Table 2.
Summary of the various techniques used to prepare analytical kudzu root for the determination of their isoflavones.
| Analytes | Extraction Method | Extraction Solvent | Condition | Separation and Purification | Analysis Method | Productive Rate (%) |
References |
|---|---|---|---|---|---|---|---|
| Isoflavones | Sonication extract (PLs) and reflux extract (PLr) | Methanol | Ultrasonic bath (frequency of 40 kHz; Power Sonic 520 W, at room temperature for 2 h.) | Semi-preparative reversed-phase HPLC | HPLC | 7.99–10.57 | [46] |
| Puerarin, daidzin, daidzein | Refluxing extraction | 80% ethanol | Refluxed in a water bath at 80 °C for 2 h | MSPE Magnetic solid-phase extraction |
ZIF-8-pressurized capillary electrochromatography (pCEC) | - | [47] |
| Puerarin and total flavonoids | Immersion method | 30% ethanol | Water bath (70 °C) | - | UPLC-MS, NIR, and UV-Vis portable | - | [48] |
| Nine isoflavones | Ultrasonic-assisted extraction | Methanol | Sonicated at 40 °C for 20 min | - | HPLC | - | [8] |
| puerarin | SPE | 80% methanol | Sonicated for 30 min | SPE | LC-MS/MS | - | [49] |
| Six isoflavones | Refluxing extraction and ultrasonic-assisted extraction | 50% methanol | Ultrasonic bath (frequency of 40 kHz; Power Sonic 120 W) | - | UPLC | - | [50] |
| Isoflavones | Ultrasonic-assisted extraction based on NADES | NADESs: choline chloride and citric acid at a 1:2 molar ratio | Ultrasonic bath (frequency of 37 kHz; Power Sonic 580 W, at 60 °C for 3 h.) | Reversed stationary phase column | HPLC-DAD | 1.09 ± 0.006 | [51] |
| Isoflavone | Ultrasonic-assisted extraction | Water or ethanol 65° | Amplitude = 65% nominal power, cycle = 1, 40 °C ± 1 °C | - | HPLC-PDA | - | [52] |
| Puerarin and daidzein | Ultrasonic-assisted extraction | Methanol-glacial acetic acid (100:1) | Ultrasonic bath (frequency of 40 kHz; Power Sonic 100 W) | - | Non-aqueous capillary electrophoresis (NCAE) | - | [53] |
| Puerarin | Ultrasonic-assisted extraction | 70% ethanol | Ultrasonic bath (Power Sonic 350 W at 60 °C for 3 h.) | Acid hydrolysis | HPLC-IR | - | [54] |
| Puerarin and daidzein | Ultrasonic-assisted extraction | Water | - | - | HPLC | - | [55] |
| Total flavonoids | Ultrasonic-assisted extraction | 35% ethanol | Ultrasonic bath (frequency of 53 kHz; Power Sonic 200 W) | - | UV | 2.76 | [56] |
| Flavonoids | Microwave-assisted extraction | 60% ethanol, | Microwave power 340 W for 4 min | - | UV | - | [57] |
| Six isoflavones | Refluxing extraction | 30% ethanol | - | - | HPLC | - | [58] |
| Puerarin | Ultrasonic-assisted extraction | 70% ethanol | Ultrasonic bath (frequency of 42 kHz; Power Sonic 70 W) | - | UV | - | [59] |
| Flavonoids | Ultrasonic-assisted extraction | 75% ethanol | Ultrasonic extraction 30 min | - | UV | - | [60] |
| Nine isoflavones | SPE | 20% ethanol solution (containing 0.1% formic acid) | - | - | pCEC | - | [61] |
| Puerarin and daidzein | Ultrasonic-assisted extraction | Ethanol | - | - | Differential pulse voltammetry | - | [62] |
| flavonoids | Refluxing extraction | 60% ethanol | Reflux extraction 1.5 h | - | UV-Vis | - | [63] |
| Flavonoids | Microwave-assisted extraction | 42% ethanol | Microwave power 828 W for 23 min | - | UV | 11.74 | [64] |
| Puerarin | Ultrasonic-assisted extraction | 58% ethanol | Ultrasonic bath at 70 °C for 32 min | - | UV-Vis | - | [65] |
| Puerarin | Microwave-assisted extraction | 70% ethanol | Mrowave 9.7 min | column C18 | HPLC | - | [66] |
| flavonoids | Immersion method | 40% ethanol | Water bath at 80 °C for 2 h | - | UV | 3.06 | [67] |
| Four isoflavones | Ultrasonic-assisted extraction | 30% ethanol | Ultrasonic extraction 1 h | - | HPLC | - | [68] |
| Three isoflavones | Ultrasonic-assisted extraction | 50% ethanol | Ultrasonic extraction 40 min | - | HPLC | - | [69] |
| Six isoflavones | Ultrasonic-assisted extraction | 70% methanol | Ultrasonic bath (frequency of 40 kHz; Power Sonic 250 W, for 3 h.) | - | HPLC | - | [70] |
| Five isoflavones | Ultrasonic-assisted extraction | 70% methanol | Ultrasonic extraction 1 h | - | HPLC | - | [71] |
| Puerarin | Ultrasonic-assisted extraction | 0.6 mg/mL β-CD | Ultrasonic extraction at 40 °C for 1 h | - | Three-dimensional fluorescence spectrum | - | [72] |
| Flavonoids | Ultrasonic-assisted extraction | 40% ethanol | Ultrasonic bath (Power Sonic 300 W for 20 min) | - | GC/MS | - | [73] |
| Puerarin and daidzein | Refluxing extraction | 80% ethanol | - | - | HPLC | - | [74] |
| Puerarin | Microwave-assisted ionic liquid extraction | 1.0 mol/L ionic liquids | Microwave power 400 W for 8 min | - | UV | - | [75] |
| Four isoflavones | Immersion method | 30% ethanol | - | - | HPLC | - | [76] |
| Total flavonoids and puerarin | Refluxing extraction | Methanol | Heat reflux extraction 1 h | - | UV-Vis and HPLC | - | [77] |
| Puerarin | Microwave-assisted enzymatic extraction technology | Cellulose dose 190 U/g | Microwave power 450 W for 7 s | - | UV | 8.87 | [78] |
-: Not reported.