Potential of Lichen Secondary Metabolites against Plasmodium Liver Stage Parasites with FAS-II as the Potential Target
JOURNAL OF NATURAL PRODUCTS
Authors: Lauinger, Ina L.; Vivas, Livia; Perozzo, Remo; Stairiker, Christopher; Tarun, Alice; Zloh, Mire; Zhang, Xujie; Xu, Hua; Tonge, Peter J.; Franzblau, Scott G.; Duc-Hung Pham; Esguerra, Camila V.; Crawford, Alexander D.; Maes, Louis; Tasdemir, Deniz
Chemicals targeting the liver stage (LS) of the malaria parasite are useful for causal prophylaxis of malaria. In this study, four lichen metabolites, evernic acid (1); vulpic acid (2), psoromic acid (3), and, (+)-usnic acid (4), were evaluated against LS parasites of Plasmodium berghei. Inhibition Of P. falciparum blood Stage (BS) parasites was also assessed to determine stage specificity. Compound 4 displayed the highest LS activity and stage specificity (LS IC50 value 2.3 mu M, BS IC50 value 47.3 mu M). The compounds 1 - 3 inhibited one Or more enzymes (Pf FabI, PfFabG, and pfFabZ), from the Plasmodial fatty acid biosynthesis (FAS-II) pathway, a potential drug. target for LS activity. To determine species specificity and to clarify the mechanism of reported antibacterial effects, 1-4 were also evaluated against FabI homologues and Whole cells of various pathogens -(S. aureus, E. coli M. tuberculosis). Molecular modeling studies suggest that lichen acids act indirectly via binding to allosteric sites on the protein surface of the FAS-II enzymes. Potential. toxicity, of compounds was assessed in human hepatocyte and cancer cells (in vitro) as well as in a zebrafish model (in vivo):. This study indicates the therapeutic and prophylactic potential of lichen metabolites as antibacterial and antiplasmodial agents.,
Design, Synthesis and Biological Screening of Novel 1,3,4-Oxadiazoles as Antitubercular Agents
Authors: Tambe, Macchindra S.; Choudhari, Amit; Sarkar, Dhiman; Sangshetti, Jaiprakash; Patil, Rajesh; Gholap, Somnath S.
A series of novel 2,5-disubstitued 1,3,4-oxadiazole derivatives bearing 2,2-dimethyl-2,3-dihydrobenzofuran scaffold has been synthesized and screened for antitubercular activity. All the synthesized compounds were characterized by IR, H-1 NMR, C-13-NMR and Mass spectral study. The in vitro antitubercular activity of the synthesized compounds was evaluated against Mycobacterium tuberculosis H37Ra(ATCC 25177) strain. Among the synthesized compounds, four compound displayed good antitubercular activity IC50 values in low micro-gram range (<10 mu g/mL). The antitubercular data suggested that growth inhibition MTB can be imparted by the introduction of a 4- trifluoromethyl phenyl acetylene substituent. Specificity of these compounds was checked by screening them for their anti-bacterial activity against four bacterial strains (Gram-negative strains: E. coli, S. aureus; Gram-positive strains: P. aeruginosa and B. subtilis). None of the compound displayed antibacterial activity against any of the seleted strain. Molecular docking studies were carried out on InhA (FabI/ENR) which shows that the synthesized compounds bind at the catalytic site in a most favourable manner suggesting their potential as anti-mycobacterial agents. The research presented here was found to be adventitious for the development of new therapeutic agents against Mycobacterium infection.