Endo-fenchyl acetate rich essential oil of Strobilanthes sessilis Nees inflorescence and its characterisation using GC, GC-MS, and NMR techniques.

Strobilanthes Blume is a genus in the family Acanthaceae, with many species endemic to the Indian subcontinent. Strobilanthes sessilis Nees is endemic to the southern Western Ghats of India. The essential oil of dried inflorescence of S. sessilis was extracted using hydrodistillation method and the chemical composition was determined using GC and GC-MS techniques, which revealed the major compound to be endo-fenchyl acetate (89.33%). Other minor compounds like endo-fenchol (3.74%), (E)-caryophyllene (1.07%), and limonene and ß-phellandrene (0.55%) were also observed. The major diastereomer of fenchyl acetate was determined using 2D-NMR techniques like HSQC, HMBC, and ROESY to confirm the endo configuration. The optical rotation of the oil in different solvents deduced that the laevorotatory enantiomer of endo-fenchyl acetate as the major or single compound. S. sessilis could be further explored as a major source of endo-fenchyl acetate, which has high importance in flavouring and other biological applications.

Molecular docking and dynamics simulation study of quinones and pyrones from Alternaria solani and Alternaria alternata with HSP90: an important therapeutic target of cancer.

Although cancer continues to be one of the world's major causes of death, current cancer drugs have many serious side effects. There remains a need for new anticancer agents to overcome these shortcomings. Alternaria is one of the most widespread fungal genera, many species of which produce several classes of metabolites with potential polypharmacological activities. A few quinones and pyrones from Alternaria spp. have proven to exert cytotoxic effects against certain cancer cell lines, but their molecular mode of action is not known. The current study aimed to investigate the potential mechanisms that underlie the anticancer activity of a few selected quinones and pyrones from Alternaria solani and Alternaria alternata by molecular docking and dynamic simulation approaches. The selected metabolites were screened for their binding affinity to Heat shock protein 90 (HSP90), which is a known anticancer drug target. Molecular docking studies have revealed that Macrosporin, Altersolanol B, Fonsecin, and Neoaltenuene have good binding affinities with the target protein and the stabilities of the formed complexes were evaluated through molecular dynamics simulations. By analyzing the Root Mean Square Distance (RMSD), Root Mean Square Fluctuation (RMSF), and Principal Component Analysis (PCA) plots obtained from molecular dynamics simulations, this study shows that the complexes of all 4 lead molecules with target protein are stable over a 100 ns period. Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) calculations were used to compute the binding free energies. The lead molecules were studied using in-silico analysis to determine their drug-likeness based on their Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) and physicochemical properties. The results demonstrate that Macrosporin, Fonsecin, and Neoaltenuene could become promising anticancer molecules that target HSP90.Communicated by Ramaswamy H. Sarma.