Studies On Two Medicinal Sesquiterpene Lactones

Two medicinal sesquiterpene lactones, bilobalide and a-santonin, were isolated preparatively by means of extraction and column chromatography. Quantitative HPLC methods were set up to measure them respectively. Several factors were studied systemically such as linearity, repeatability, stability and recovery, which were coincidence with specifications. The purity of two sesquiterpene lactones were all more than 98%.The microbial biotransformation of a-santonin, a cytotoxic sesquiterpene lactone, had been investigated. Cunninghamella blakesleana AS3.970, a filamentous fungus, was screened from 11 fungal strains and able to convert a-santonin. Determining the products by HPLC showed that a-santonin was converted to 2 products, P1 and P2. P1 was separated and purified by extraction and silica gel column chromatography and identified as 11β-hydroxy-α-santonin on the basis of ¹H-NMR, ¹³C-NMR, HMBC, IR,UV and ESI-MASS spectral data.Pharmacological studies showed that bailobalide could improve memory disturbance induced by NaNO₂ in rats and protect rats against cerebral ischemic injury. Other studies performed using pheochromocytoma-derived PC12 and showed that treatment of PC12 with glutamate and KC1 markedly decreased cell viability, and that this cytotoxic effect was inhibited by bilobalide.