Single crystal of 14-dehydroxyl-13-dehydroandrographolide-12-potassium sulfonate and preparation method thereof

The invention discloses a single crystal of 14-dehydroxyl-13-dehydroandrographolide-12-potassium sulfonate as well as a preparation method and application of the single crystal, and belongs to the field of drug crystal form research. According to the invention, an acid-base reaction-crystallization coupling method is adopted to obtain the 14-dehydroxyl-13-dehydroandrographolide-12-potassium sulfonate single crystal; the chemical formula is C20H29KO7S, the crystal structure belongs to a monoclinic system, and the space group is P1 21 1, a = 7.2362 angstroms, b = 7.0368 angstroms, c = 21.2746 angstroms, alpha = 90 degrees, beta = 98.485 degrees, gamma = 90 degrees, V = 1071.43 angstroms and Z = 2. Compared with an effective component 14-dehydroxy-13- dehydroandrographolide-12-sodium sulfonate of a clinical medicine Lianbizhi, on the premise of the same anti-inflammatory effect, the product has the characteristics of low impurity content and almost no hygroscopicity, and is more suitable for preparation of a hig