地黄

English text reference: Chinese Pharmacopoeia (2020 Edition)

Overview

Rehmannia Root is the fresh or dried tuberous root of Rehmannia glutinosa Libosch. (Fam. Scrophulariaceae). The drug is collected in autumn, removed from fibrous roots, rootlet and soil, used fresh, or dried in the sun and cut into thick slices, or dried after being processed with honey. The former is called "Fresh Rehmannia Root" and the latter is called "Raw Rehmannia Root".

Description

Fresh Rehmannia Root

It is spindle-shaped or cylindrical, 8-24 cm long, 2-9 cm in diameter. Outer surface thin, light reddish-yellow, with curved longitudinal wrinkles, bud scars, transverse elongated corky protuberances and irregular scars. Texture, brittle, fracture surface pale yellowish-white, with orange-red oil spots, wood yellowish-white, with radiating arrangement of vessels. Odour, slight; taste, slightly sweet and slightly bitter.

Raw Rehmannia Root

Ii is irregularly massed or long cylindrical, enlarged in the middle, slightly slender at both ends, some small and long strip-shaped, slightly flat and twisted, 6-12 cm long, 2-6 cm in diameter. Surface brownish-black or brownish-grey, extremely wrinkled, with irregular transverse wrinkles. Texture, relatively soft and tough, not easily broken, fracture surface brownish-yellow to black or dark black, glossy, sticky. Odour, slight; taste, slightly sweet.

Identification

(1) Transverse section of the drug: cork cells arranged in rows. Cells of the inner cork layer loosely arranged; numerous secretory cells scattered, containing orange-yellow oil droplets; occasional stone cells. Cortex relatively wide, with fewer secretory cells. Cambium ring-shaped. Xylem rays wide; vessels sparse, arranged radially.

Powdered Raw Rehmannia Root is dark brown. Cork cells are light brown. Thin-walled cells are round, containing round nucleus-like substances. Secretory cells are similar in shape to general thin-walled cells, containing orange-yellow or orange-red oil droplets. There are marginal pitted vessels and reticulate vessels with a diameter of about 92 μm.

Take 2 g of the powder, add 20 ml of methanol, heat under reflux for 1 hour, cool, filter, concentrate the filtrate to 5 ml as the test solution. Take Aconitine CRS, add methanol to produce a solution containing 0.5 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 chloroform-methanol-water (14:6:1) as the mobile phase. Apply separately to the plate 5 μl of each of the above two solutions. After developing and removal of the plate, dry in air. Spray with anisaldehyde test solution, heat at 105°C to the spots clear. The spot in the chromatogram obtained with the test solution corresponds in position and colour to the spot in the chromatogram obtained with the Reference solution.

Take 1 g of the powder, add 50 ml of 80% methanol, treat with ultrasound for 30 minutes, filter, evaporate the filtrate to dryness, dissolve the residue in 5 ml of water, shake with saturated n-butanol 4 times, each time 10 ml, combine the n-butanol solution, evaporate to dryness, dissolve the residue in 2 ml of methanol as the test solution. Take Stachyose 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 ethyl acetate-methanol-formic acid (16:0.5:2) as the mobile phase. Apply separately to the plate 5 μl of the test solution and 2 μl of the Reference solution. After developing and removal of the plate, dry in air. Dip the plate into a 0.1% solution of 2,2-diphenyl-1-picrylhydrazyl in anhydrous ethanol, dry. The spot in the chromatogram obtained with the test solution corresponds in position and colour to the spot in the chromatogram obtained with t he Reference solution.

Examination

Water

Raw Rehmannia Root

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

Total ash

Not more than 8.0 per cent <2302>.

Acid-insoluble ash

Not more than 3.0 per cent <2302>.

Extractives

Carry out the method for determination of water-soluble Extractives <2201>, the cold maceration method, not less than 65.0 per cent.

Assay

Catalpol

Carry out the method for determination of Aucubin <0512> by high performance liquid chromatography.

Chromatographic conditions and system suitability test

Use octadecylsilane bonded silica gel as the filler; use methanol-0.1% phosphoric acid solution (1:99) as the mobile phase; detect at a wavelength of 210 nm. The theoretical plate number calculated based on the peak of Aucubin should not be less than 5000.

Preparation of reference solution

Take an appropriate amount of Aucubin reference substance, accurately weigh, add the mobile phase to make a solution containing 50 μg per ml.

Preparation of test solution

Take the prepared slices of this product (Rehmannia Root) and cut them into small pieces of about 5 mm. After drying under reduced pressure at 80°C for 24 hours, grind them into coarse powder. Take about 0.8 g, accurately weigh, place it in a conical bottle with a stopper, accurately add 50 ml of methanol, weigh, heat reflux for 1.5 hours, cool, weigh again, make up for the lost weight with methanol, shake well, filter, accurately take 10 ml of the filtrate, concentrate to near dryness, dissolve the residue with the mobile phase, transfer to a 10 ml volumetric flask, dilute to the mark with the mobile phase, shake well, filter, and take the filtrate.

Method of determination

Accurately take 10 μl of the reference solution and the test solution, inject them into the liquid chromatograph, and determine.

Raw Dioscorea contains not less than 0.20% catalpol (C15H22O10).

Rehmannioside D

Carry out the method for determination of Rehmannioside D <0512> by high performance liquid chromatography.

Chromatographic conditions and system suitability test

Use octadecylsilane bonded silica gel as the filler; use methanol-0.1% phosphoric acid solution (5:95) as the mobile phase; detect at a wavelength of 203 nm. The theoretical plate number calculated based on the peak of Rehmannioside D should not be less than 5000.

Preparation of reference solution

Take an appropriate amount of Rehmannioside D reference substance, accurately weigh, add 25% methanol to make a solution containing 70 μg per ml.

Preparation of test solution

Take the prepared slices of this product (Rehmannia Root) and cut them into small pieces of about 5 mm. After drying under reduced pressure at 80°C for 24 hours, grind them into coarse powder. Take about 1 g, accurately weigh, place it in a conical bottle with a stopper, accurately add 25% methanol 25ml, weigh, ultrasonicate (power 400 W, frequency 50 kHz) for 1 hour, cool, weigh again, make up for the lost weight with 25% methanol, shake well, centrifuge at high speed for 10 minutes, take the supernatant and filter, and take the filtrate.

Method of determination

Accurately take 10 μl of the reference solution and the test solution, inject them into the liquid chromatograph, and determine.

Raw dihuang contains not less than 0.10% dihuangoside D (C27H42O20).

Prepared slices

Rehmannia Root

Processing

Remove impurities, wash, moisten, cut into thick slices, and dry.

Appearance

This product is round or irregular thick slices. The outer surface is dark brown or brownish-gray, extremely wrinkled, with irregular transverse wrinkles. The cut surface is brownish-yellow to black or jet black, glossy, and sticky. It has a slight odor and a slightly sweet taste.

Identification

(Except for cross-section) same as the crude drug.

Examination

Same as the crude drug.

Extractives

Same as the crude drug.

Assay

Same as the crude drug.

Property

Fresh Rehmannia

Cold.

Prepared Rehmannia

Cold.

Flavor

Fresh Rehmannia

Sweet and bitter.

Prepared Rehmannia

Sweet.

Meridian tropism

Fresh Rehmannia

Heart, Liver, and Kidney meridians.

Prepared Rehmannia

Heart, Liver, and Kidney meridians.

Actions

Fresh Rehmannia

Clearing heat and promoting generation of body fluid, cooling blood and stopping bleeding.

Prepared Rehmannia

Clearing heat and cooling blood, nourishing Yin and promoting the production of body fluid.

Indications

Fresh Rehmannia

It is used for heat disease damaging yin, red tongue with restlessness and thirst, warm toxin causing rashes, vomiting blood, nosebleed, and sore throat.

Prepared Rehmannia

It is used for heat entering the nutrient blood, warm toxin causing rashes, vomiting blood, nosebleed, heat disease damaging yin, red tongue with restlessness and thirst, fluid injury leading to constipation, yin deficiency fever, bone-steaming and consumptive fever, and internal heat with excessive thirst.

Dosage

Fresh Rehmannia

12-30 g.

Prepared Rehmannia

10-15 g.

Administration

None.

Storage

Fresh Rehmannia Root should be buried in sandy soil to prevent freezing; Prepared Rehmannia Root should be stored in a well-ventilated and dry place to prevent mold and moth.

地黄

Text reference: Chinese Pharmacopoeia (2015 Edition)

Overview

Rehmannia Root is the fresh or dried root tuber of Rehmannia glutinosa Libosch. (Fam. Scrophulariaceae). The drug is collected in autumn, removed from root stock, rootlet and soil, used either in fresh state or baked to almost dry. The former is known as “Xian Dihuang” (Fresh Rehmannia Root) and the latter is known as “Sheng Dihuang” (Unprocessed Rehmannia Root).

Description

呈纺锤形或条状，长8～24cm，直径2～9cm。外皮薄，表面浅红黄色，具弯曲的纵皱纹、芽痕、横长皮孔样突起及不规则疤痕。肉质，易断，断面皮部淡黄白色，可见橘红色油点，木部黄白色，导管呈放射状排列。气微，味微甜、微苦。

多呈不规则的团块状或长圆形，中间膨大，两端稍细，有的细小，长条状，稍扁而扭曲，长6～12cm，直径2～6cm。表面棕黑色或棕灰色，极皱缩，具不规则的横曲纹。体重，质较软而韧，不易折断，断面棕黑色或乌黑色，有光泽，具黏性。气微，味微甜。

Identification

Transverse section: Cork consisting of several layers of cells. Parenchymatous cells of phellderm loosely arranged; scattered with more secretory cells, containing orange-yellow oil droplets; stone cells occasionally visible. Phloem relatively broad, secretory cells less. Cambium in a ring. Xylem rays broad, vessels sparse, arranged radially.

Powder: Dark brown Cork cells pale brown Parenchymratous cells subrounded, containing subrounded nuclei Secretory cells mostly similar to ordinary parenchymatous cells in shape, containing orange or orange-red oil droplets. Bordered pitted and reticulated vessels up to about 92 μm in diameter.

(2) To 2 g of the powder add 20 ml of methanol. heat under reflux on a water bath for 1 hour, cool, filter, concentrate the filtrate to 5 ml used as the test solution. Dissolve catalpol CRS in methanol to produce a solution containing 0.5 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 chloroform, methanol and water (14 : 6 : 1) as the mobile phase. Apply separately 5 μl of each of the above two solutions to the plate. After developing and removal of the plate, dry in air, spray with anisaldehyde TS, beat at 105℃ to the spots clear. A spot in the chromatogram obtained with the test solution corresponds in colour and position to spot in the chromatogram ohtained with the reference solution.

(3) To 1 g of the powder add 50 ml of 80% methanol, ultrasonicate for 30 minutes, filter. Evaporate the filtrate to dryness, dissolve the residue in 5 ml of water. Extract by shaking with four 10-ml quantities of n-butanol saturated with water, combine the n-butanol solutions, evaporate to dryness, dissolve the residue in 2 ml of methanol as the test solution. Dissolve a quantity of verbascoside CRS in methanol to produce a solution containing 1 mg per ml as the reference solution. Carry out the method for thin layer chromatography <0502>, using siica gel G as the coating substance and a mixture of ethyl acetate, methanol and formic acid (16 : 0.5 : 2) as the mobile phase. Apply separately 5 μl of the test solution and 2 μl of the reference solution to the plate. After developing and removal of the plate, dry in air. Soak the plate briefly in a 0.1% solution of 2, 2-diphenyl-1-picrylhydrazyl in dehydrated ethanol, take out and dry in air. The spot in the chromatogram obtained with the test solution corresponds in position and colour to the spot in the chromatogram obtained with the reference solution.

Examination

Water

不得过15.0%（通则0832第二法）。

Total ash

Not more than 8.0 per cent <2302>.

Acid-insoluble ash

Not more than 3.0 per cent <2302>.

Extractives

Carry out the method for determination of water extractives <2201, the cold maceration method >, not less than 65 0 per cent.

Assay

照高效液相色谱法（通则0512）测定。

以十八烷基硅烷键合硅胶为填充剂；以乙腈-0.1%磷酸溶液（1：99）为流动相；检测波长为210nm。理论板数按梓醇峰计算应不低于5000。

取梓醇对照品适量，精密称定，加流动相制成每1ml含10µg的溶液，即得。

取本品（生地黄）切成约5mm的小块，经80℃减压干燥24小时后，磨成粗粉，取约0.8g，精密称定，置具塞锥形瓶中，精密加入甲醇50ml，称定重量，加热回流提取1.5小时，放冷，再称定重量，用甲醇补足减失的重量，摇匀，滤过，精密量取续滤液10ml，浓缩至近干，残渣用流动相溶解，转移至10ml量瓶中，并用流动相稀释至刻度，摇匀，滤过，取续滤液，即得。

分别精密吸取对照品溶液与供试品溶液各10µ1，注入液相色谱仪，测定，即得。

It contains not less than 0.20 per cent of catalpol (C15H22O10), calculated with reference to the dried drug of sheng Dihuang.

照高效液相色谱法（通则0512）测定。

以十八烷基硅烷键合硅胶为填充剂；以乙腈-0.1%醋酸溶液（16：84）为流动相；检测波长为334nm。理论扳数按毛蕊花糖苷峰计算应不低于5000。

取毛蕊花糖苷对照品适量，精密称定，加流动相制成每1ml含10µg的溶液，即得。

精密量取〔含量测定〕项梓醇项下续滤液20ml，减压回收溶剂近干，残渣用流动相溶解，转移至5ml量瓶中，加流动相至刻度，摇匀，滤过，取续滤液，即得。

分别精密吸取对照品溶液与供试品溶液各20µl，注入液相色谱仪，测定，即得。

It contains not less than 0.020 per cent of verbascoside (C29H36O15), calculated with reference to the dried drug of Sheng Dihuang.##饮片 | Prepared slices

Rehmanniae Radix

Processing

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

Property

Cold.

Flavor

Sweet and bitter.

Meridian tropism

Fresh Rehmanniae Radix: Heart, liver and kidney meridians.

Unprocessed Rehmanniae Radix: Heart, liver and kidney meridians.

Actions

Fresh Rehmanniae Radix: To clear heat, engender fluid, cool the blood, and stop bleeding.

Unprocessed Rehmanniae Radix: Clear heat, cool the blood, nourish yin, and engender fluids.

Indications

Fresh Rehmanniae Radix: Febrile disease damaging yin, crimson tongue, vexation, thirst, macula and papule caused by warm toxin, hematemesis, epistaxis, and swelling and sore throat.

Unprocessed Rehmanniae Radix: Heat entering nutrient-blood aspects, macula and papule caused by warm toxin, hematemesis damaging yin, crimson tongue, vexation, thirst, fluid consumption, yin deficiency fever, steaming bone, consumptive fever, interior heat, and wasting-thirst.

Dosage

Fresh Rehmanniae Radix: 12-30 g.

Unprocessed Rehmanniae Radix: 10-15 g.

Administration

Add when the decoction is nearly done.

Storage

Fresh Rehmannia Root is embedded in sand and protected from freezing; unprocessed Rehmanniae Root is preserved in a ventilated dry place and protected from mold and moth.