Bioconversion of lovastatin to simvastatin by Streptomyces carpaticus toward the inhibition of HMG-CoA activity.

The aim of this study was the modification of lovastatin by microbes to improve its potential. Actinobacteria exhibit staggering diversity in terms of their biosynthetic capability for specialized metabolites which has been traced back to the presence of specialized gene clusters. The objective of the study is to exploit the potential of Actinobacteria strain(s), which can biotransform lovastatin to simvastatin, which might be a more potent therapeutic agent than lovastatin. We have screened 40 Actinobacteria strains and assessed their biotransformation potential primarily through thin layer chromatography (TLC) analysis, followed by high performance thin layer chromatography and high performance liquid chromatography analysis. One strain C7 (CTL S12) has been identified as a potential Actinobacteria that favored the simvastatin biotransformation. The morphological and biochemical analysis together with 16S rRNA sequencing coupled with phylogenetic analysis confirmed the ideal strain (C7) as Streptomyces carpaticus. Successively, the purified simvastatin from S. carpaticus was characterized by liquid chromatography-mass spectrometry (LC-MS), infrared spectrometry, nuclear magnetic resonance, and HMG-CoA assay. In the LC-MS analysis, a peak at 419.24 m/z confirmed the elemental composition of simvastatin (C25 H39 O5 ). In HMG-CoA assay, the IC50 of simvastatin was 50 µg/ml, and the inhibitory potential was 1.36 times higher compared to that of lovastatin. Thus, the biotransformation of simvastatin from lovastatin by S. carpaticus is reported for the first time.

Bioprospecting lovastatin production from a novel producer Cunninghamella blakesleeana.

Beside anti-cholesterol activity, lovastatin garners worldwide attention for therapeutical application against various diseases especially cancer. A total of 36 filamentous fungi from soil samples were isolated and screened for lovastatin production by yeast growth bioassay method. C9 strain (later identified as Cunninghamella blakesleeana) was screened as potential strain of lovastatin production. Further confirmation of the compound was made using TLC, HPTLC and HPLC in which similar Rf value, densitogram peak and chromatogram peak against the standard lovastatin were observed, respectively. The purified lovastatin subjected for IR analysis showed a lactone ring peak at 1763.63 cm-1 similar to standard lovastatin. Further structural analysis including NMR and LC-MS of the purified lovastatin reassures the molecular formula and molecular weight similar to standard. In quantitative terms, C. blakesleeana, Aspergillus terreus and Aspergillus flavus produced 1.4 mg g-1 DWS, 0.83 mg g-1 DWS and 0.3 mg g-1 DWS of lovastatin, respectively, (p < 0.0001) without any optimization. Lovastatin showed significant antioxidant property with IC50: 145.9 µg mL-1 (140 µL), and the percentage of inhibition is maximum at 199.5 µg/mL which is statistically significant (p < 0.0001).