Chi Xiao Dou

VIGNAE SEMEN (赤小豆, Chixiaodou) Rice Bean Vigna umbellata (Thunb.) Ohwi et Ohashi or Vigna angularis (Willd.) Ohwi et Ohashi (Fam. Leguminosae). The plants are uprooted in autumn when the fruits are ripe but not yet dehiscent, dried in the sun, and the seeds are collected, cleaned of foreign matter, and dried again. Description Seed of Vigna umbellata Oblong and slightly flattened, 5–8 mm long and 3–5 mm in diameter. Externally purplish-red, dull or slightly lustrous. Hilum linear, raised, situated on one side and inclined toward one end, white, approximately two-thirds the length of the seed, with a longitudinal groove in the middle. An indistinct ridge present on the opposite side. Texture hard and difficult to break. Cotyledons two, milky white. Odour slight. Taste slightly sweet. Seed of Vigna angularis Short cylindrical. Both ends slightly truncate or obtusely rounded. Approximately 4–6 mm in diameter. Externally dark brownish-red and lustrous. Hilum not raised. Identification (1) Transverse section Seed of Vigna umbellata Testa consisting of a single layer of palisade epidermal cells, becoming two layers at the hilum. Cells contain pale reddish-brown substances with a distinct light line. Supporting cells arranged in one layer, dumbbell-shaped. Beneath them are approximately 10 layers of parenchymatous cells, the inner layers collapsed. Cotyledon cells contain abundant starch granules together with fine prisms and clusters of calcium oxalate. A caruncle occurs outside the palisade cells at the hilum. Within it is a tracheid island, elliptical in shape, with reticulate secondary wall thickening. Aerenchyma occurs on both sides, composed of stellate cells with large intercellular spaces. Seed of Vigna angularis Cotyledon cells occasionally contain fine prisms of calcium oxalate, but no clusters. (2) To 2 g of the powder add 10 mL of 75% ethanol. Ultrasonicate for 30 minutes. Filter. Use the filtrate as the test solution. Prepare a solution of 2 g of Vignae Semen Reference Drug in the same manner as the reference drug solution. Carry out the method for Thin-Layer Chromatography (0502) using silica gel G as the coating substance and a mixture of chloroform, acetic acid, methanol, and water (70:35:10:8) as the mobile phase. Apply separately 5 μL of each solution to the plate. After development, remove the plate and dry in air. Spray with 2% vanillin in sulfuric acid. 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. Water Not more than 14.0% (0832, Method 2). Total Ash Not more than 5.0% (2302). Extractives Carry out the method for determination of ethanol-soluble extractives (2201, Hot Extraction Method) using 75% ethanol as the solvent. Not less than 7.0%. Prepared Slices Processing Remove foreign matter. Sieve to remove dust. Description As required for the crude drug. Identification As required for the crude drug. Water, Total Ash, Acid-insoluble Ash, and Extractives As required for the crude drug. Property and Flavor Neutral; sweet and sour. Meridian Tropism Heart and Small Intestine meridians. Actions To promote urination, reduce edema, remove toxins, and expel pus. Indications Edema, abdominal distension and fullness, tinea pedis with swelling, jaundice with dark urine, wind-dampness-heat bi disorder, abscesses, sores, toxic swellings, and intestinal abscess with abdominal pain. Administration and Dosage 9–30 g. For external use, grind into powder and apply an appropriate amount. Storage Preserve in a dry place, protected from insects.