Biotransformation of Panax notoginseng by fungi
Abstract
Roots of Panaxnotoginseng were fermented with 30 fungi respectively. Almost one -third of the products showed increasing antibacterial activity. All products could inhibit GST-CDC25 phosphatase as a potential antitumor agent. HPLC profiles proved that components of unfermented P. notoginseng and fermented P. notoginseng have obviously changes .
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Introduction
Panax notoginseng (Sanqi) is a famous traditional Chinese herb. It has obvious functions such as promot ing blood circulation, preventing the formation of blood clots, dissolving blood clots, and removing cellular breakdown products or other debris from the blood circulation (Jiang 1995, Li 1999). Microbial fermentation has been used from ancient times in TCM preparation. Microorganisms possess abundant enzyme systems and have strong ability for transforming. The TCM fermented by the microbe may produce new active metabolites, accumulate amount of active components, or modify the structure of existed compound s to be useful. There were few reports to be found concerning the fermentation of P. notoginseng . Liet al. (2000) has tried to transform ginsenoside Rb1 and Rg1 by pathogenic microbes Pseudomones spp. and Fusarium spp. to find what occurred after pathogen y. No obvious transformation was observed at the end. Li et a l. (2003) reported that Sanqi was fermented by Bacillus subtilis . An antitumor compound ginsenodide Rh4 was isolated from the fermentation products, and two saponins, ginsenosides Rh1 and Re had been linked with one more glucosyl moiety. The transformed product of ginsenoside Rh1 was determined to be a new compound as 3-O-β-D-glucopyranosyl -6-O-β-D- glucopyranosyl -20(S) -protopanaxatriol, which was linked with twoβ -D-glucopyranosyls at C -3 and C -6 in the meantime.
In our study, we found that P. notoginseng fermented by different fungi showed antibacterial and antitumor ac tivities. It provided us the chance to explore what happened in that processes and the possibility to find new active compounds.
Conclusion
Microbes have significant ability in transformation. Enzymatically -based transformations belong in the standard toolbox of the organic chemist. As many techniques and biocatalysts are now readily available, the field continues to grow steadily by means of many new and exciting developments that have taken place in the past few years. In our study, we tried to use these skills to transform P. notoginsneg , a famous Chinese herb. The results proved that it is a useful way to explore new functions of traditional herbs.
Comparing with unfermented P. notoginseng , antibacterial and antitumor activity was produced. Because different species have different enzyme systems, it can explain only parts of why transforming products have changes in activity. During the fermented process of P. notoginseng , there are various situations. One is that new active metabolites were produced in fungi metabolism, in which components of P. notoginseng work as formers. The other reason is that trace active compounds in P. notoginseng are accumulated by fungus in the fermenting process, so obviously activity is presented. The third is that components of P. notoginseng act as inducers leading to an uncommon enzyme system start up, then new metabolites and new activity was emerged. In fact, our results illustrated in Figure 1 proved that some new components were produced after fermentation. But such hypothesizes need to be proved by further study. We need to determ ine what indeed happened between fungi and P. notoginseng .
