Identification of Licorice Extract

Identification

(1) Cross-section of this product: the cork layer is several rows of brown cells. Cortex is narrower. Phloem rays broad, more curved, often fissures; fiber bundles, non-woody or slightly wooded, thin-walled cells around the often contain calcium oxalate square crystals; sieve tube group is often deformed due to compression. Formation of layers in bundles is obvious. Xylem rays 3-5 rows of cells wide; ducts more numerous, ca. to 160 μm in diameter; wood fibers in bundles, surrounding thin-walled cells also containing calcium oxalate square crystals. Root center without pith; rhizome center with pith. Powder pale brownish yellow. Fibers in bundles, 8-14 μm in diameter, thick-walled, slightly lignified, surrounding thin-walled cells containing calcium oxalate square crystals, forming crystalline fibers. Calcium oxalate square crystals are common. Ciliated perforated ducts are large, rare reticulate ducts. Cork cells reddish brown, polygonal, slightly lignified.

(2) Take 1g of powder, add 40ml of ether, heat reflux for 1 hour, filtration, dregs add 30ml of methanol, heat reflux for 1 hour, filtration, filtrate evaporation, residue add 40ml of water to make dissolved, extracted with n-butanol for 3 times, 20ml each time, combined with n-butanol, washed with water for 3 times, evaporation, residue add 5ml of methanol to make solved, as a solution for the test product. Take glycyrrhiza glabra control herb 1g, the same method into the control herb solution. Then take ammonium glycyrrhizinate control, add methanol to make a solution containing 2mg per 1ml, as the control solution. According to thin-layer chromatography (Appendix VI B), absorb 1~2μl of each of the above three solutions, respectively, on the same silica gel G thin layer plate prepared with 1% sodium hydroxide solution, with ethyl acetate-formic acid-glacial acetic acid-water (15:1:1:2) as the unfolding agent, unfolding, removing, drying, spraying with 10% ethanol sulfate, and then drying. Sprayed with 10% ethanol sulfate solution, heated at 105 ℃ until the spots showed clear color, and examined under ultraviolet light (365 nm). In the chromatogram of the test article, in the corresponding position with the chromatogram of the control herb, the fluorescent spots of the same color; in the corresponding position with the chromatogram of the control article, the fluorescent spots of the same orange-yellow color.