Bu Zha Ye

MICROCOS FOLIUM 布渣叶 (Buzhaye) Paniculate Microcos Leaf Source Microcos Folium is the dried leaf of Microcos paniculata L. (Family Malvaceae). The leaves are collected in summer and autumn, separated from branches and other foreign matter, and dried either in the shade or in the sun. Description The leaves are mostly crumpled or broken. When intact, they are ovate-suborbicular to ovate-oblong, measuring 8–18 cm long and 4–8 cm wide. The upper surface is yellowish-green, greenish-brown, or yellowish-brown. The apex is acuminate, the base obtuse to rounded and slightly oblique, and the margin serrulate. There are three basal veins, with pinnate lateral veins and reticulate veinlets. The petiole is short, and both the veins and petiole are pubescent. The texture is papery and easily broken. Odour: Slight. Taste: Mild, slightly sour and astringent. Identification (1) Powder Pale yellowish-green. Epidermal cells subpolygonal or subrounded. Stomata anomocytic. Non-glandular hairs of two types: Stellate hairs with numerous branches, each branch containing several septa. Unicellular hairs. Fibres slender, occurring in bundles, with relatively thick walls and distinct pits. Prismatic crystals of calcium oxalate common. Cluster crystals of calcium oxalate 5–20 μm in diameter. (2) Thin-Layer Chromatography To 1 g of the powdered drug add 50 mL of water and reflux for 2 hours. Filter and concentrate the filtrate to 30 mL. Extract twice with ethyl acetate (30 mL and 25 mL). Combine the ethyl acetate extracts, evaporate to dryness, and dissolve the residue in 1 mL of absolute ethanol as the test solution. Prepare the reference drug solution in the same manner using 1 g of Microcos Folium reference drug. Carry out thin-layer chromatography using silica gel G as the coating substance and a mixture of dichloromethane, butanone, formic acid, and water (10:1:0.1:0.1) as the mobile phase. Apply 2 μL each of the test and reference solutions to the plate. After development, dry the plate and examine under UV light at 365 nm. The fluorescent spots in the chromatogram obtained with the test solution correspond in position and colour to those obtained with the reference drug solution. Foreign Matter Not more than 2.0%. Water Not more than 12.0%. Total Ash Not more than 8.0%. Extractives Determine ethanol-soluble extractives using the hot extraction method with dilute ethanol as the solvent. Not less than 17.0%. Assay Carry out high-performance liquid chromatography (HPLC). Chromatographic Conditions Stationary phase: Octadecylsilane bonded silica gel Mobile phase: Methanol – 0.4% phosphoric acid (30:70) Detection wavelength: 339 nm Theoretical plates: Not fewer than 3000, calculated with reference to the vitexin peak. Reference Solution Accurately weigh Vitexin CRS and dissolve in 70% methanol to obtain a solution containing 20 μg/mL. Test Solution Accurately weigh 2.5 g of the powdered drug (through No. 3 sieve) into a stoppered conical flask. Add 50 mL of 70% methanol, weigh, ultrasonicate (250 W, 33 kHz) for 1 hour, cool, replenish any loss of solvent with 70% methanol, mix thoroughly, and filter. Use the subsequent filtrate as the test solution. Procedure Inject 10 μL each of the reference solution and test solution into the HPLC system and calculate the content. The drug contains not less than 0.040% of vitexin (C₂₁H₂₀O₁₀), calculated on the dried basis. Property and Flavor Cool; slightly sour. Meridian Tropism Spleen and Stomach meridians. Actions Promotes digestion Relieves food stagnation Clears heat Eliminates dampness Indications Food retention Common cold with fever Damp-heat jaundice Administration and Dosage 25–30 g Storage Preserve in a dry place.