Biotransformations of matrine and oxymatrine and the cholinesterase activity of metabolites

Microbial transformations are green biotechnological processes where different microorganisms or their enzymes are used to produce new metabolites from defined substrates. This technique has been utilized in chemical, food and pharmaceutical industries in recent years due to its advantages, also in pharmacognosy for the discovery and production of natural drugs. Matrine and oxymatrine are members of the quinolizidine alkaloids, which naturally occur in Sophora species known as "acı meyan" or "piyan" of the Fabaceae as secondary metabolites. In vitro and in vivo studies with matrine and oxymatrine on cardiac iscemia, viral symptoms and hepatitis B, anticancer, etc. are reported. In this present study, matrine and oxymatrine were subjected to microbial biotransformations by using 30 different bacteria, yeast, and fungi, respectively. The biotransformation of matrine by Mucor rammanianus and Enterococcus faecalis produced 2 new metabolites. in the isolation and characterization. Oxymatrine was biotransformed by 5 different microorganisms to produce matrine. The metabolites were intially identified by thin layer chromatography (TLC) and characterized by liquid chromatography/mass spectroscopy (LC/MS). Furthermore, the purified metabolites and substrates were subjected comparatively to in vitro antibacterial, anticandidal, anti-oxidant, antituberculosis evaluations and cholinesterase inhibition assays. All tested samples were not active at the tested concentrations and without significant inhibitory effects. Keywords: Matrine, oxymatrine, microbial transformation, antimicrobial activity, cholinesterase activity