. 2019 May 8;9(5):179. doi: 10.3390/biom9050179

Table 1.

Plectranthus spp. extraction yields according to solvent and extraction method, and radical scavenging activity (RSA) of the extracts (100 μg/mL) in the DPPH assay.

Plant	Solvent	Extraction Method ^a	Dry Residue (g)	Yield (mg/g)	Extract	RSA ^b (%)
Plectranthus madagascariensis	Water	INF	0.23 ± 0.10	2.3	E1	<50
		MW	0.11 ± 0.04	1.1	E2	<50
		DEC	0.22 ± 0.02	2.2	E3	<50
	Acetone	US	0.151	1.5	E4	<50
	Acetone	MA	0.377	3.8	E5	<50
	Methanol	US	0.656	6.6	E6	89.0
	Methanol	MA	1.146	11.5	E7	64.8
	scCO₂	SCFE	0.394	0.01	E8	<50
	Acetone	R-SCFE	0.885	0.03	E9	<50
Plectranthus neochilus	Water	INF	0.26 ± 0.04	2.6	E10	<50
		MW	0.15 ± 0.04	1.5	E11	<50
		DEC	0.22 ± 0.01	2.2	E12	<50
	Acetone	US	0.180	1.8	E13	<50
	Acetone	MA	0.125	1.3	E14	<50
	Methanol	US	0.702	7.0	E15	64.9
	Methanol	MA	0.600	6.0	E16	62.3
	scCO₂	SCFE	0.251	0.8	E17	<50
	Acetone	R-SCFE	0.417	1.4	E18	<50
Plectranthus porcatus	Water	INF	n/d	n/d	E19	<50
	Water	MW	n/d	n/d	E20	<50
	Acetone	US	0.865	8.7	E21	<50
	Acetone	MA	0.872	8.7	E22	<50
	Methanol	US	1.566	15.7	E23	60.8
	Methanol	MA	2.237	22.4	E24	65.9
	scCO₂	SCFE	0.191	0.64	E25	<50
	Acetone	R-SCFE	0.868	2.9	E26	<50

^a DEC, decoction; INF, infusion; MA, maceration; MW, microwave-assisted extraction; SCFE, supercritical fluid extraction; R-SCFE, re-extraction of the SCFE remaining plant material; US, ultrasound-assisted extraction; n/d, not determined. ^b Positive control (ascorbic acid): 93.4%. In bold the most relevant results. DPPH: 2,2-diphenyl-1-picrylhydrazyl.