Guangmutong is a traditional Chinese medicine that is harvested in the autumn and winter seasons. After removing the coarse skin and drying it, it has the effects of clearing heart fire, promoting urination, relieving menstrual pain, and promoting lactation. It is commonly used to treat oral ulcers, restlessness, red urine, and edema. But how do we identify Guangmutong?
Image of Guangmutong
Identification of Guangmutong
1. The powder of Guangmutong is pale yellow. The fiber cells are mostly bundled, long and polygonal, with a diameter of 11-20μm. The walls have obvious reticulate pores, which are slanted or intersected into a cross shape.
The diameter of the separated fibers is 21-42μm, and the oblique reticulate pores are obvious. Stone cells are rare, and they are square or polygonal with thick walls.
The size of calcium oxalate cluster crystals is about 40μm. The large reticulate pore ducts have a diameter of about 328μm, often fragmented, with reticulate pores arranged closely and few duct cells with reticulate pores.
2. Take 1g of the powder of Guangmutong, add 20ml of 70% ethanol, heat it reflux for 15 minutes, let it cool, and filter it.
Take a drop of the filtrate on filter paper and observe it under ultraviolet light (365nm). It shows a sky blue fluorescence when dry;
Add 1 drop of dilute hydrochloric acid to the spot, and it shows a yellow-green fluorescence when dry. After fumigation with ammonia vapor, it shows a sky blue fluorescence again.
3. Take 1g of the powder of Guangmutong, add 50ml of ethanol, heat it reflux for 1 hour, filter it, evaporate the filtrate, dissolve the residue with 1ml of ethanol, and use it as the test solution.
Image of Guangmutong
Take another 1g of Guangmutong as the reference material and make a solution following the same method. Take Aristolochic acid as the reference substance and make a solution containing 0.5mg per 1ml as the reference solution.
Use thin-layer chromatography (Appendix ⅥB) test. Take 3μl of each of the above three solutions and spot them on the same silica gel G thin-layer plate, making them in strip shape. Use the upper layer solution of toluene-acetic acid ethyl ester-water-formic acid (20:10:1: 1) as the developing agent, develop, take out, air dry, and examine under daylight and ultraviolet light (365nm).
In the test solution, there should be spots of the same color as the reference material and the reference substance in their corresponding positions.
Application of Guangmutong
1. Used to treat bladder damp-heat, short and red urine, and painful urination: Guangmutong is combined with Cheqianzi, Huashi, etc., as in the prescription Bazheng San (Compendium of Materia Medica).
2. Used to treat heart fire inflammation, oral ulcers, or restlessness and red urine caused by heart fire descending to the small intestine: Guangmutong is combined with Shengdi Huang, Gancao, Zhuye, etc., as in the prescription Daochi San (Direct Prescription for Pediatric Medicines).
Contraindications of Guangmutong
It should not be used excessively or for a long time, and it should be avoided in patients with renal insufficiency and pregnant women.
