Binding and molecular dynamic studies of sesquiterpenes (2R-acetoxymethyl-1,3,3-trimethyl-4t-(3-methyl-2-buten-1-yl)-1t-cyclohexanol) derived from marine Streptomyces sp. VITJS8 as potential anticancer agent

• Published in: Applied microbiology and biotechnology 2016-03, Vol.100 (6), p.2869-2882
• Main Authors: Naine, S. Jemimah, Devi, C. Subathra, Mohanasrinivasan, V, Doss, C. George Priya, Kumar, D. Thirumal
• Format: Article
• Language: English
• Subjects: absorption; active ingredients; Antibiotics; antineoplastic agents; Antineoplastic Agents - chemistry; Antineoplastic Agents - metabolism; antioxidant activity; Apoptosis; Biomedical and Life Sciences; Biotechnology; Cancer therapies; Cell cycle; Cell Proliferation - drug effects; Cell Survival - drug effects; Chemotherapy; Chromatography; Chromatography, Liquid; Cluster Analysis; Cytotoxicity; Deoxyribonucleic acid; DNA; DNA fragmentation; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Drug development; Drugs; energy; Environmental Biotechnology; Environmental Microbiology; flow cytometry; Gas chromatography; Gas Chromatography-Mass Spectrometry; Genetic engineering; Hep G2 Cells; high performance liquid chromatography; human cell lines; Humans; Inhibitory Concentration 50; Life Sciences; Ligands; Liquid chromatography; Mass spectrometry; Medical research; Metabolites; Microbial Genetics and Genomics; Microbiology; Molecular Dynamics Simulation; molecular models; Molecular Sequence Data; Molecular Structure; Morphology; Natural products; pathogens; Pharmaceutical industry; Phylogenetics; Phylogeny; Retention; Retention time; RNA, Ribosomal, 16S - genetics; sequence analysis; Sequence Analysis, DNA; Sesquiterpenes - chemistry; Sesquiterpenes - metabolism; sesquiterpenoids; Simulation; Simulation analysis; spectral analysis; Streptomyces; Streptomyces - classification; Streptomyces - genetics; Streptomyces - isolation & purification; Streptomyces - metabolism; Studies
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-015-7156-2

The main aim of the current study is to explore the bioactive potential of Streptomyces sp. VITJS8 isolated from the marine saltern. The cultural, biochemical, and morphological studies were performed to acquire the characteristic features of the potent isolate VITJS8. The 16Sr DNA sequencing was performed to investigate the phylogenetic relationship between the Streptomyces genera. The structure of the compound was elucidated by gas chromatography-mass spectrometry (GC-MS), infra-red (IR), and ultra-violet (UV) spectroscopic data analysis. The GC-MS showed the retention time at 22.39 with a single peak indicating the purity of the active compound, and the molecular formula was established as C₁₄H₉ONCl₂ based on the peak at m/z 277 [M]⁺. Furthermore, separated by high-performance liquid chromatography (HPLC), their retention time (t ᵣ) 2.761 was observed with the absorption maxima at 310 nm. The active compound showed effective inhibitory potential against four clinical pathogens at 500 μg/mL. The antioxidant activity was found effective at the IC₅₀ value of 500 μg/mL with 90 % inhibition. The 3-(4,5-dimethylthiazol-2-yl)-2,5-ditetrazolium bromide (MTT) assay revealed the cytotoxicity against HepG2 cells at IC₅₀ of 250 μg/mL. The progression of apoptosis was evidenced by morphological changes by nuclear staining. The DNA fragmentation pattern was observed at 250 μg/mL concentration. Based on flow cytometric analysis, it was evident that the compound was effective in inhibiting the sub-G0/G1 phase of cell cycle. The in vitro findings were also supported by the binding mode molecular docking studies. The active compound revealed minimum binding energy of −7.84 and showed good affinity towards the active region of topoisomerase-2α that could be considered as a suitable inhibitor. Lastly, we performed 30 ns molecular dynamic simulation analysis using GROMACS to aid in better designing of anticancer drugs. Simulation result of root mean square deviation (RMSD) analysis showed that protein-ligand complex reaches equilibration state around 10 ns that illustrates the docked complex is stable. We propose the possible mechanism of sesquiterpenes to play a significant role in antitumor cascade. Hence, our studies open up a new facet for a potent drug as an anticancer agent.