusions

The preservation of agro-biodiversity for the purpose of consumption is at the heart of the targets of SDG No. 12 (Responsible Production and Consumption), demonstrating that the spread of a model of sustainability goes through the choices of products that have very high environmental adaptation. For this reason, the identification of new accessions, their description, and in-depth knowledge of their quality characteristics represents a virtuous model of knowledge development for consumption. The growing awareness of consumers toward the possibility of preventing and/or treating pathologies through certain defined foods represents the driving force of the global market for these types of products. In this context, we have analyzed the chemical profile and bioactivity of three extracts of a new bloody pulp selection of myrobalan (P. cerasifera). The PF extract showed the most promising bioactivity, which is in agreement with its highest phytochemical content. Further in vivo studies are necessary to better understand the biological properties and potential applications for the development of functional foods or nutraceutical products that are useful to consumers with these types of health problems.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/foods12051107/s1, Figure S1. RACI values.

Author Contributions

Methodology: F.S., S.P., M.R.L. and R.T.; software validation: A.N.; formal analysis: A.N., N.B. and R.T.; data curation: A.N., N.B. and M.B.; writing—original draft preparation: M.R.L. and S.P.; writing—review and editing, S.P.; project administration. M.B. and F.S. All authors have read and agreed to the published version of the manuscript.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are available from the authors upon reasonable request.

Conflicts of Interest

The authors declare no conflict of interest.

Funding Statement

This research was carried out within the National Biodiversity Future Center S.c.a.r.l., Piazza Marina 61 (c/o Palazzo Steri) Palermo, Italy, and received funding from the European Union Next-Generation EU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR)—MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4, C.I. CN00000033)—CUP UNIPA B73C22000790001; CUP UNISA D43C22001260001.