金荞麦

English text reference: *Chinese Pharmacopoeia (2020 Edition) *

Overview

Rhizoma Fagopyri Dibotryis is the dried rhizome and root of Fagopyrum dibotrys (D.Don) Hara (Fam. Polygonaceae). The drug is collected in winter, removed from stem and root hairs, washed clean, and dried in the sun.

Description

Rhizomes irregularly massed or cylindrical, often with tuberous branches, 3-15 cm long, 1-4 cm in diameter; surface brownish-brown, with transverse nodes and longitudinal wrinkles, densely dotted with pustular pores, and with concave circular root scars and residual root hairs. Texture hard, not easily broken, fracture pale yellow-white or pale reddish-brown, with radial texture, central medullary part darker in color. Odour, slight; taste, slightly astringent.

Identification

（1）The powder is light brown. Numerous starch grains are present, single grains are spherical, elliptical or ovate, 5-48 μm in diameter, with hilum punctate, stellate, fissured or bird-like, located in the center or biased to one end, large grains show layering; compound grains consist of 2-4 sub-grains; half-compound grains are visible. Wood fibers are bundled, 10-38 μm in diameter, with oblique or cross-shaped pits. Calcium oxalate cluster crystals are 10-62 μm in diameter. Wood parenchyma cells are square or elliptical, 28-37 μm in diameter, up to about 100 μm in length, with slightly thickened walls and sparse pits. Vascular tracheids and libriform fibers are 21-83 μm in diameter.

（2）Take 2.5 g of the drug, add 20 ml of methanol, let stand for 1 hour, heat under reflux for 1 hour, cool, filter, concentrate the filtrate to 5 ml as the test solution. Take another 1 g of Rhizoma Fagopyri Dibotryis, prepare the reference solution in the same way. Take rutin CRS, add methanol to produce a solution containing 1 mg per 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 toluene-acetic acid-ethyl acetate-methanol-formic acid (1: 2: 0.2: 0.1) as the mobile phase. Apply separately to the plate 5-10 μl of each of the test solution, the reference solution, and the reference drug solution. After developing and removal of the plate, dry in air. Spray with a 25% solution of phosphomolybdic acid in ethanol, heat at 110 °C to the spots clear. The spots in the chromatogram obtained with the test solution correspond in position and colour to the spots in the chromatograms obtained with the reference drug solution and the reference solution.

Examination

Water

Not more than 15.0 per cent <0832, method 2>.

Total ash

Not more than 5.0 per cent <2302>.

Extractives

Carry out the method for determination of ethanol-soluble Extractives <2201, the hot maceration method>, using diluted ethanol as the solvent, not less than 14.0 per cent.

Assay

Carry out the method for high performance liquid chromatography <0512>.

Chromatographic conditions and system suitability test

Use octadecylsilane bonded silica gel as the filler; use acetonitrile-0.004% phosphoric acid solution (10: 90) as the mobile phase; detection wavelength is 280 nm. The theoretical plate number calculated from the peak of rutin should not be less than 6000.

Preparation of reference solution

Take an appropriate amount of rutin CRS, accurately weigh, add the mobile phase to produce a solution containing 25 μg per ml, and mix well.

Preparation of test solution

Take about 2 g of the coarse powder of the drug, accurately weigh, place it in a stoppered conical flask, accurately add 50 ml of diluted ethanol, seal tightly, accurately weigh, let stand for 1 hour, heat under reflux for 1 hour, cool, weigh again, make up for the weight loss with diluted ethanol, shake well, filter, accurately take 25 ml of the filtrate, concentrate under reduced pressure (50-70 °C) to near dryness, wash the residue with a mixed solution of acetonitrile-water (10: 90) in portions, transfer the washing solution to a 10 ml volumetric flask, add a mixed solution of acetonitrile-water (10: 90) to the mark, shake well, centrifuge (at a speed of 3000 rpm) for 5 minutes, accurately take 5 ml of the supernatant, apply to a polyamide column (30-60 mesh, inner diameter 1.0 cm, column length 15 cm, wet packing), elute with 50 ml of water, discard the eluate, elute with 100 ml of ethanol, collect the eluate, concentrate under reduced pressure (50-70 °C) to near dryness, dissolve the residue with a mixed solution of acetonitrile-water (10: 90), transfer to a 10 ml volumetric flask, dilute with a mixed solution of acetonitrile-water (10: 90) to the mark, shake well, and obtain the test solution.

Assay method

Accurately take 20 μl of each of the reference solution and the test solution, inject into the liquid chromatograph, and determine.

Calculated on the dried basis, the content of rutin (C15H14O6) should not be less than 0.030%.

Prepared slices

Rhizoma Fagopyri Dibotryis

Processing

Eliminate Foreign matter, wash clean, soften briefly, cut into thick slices, and dry.

Description

In irregular thick slices. Externally brown, some falling off. Cut surface pale yellowish-white or pale brownish-red, radiately striated, some with pith in deeper colour. Odour slight; taste slightly astringent.

含量测定 ｜ Assay

It contains oot less than 0. 020 per cent of (-)-epicatechin (C15H14O6), following the method for the crude drug.

Identification

As required for the crude drug.

Examination

As required for the crude drug.

Extractives

As required for the crude drug.

Property

Cold.

Flavor

Slightly pungent and astringent.

Meridian tropism

Lung meridian.

Actions

To clear heat and detoxify, promote suppuration and eliminate stasis.

Indications

Used for lung abscess with expectoration of pus, lung heat with cough and dyspnea, and mastitis with swelling and pain.

Dosage

15-45 g.

Administration

Decocted with water or yellow rice wine in a sealed container over water.

Storage

Preserve in a dry place, protect from mold and moth.

金荞麦

Text reference: Chinese Pharmacopoeia (2015 Edition)

Overview

Golden Buckwheat Rhizome is the dried rhizome of Fagopyrum dibotrys (D. Don) Hara (Fam. Polygonaceae). The drug is collected in winter, removed from stem and rootlet, washed clean, and dried.

Description

In irregular masses or cylindrical, mostly with tubercular branches, sometimes with remains of stems at apex, 3-15 cm long, 1-4 cm in diameter. Externally brown, with transverse annulated-nodes and longitudinal wrinkles, scattered with numerous dotted lenticels, and showing dent and rounded root scars and remains of rootlets. Texture hard and uneasily broken, facture pale yellowish-white or pale brownish-red, radiately striated. Pith in the centre deeper in colour. Odour, slight; taste, slightly astringent.

Identification

（2）取本品2.5g，加甲醇20ml，放置1小时，加热回流1小时，放冷，滤过，滤液浓缩至5ml，作为供试品溶液。另取金荞麦对照药材1g，同法制成对照药材溶液。再取表儿茶素对照品，加甲醇制成每1ml含1mg的溶液，作为对照品溶液。照薄层色谱法（通则0502）试验，吸取供试品溶液5～10µl、对照药材溶液和对照品溶液各5µl，分别点于同一硅胶G薄层板上，以甲苯-乙酸乙酯-甲醇-甲酸（1：2：0.2：0.1）为展开剂，展开，取出，晾干，喷以25%磷钼酸乙醇溶液，在110℃加热至斑点显色清晰。供试品色谱中，在与对照药材色谱和对照品色谱相应的位置上，显相同颜色的斑点。

Examination

Water

Not more than 15.0 per cent <0832, method 2>.

Total ash

Not more than 5.0 per cent <2302>.

Extractives

Carry out the method for determination of ethanol-soluble extractives <2201, the hot extraction method>, using dilute ethanol as the solvent, not less than 14.0 per cent.

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 and a mixture of acetonitrile and 0.004% solution of phosphoric acid (10 : 90) as the mobile phase. As detector a spectrophotometer set at 280 nm. The number of theoretical plates of the column is not less than 6000, calculated with the reference to the peak of (一)-epicatechin.

Reference solution

Weigh accurately a quantity of (一)-epicatechin CRS, dissolve in the mobile phase to produce a solution containing 25 μg per ml.

Test solution

Weigh accurately 2 g of the powder to a stoppered conical flask, add accurately 50 ml of dilute ethanol, stopper tightly, weigh and stand for 1 hour. Heat under reflux on a water bath for 1 hour, cool and weigh again, replenish the loss of the solvent with dilute ethanol, mix well and filter. Concentrate exactly 25 ml of the successive filtrate to near dryness in vacuum (50-70℃). Wash the residue with a mixture of acetonitrile and water (10 : 90) in quantities, combine the washings to a 10 ml volumetric flask, dilute with the same mixture to volume, mix well and centrifuge at 3000 rpm for 5 minutes. Apply accurately 5 ml of the supernatant to a polyamide column (30-60 mesh, 1.0 cm in inner diameter, 15 cm long, packed by wet method), elute with 50 ml of water and 100 ml of ethanol successively, discard the water eluates, collect the ethanol eluates and concentrate to near dryness in vacuum (50-70℃). Dissolve the residue in a mixture of acetonitrile and water (10 : 90), transfer to a 10 ml volumetric flask, dilute with the same mixture to volume and mix well.

Procedure

Inject accurately 20 μl of each of the reference solution and the test solution, respectively, into the column, and calculate the content.

It contains not less than 0.030 per cent of (一)-epicatechin (C15H14O6), calculated with reference to the dried drug.

Prepared slices

Golden Buckwheat

Processing

Eliminate foreign matter, wash clean, soften thoroughly, cut into thick slices, and dry.

Property

Mild pungent and astringent.

Flavor

Cool.

Meridian tropism

Lung meridian.

Actions

To clear heat, remove toxin, expel pus and eliminate stasis.

Indications

Lung abscess with pyemesis, wheezing and cough caused by lung-heat, swelling and pain caused by tonsillitis.

Administration and dosage

15-45 g, mixed with water or yellow rice wine, and simmered in an airtight container for oral administration.

Storage

Preserve in a dry place, protected from mould and moth.