大青叶
中文文本参考：《中国药典（2020年版）》
English text reference: Chinese Pharmacopoeia (2020 Edition)
大青叶DaqingyeIsatisis FoliumIsatis Leaf
概述 Overview
本品为十字花科植物菘蓝Isatis indigotica Fort.的干燥叶。夏、秋二季分2～3次采收，除去杂质，晒干。
Isatis Leaf is the dried leaf of Isatis indigotica Fort. (Fam. Cruciferae). The drug is collected 2-3 times in summer and autumn, removed from impurities, and dried.
性状 Description
本品多皱缩卷曲，有的破碎。完整叶片展平后呈长椭圆形至长圆状倒披针形，长5～20 cm，宽2～6 cm；上表面暗灰绿色，有的可见色较深稍突起的小点；先端钝，全缘或微波状，基部狭窄下延至叶柄呈翼状；叶柄长4～10 cm，淡棕黄色。质脆。气微，味微酸、苦、涩。
The drug is mostly wrinkled, curled, and some are broken. The whole leaf, when flattened, is elongated-elliptical to elongated-lanceolate, 5-20 cm long, 2-6 cm wide; upper surface dark grayish-green, some with slightly darker raised dots; apex obtuse, entire or slightly undulate, base narrowly extended downward to form a wing-like shape on the petiole; petiole 4-10 cm long, pale brownish-yellow. Texture, brittle. Odour, slight; taste, slightly sour, bitter, and astringent.
鉴别 Identification
（1）本品粉末绿褐色。下表皮细胞垂周壁稍弯曲，略成连珠状增厚；气孔不等式，副卫细胞3～4个。叶肉组织分化不明显；叶肉细胞中含蓝色细小颗粒状物，亦含橙皮苷样结晶。
(1) The powder is greenish-brown. The periclinal walls of the lower epidermal cells are slightly curved and slightly thickened in a chain-like manner; the stomata are unequal, with 3-4 subsidiary cells. Differentiation of mesophyll tissue is not obvious; mesophyll cells contain blue fine granules and also contain hesperidin-like crystals.
（2）取本品粉末0.5 g，加三氯甲烷20 ml，加热回流1小时，滤过，滤液浓缩至1 ml，作为供试品溶液。另取靛蓝对照品、靛玉红对照品，加三氯甲烷制成每1 ml各含1 mg的混合溶液，作为对照品溶液。照薄层色谱法（通则0502）试验，吸取上述两种溶液各5 μl，分别点于同一硅胶G薄层板上，以环己烷-三氯甲烷-丙酮（5:4:2）为展开剂，展开，取出，晾干。供试品色谱中，在与对照品色谱相应的位置上，分别显相同的蓝色斑点和浅紫红色斑点。
(2) Take 0.5 g of the powder, add 20 ml of chloroform, heat under reflux for 1 hour, filter, concentrate the filtrate to 1ml as the test solution. Take separately indigo blue reference substance and indigo carmine reference substance, add chloroform to make a mixed 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 cyclohexane-chloroform-acetone (5:4:2) 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. The test solution exhibits blue spots and light purple-red spots at the corresponding positions in the chromatogram obtained with the reference solution.
检查 Examination
水分 Water
不得过13.0%（通则0832第二法）。
Not more than 13.0 per cent <0832,method 2>.
浸出物 Extractives
照醇溶性浸出物测定法（通则2201）项下的热浸法测定，用乙醇作溶剂，不得少于16.0%。
Carry out the method for determination of ethanol-soluble Extractives <2201,the hot maceration method>, using ethanol as the solvent,not less than 16.0 per cent.
含量测定 Content determination
照高效液相色谱法（通则0512）测定。
Carry out the determination by high performance liquid chromatography <0512>.
色谱条件与系统适用性试验 Chromatographic conditions and system suitability test
以十八烷基硅烷键合硅胶为填充剂；以甲醇-水（75∶25）为流动相；检测波长为289 nm。 理论板数按靛玉红峰计算应不低于4000。
Use octadecylsilane bonded silica gel as the filler; use methanol-water (75:25) as the mobile phase; detect at a wavelength of 289 nm. The theoretical plate number calculated according to the peak of indigo carmine should not be less than 4000.
对照品溶液的制备 Preparation of reference solution
取靛玉红对照品适量，精密称定，加甲醇制成每1 ml含2 μg的溶液，即得。
Take an appropriate amount of indigo carmine reference substance, accurately weigh, add methanol to make a solution containing 2 μg per ml, and set aside.
供试品溶液的制备 Preparation of test solution
取本品细粉0.25 g，精密称定，置索氏提取器中，加三氯甲烷，浸泡15小时，加热回流提取至提取液无色。回收溶剂至干，残渣加甲醇使溶解并转移至100 ml 量瓶中，加甲醇至刻度，摇匀，滤过，取续滤液，即得。
Take 0.25 g of the powdered sample, accurately weigh, place it in a Soxhlet extractor, add chloroform, soak for 15 hours, heat and reflux until the extract is colorless. Recover the solvent to dryness, dissolve the residue in methanol and transfer it to a 100 ml volumetric flask, add methanol to the mark, shake well, filter, and take the filtrate.
测定法 Determination method
分别精密吸取对照品溶液与供试品溶液各20 μl，注入液相色谱仪，测定，即得。
Precisely draw 20 μl of the reference solution and the test solution, inject them into the liquid chromatograph, and determine the content.
本品按干燥品计算，含靛玉红（C16H10N2O2）不得少于0.020%。
Calculate this product based on the dried product, and the content of indigo carmine (C16H10N2O2) should not be less than 0.020%.
饮片 Prepared slices
大青叶 Isatis Leaf
炮制 Processing
除去杂质，抢水洗，切碎，干燥。
Eliminate Foreign matter, wash quickly with Water, cut into pieces, and dry in the sun.
性状 Description
本品为不规则的碎段。叶片暗灰绿色，叶上表面有的可见色较深稍突起的小点；叶柄碎片淡棕黄色。质脆。 气微，味微酸、苦、涩。
This product is irregularly broken segments. Leaf blade dark grey-green, some visible darker slightly raised dots on the upper surface of the leaf; petiole fragments pale brownish yellow. The texture is brittle. Slightly sour, bitter, astringent taste.
检查 Examination
水分 Water
同药材，不得过10.0%。
Same as the medicinal material, not more than 10.0 per cent.
鉴别 Identification
同药材。
Same as the medicinal material.
浸出物 Extractives
同药材。
Same as the medicinal material.
含量测定 Content determination
同药材。
Same as the medicinal material.
性 Property
寒。
Cold.
味 Flavor
苦。
Bitter.
归经 Meridian tropism
归心、胃经。
Belongs to the heart and stomach meridians.
功能 Actions
清热解毒，凉血消斑。
To clear heat and detoxify, cool blood and eliminate spots.
主治 Indications
用于温病高热，神昏，发斑发疹，痄腮，喉痹，丹毒，痈肿。
Used for high fever in warm diseases, coma, eruption of spots, mumps, throat obstruction, erysipelas, and carbuncle.
用量 Dosage
9～15 g。
9-15 g.
用法 Administration
无。
None.
贮藏 Storage
置通风干燥处，防霉。
Store in a well-ventilated and dry place, and prevent mold.
