Bioconversion of lovastatin to a novel statin by Amycolatopsis sp

Comparison of the elution characteristics of individual forms of lovastatin in both isocratic and gradient modes and HPLC-PDA method development for pure and fermentation-derived lovastatin

The elution characteristics of lovastatin were studied by varying the composition of mobile phase in both isocratic and gradient elution modes to comprehend the role of organic modifier and acidifier on the overall analysis time and retention time of individual forms of lovastatin. Acetonitrile has influenced on the overall analysis time, whereas the acidifier determines the retention time of hydroxy acid form of lovastatin and the retention time gap between the individual forms. A combination of acetonitrile and 0.1% trifluoroacetic acid (TFA) (60:40, v/v) in isocratic elution mode eluted both hydroxy acid and lactone forms of lovastatin at 4.5 and 5.4 min, respectively. This appears to be a better approach for the separation of pharmaceutical and clinical lovastatin samples. At isocratic elution mode, a mixture of acetonitrile and either 0.05% TFA or 0.1% H₃PO₄ of 60:40 (v/v) has eluted both hydroxy acid and lactone forms of lovastatin at 10 ± 0.5 and 17 ± 0.5 min, respectively. This is suitable for the fermentation-derived samples or for the complex mixtures of structural analogs. The fermentation broth (pH not adjusted) extracted with ethyl acetate at a ratio of 1:1 (v/v) at 60°C for 30 min was the optimal extraction condition for lovastatin.

Characterization of a novel cytochrome P450 from Amycolatopsis sp. CGMCC1149 for hydroxylation of lovastatin

Wuxistatin, a novel and potent statin, is converted from lovastatin by Amycolatopsis sp. CGMCC1149. In the bioconversion, lovastatin is firstly hydroxylated to 3-hydroxymethyl lovastatin (product I) by a hydroxylase. In the current study, a novel hydroxylase gene p450lov was isolated from Amycolatopsis sp. CGMCC1149 by degenerate PCR and self-formed adaptor PCR and expressed in Escherichia coli. The gene encodes a 403-amino-acid protein with a molecular weight of 44.8 kDa and was designated as a new member of cytochrome P450 (CYP) 105 family, CYP105A44. Meanwhile, a lovastatin catalytic in vitro system was established, and an optimal hydroxylation reaction system contained 30 µM lovastatin, 600 µM NADH, 120 µM ferredoxin, 0.04 U ferredoxin-nicotinamide adenine dinucleotide phosphate reductase, and 100 µM CYP105A44 in a final volume of 200 µL Tris HCl buffer (50 mM, pH 7.4). These would be helpful for further studies on the hydroxylation of statins.

Current biotechnological applications of the genus Amycolatopsis

Recently there has been increasing interest in possible biotechnological applications of the bacterial genus Amycolatopsis. This genus originally attracted attention for its antibiotic producing capabilities; although it is actually a multifaceted genus and a more diverse range of studies involving biotechnological processes have now been undertaken. Several works have demonstrated that the versatility shown by these bacteria is valuable in industrial applications. Here, we provide a condensed overview of the most important biotechnological applications such as bioremediation, biodegradation and bioconversion, as well as aspects that need to be explored further in order to gain a fuller insight into this genus, including its possible potential in the production of biofuel. Antibiotic production is not discussed since this is well covered by the latest edition of Bergey's Manual of Systematic Bacteriology. To our knowledge this is the first report highlighting the versatility and biotechnological potential of the genus Amycolatopsis.

Advances in the bioconversion mechanism of lovastatin to wuxistatin by Amycolatopsis sp. CGMCC 1149

Wuxistatin, a novel statin and more potent than lovastatin, was converted from lovastatin by Amycolatopsis sp. (CGMCC 1149). Product I, an intermediate product, was found in the fermentation broth, and the structure analysis showed that product I had an additional hydroxyl group at the methyl group attached to C3 compared to lovastatin, which indicates that product I is one isomer of wuxistatin. Isotope tracing experiment proved that hydroxyl group of wuxistatin was provided by product I and the reaction from product I to wuxistatin was an intramolecular transfer. Hydroxylation reaction established in a cell-free system could be inhibited by CO and enhanced by ATP, Fe(2+), and ascorbic acid, which were consistent with the presumption that the hydroxylase was an induced cytochrome P450. Study on proteomics of Amycolatopsis sp. CGMCC 1149 suggested that three identified proteins, including integral membrane protein, Fe-S oxidoreductase, and GTP-binding protein YchF, were induced by lovastatin and required during hydroxylation reaction. In conclusion, bioconversion mechanism of wuxistatin by Amycolatopsis sp. CGMCC 1149 was proposed: lovastatin is firstly hydroxylated to product I by a hydroxylase, namely cytochrome P450, and then product I is rearranged to wuxistatin by isomerases.

Novel Pyridinium compound from marine actinomycete, Amycolatopsis alba var. nov. DVR D4 showing antimicrobial and cytotoxic activities in vitro

Marine sediment samples from Visakhapatnam coast of Bay of Bengal, India, were investigated as a source of actinomycetes to screen for the production of antibiotics and cytotoxic compounds. Actinomycete strain DVR D4 with interesting bioactivity profile was isolated during our systematic study of marine actinomycetes. Based on biochemical properties and 16S rDNA analysis the isolate DVR D4 was identified as a strain of Amycolatopsis alba. A solvent extraction followed by a chromatographic purification helped to isolate a cytotoxic compound, which was identified as 1(10-aminodecyl) Pyridinium salt antibiotic, on the basis of spectral data. The compound showed potent cytotoxic activity against cancer cell lines of cervix (HeLa), breast (MCF-7) and brain (U87MG) in vitro and also exhibited antibacterial activities against Gram-positive and Gram-negative bacteria.