Chuan Lian Zi

TOOSENDAN FRUCTUS (川楝子, Chuanlianzi) Szechwan Chinaberry Fruit The ripe fruit of Melia toosendan Sieb. et Zucc. (Fam. Meliaceae). The drug is collected in winter when ripe, removed from foreign matter, and dried. Description Subspherical, 2.0–3.2 cm in diameter. Externally golden-yellow to brownish-yellow, somewhat lustrous, occasionally dented or shrunken, with numerous dark brown dots. Apex bearing the persistent style; base depressed, with a fruit stalk scar. Epicarp leathery, usually separated from the sarcocarp by a cavity. Sarcocarp loose and soft, pale yellow, becoming sticky when moistened with water. Endocarp spherical or ovoid, hard, both ends truncate, with 6–8 longitudinal ribs and 6–8 locules, each locule containing one oblong, blackish-brown seed. Odour characteristic. Taste sour and bitter. Identification (1) Powder Yellowish-brown. Pericarp fibres occurring in bundles, 9–36 μm in diameter, with obtusely rounded ends and heavily thickened walls. The fibres are surrounded by parenchymatous cells containing prisms of calcium oxalate, forming crystal fibres. Stone cells of the pericarp subrounded, irregularly elongated, or polygonal, 14–54 μm in diameter and up to 150 μm long, sometimes with wart-like protuberances or short obtusely rounded branches. Testa cells bright yellow or orange-yellow. Beneath the testa is a single layer of subsquare cells, up to 44 μm in diameter, with heavily thickened walls and slightly sinuous longitudinal striations, adjoining the pigment layer. Epidermal cells polygonal in surface view, with fine, dense granular striations. Cells of the pigment layer containing reddish-brown contents. Crystal cells of the testa 13–27 μm in diameter, with walls of variable thickness; the thicker-walled cells resembling stone cells. Their lumina contain pale yellow, yellowish-brown, or reddish-brown contents together with minute prisms of calcium oxalate about 5 μm in diameter. Clusters of calcium oxalate 5–27 μm in diameter. (2) To 2 g of the powder add 80 mL of water and ultrasonicate for 1 hour. Allow to cool and centrifuge. Extract the supernatant successively with three 25-mL portions of dichloromethane. Combine the dichloromethane extracts and evaporate to dryness. Dissolve the residue in 2 mL of methanol as the test solution. Prepare a solution of 1 g of Toosendan Fructus Reference Drug in the same manner as the reference drug solution. Dissolve Toosendanin CRS in methanol to prepare a solution containing 1 mg/mL as the reference solution. Carry out the method for Thin-Layer Chromatography (0502) using silica gel G as the coating substance and a mixture of dichloromethane and methanol (16:1) as the mobile phase. Apply separately 10 μL of the test solution, reference drug solution, and reference solution to the plate. After development, remove the plate and dry in air. Spray with p-dimethylaminobenzaldehyde TS. Heat at 105°C until the spots become distinct. The spots obtained with the test solution correspond in position and colour to those obtained with the reference drug solution and the reference solution. Water Not more than 12.0% (0832, Method 2). Total Ash Not more than 5.0% (2302). Extractives Carry out the method for determination of water-soluble extractives (2201, Hot Extraction Method). Not less than 32.0%. Assay Carry out the method for High-Performance Liquid Chromatography–Mass Spectrometry (0512 and 0431). Chromatographic and spectrometric system and system suitability Use octadecylsilane-bonded silica gel as the stationary phase. Use a mixture of acetonitrile and 0.01% formic acid solution (31:69) as the mobile phase. Use a single-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) negative-ion interface. Monitor m/z 573 in selected ion recording (SIR) mode. The number of theoretical plates of the column shall be not less than 8000, calculated with reference to the peak of toosendanin. Reference solution Accurately weigh a quantity of Toosendanin CRS. Dissolve in methanol to prepare a solution containing 2 μg/mL. Test solution Accurately weigh 0.25 g of the medium powder into a stoppered conical flask. Accurately add 50 mL of methanol and weigh. Heat under reflux for 1 hour. Allow to cool. Weigh again. Replenish the loss of solvent with methanol. Mix well. Filter. Use the subsequent filtrate as the test solution. Procedure Inject accurately 2 μL of the reference solution and 1–2 μL of the test solution, respectively, into the chromatograph. Determine and calculate the content. The drug contains 0.060–0.20% of toosendanin (C₃₀H₃₈O₁₁), calculated with reference to the dried drug. Prepared Slices Processing Toosendan Fructus Remove foreign matter. Break into pieces before use. Description As required for the crude drug. Identification As required for the crude drug. Water and Total Ash As required for the crude drug. Extractives As required for the crude drug. Assay As required for the crude drug. Toosendan Fructus (Stir-baked) Cut the clean Toosendan Fructus into thick slices or coarse fragments. Stir-bake according to the method for simple stir-baking (0213) until the outer surface becomes brown. Description Semispherical thick slices or irregular fragments. Externally charred yellow, occasionally with charred spots. Odour slightly aromatic. Taste sour and bitter. Identification As required for the crude drug. Water Not more than 10.0%, following the method for the crude drug. Total Ash Not more than 4.0%, following the method for the crude drug. Extractives As required for the crude drug. Assay Contains 0.040–0.20% of toosendanin (C₃₀H₃₈O₁₁), following the method for the crude drug. Property and Flavor Cold; bitter; slightly toxic. Meridian Tropism Liver, Small Intestine, and Bladder meridians. Actions To soothe the liver, clear heat, regulate qi, relieve pain, and kill parasites. Indications Liver qi stagnation transforming into fire, distending pain in the chest, hypochondrium, epigastrium, and abdomen, pain due to hernia, and abdominal pain caused by intestinal parasites. Administration and Dosage 5–10 g. For external use, apply an appropriate amount after grinding into fine powder or preparing as a liniment. Storage Preserve in a well-ventilated and dry place, protected from insects.