Chong Wei Zi

LEONURI FRUCTUS (茺蔚子, Chongweizi) Motherwort Fruit The fruit is the dried ripe fruit of Leonurus japonicus Houtt. (Fam. Labiatae). The aerial parts are cut in autumn when the fruit is ripe, dried in the sun, and the fruits are collected by threshing and cleaned. Description Trihedral, 2–3 mm long, about 1.5 mm wide. Externally greyish-brown with dark-colored spots; one end slightly broad and truncate, gradually narrowing toward the opposite obtusely acute end. Pericarp thin. Cotyledons nearly white and oily. Odour slight; taste bitter. Identification (1) Powder Yellowish-brown to dark brown. Exocarp cells slightly radially elongated in transverse section, variable in length, forming numerous raised ridges with yellow reticulate, unlignified cells in the center. Surface view showing subpolygonal cells with striated cuticle; reticulate cells possessing striated thickened walls. Endocarp sclerenchyma slightly tangentially elongated in transverse section; inner walls extremely thick, outer walls thin; lumina eccentric and containing prisms of calcium oxalate. Surface view showing stellate sclerenchyma or indistinct cell boundaries with obvious calcium oxalate prisms. Mesocarp cells subpolygonal with thin, sinuous walls. Testa epidermal cells subsquare with slightly thickened, sinuous walls containing pale yellowish-brown contents. Endosperm cells filled with fatty oil droplets and aleurone grains. (2) Thin-layer chromatography To 3 g of the powder add 30 mL ethanol, heat under reflux for 1 hour, cool, filter, and concentrate the filtrate to about 5 mL. Apply the concentrate to a chromatography column (10 mm internal diameter) packed with: Activated charcoal — 0.5 g Neutral aluminium oxide (100–120 mesh) — 2 g Elute with 30 mL ethanol, collect the eluate, evaporate to dryness, and dissolve the residue in 0.5 mL ethanol as the test solution. Prepare the reference solution by dissolving stachydrine hydrochloride CRS in ethanol to obtain a concentration of 5 mg/mL. Carry out Thin-layer Chromatography (0502) using silica gel G as the coating substance and a mixture of: n-Butanol Hydrochloric acid Water (4 : 1 : 0.5) as the mobile phase. Apply 10 μL each of the test solution and reference solution. After developing, remove the plate, dry in air, and spray with diluted potassium iodobismuthate TS. The spot obtained with the test solution corresponds in position and colour to that obtained with the reference solution. Water Not more than 7.0% (0832, Method 2). Total Ash Not more than 10.0% (2302). Extractives Carry out the method for determination of ethanol-soluble extractives (2201, hot extraction method), using ethanol as the solvent. Not less than 17.0%. Assay Carry out the method for High-Performance Liquid Chromatography (0512). Chromatographic system and system suitability Use octadecylsilane-bonded silica gel as the stationary phase. Use a mixture of methanol and 0.3% phosphoric acid solution (5:95) as the mobile phase. Detection wavelength: 277 nm. The number of theoretical plates shall be not less than 4000, calculated with reference to the peak of stachydrine. Reference solution Accurately weigh Stachydrine Hydrochloride CRS. Dissolve in methanol to prepare a solution containing 0.2 mg/mL. Test solution Accurately weigh 1 g of the coarse powder (through No. 3 sieve) into a stoppered conical flask. Accurately add 25 mL of ethanol. Heat under reflux for 1 hour. Cool and weigh. Replace the loss of solvent with ethanol. Filter. Evaporate 10 mL of the filtrate to dryness. Dissolve the residue in 10 mL of methanol. Filter. Use the subsequent filtrate as the test solution. Procedure Inject accurately 10 μL each of the reference solution and the test solution into the chromatograph. Calculate the content. It contains not less than 0.050% of stachydrine hydrochloride (C₇H₁₄ClNO₂), calculated with reference to the dried drug. Prepared Slices Processing Remove foreign matter. Description As required for the crude drug. Identification As required for the crude drug. Water As required for the crude drug. Total Ash As required for the crude drug. Extractives As required for the crude drug. Assay As required for the crude drug. Property and Flavor Slightly cold; pungent and bitter. Meridian Tropism Liver and Pericardium meridians. Actions To invigorate the blood, regulate menstruation, clear the liver, and improve vision. Indications Menstrual irregularities, dysmenorrhea, amenorrhea, postpartum abdominal pain due to blood stasis, red and painful eyes, blurred vision, dizziness, and headache. Administration and Dosage 5–10 g. Storage Preserve in a dry place.