A three dimensional Quantitative Structure Activity Relationship (3D-QSAR) model for a series of (S)-3-Aryl-5-substituted oxazolidinones was developed to gain insights into the design for potential new antibacterial agents. It was found that the Comparative Molecular Field Analysis (CoMFA) method yielded good results while the Comparative Molecular Similarity Indices Analysis (CoMSIA) was less satisfactory. The CoMFA method yielded a cross-validated correlation coefficient q(2) = 0.681, non-cross-validated R(2) = 0.991, SE (Standard Error ) = 0.054, and the value of statistical significance measure F = 266.98. The relative steric and electrostatic contributions are 0.542 and 0.458, respectively. These results indicate that the model possesses a high predictivity. Guided by this model, three new compounds were synthesized. All these compounds exhibit inhibitory activity; two of them were shown having high activity (MIC = 1.0 microg/ml). The activity observed by experiments was in good agreement with the theoretical one. It is anticipated that the present model would be of value in facilitating design of new potent antibacterial agents.

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Most recently, an outbreak of severe pneumonia caused by the infection of 2019-nCoV, a novel coronavirus first identified in Wuhan, China, imposes serious threats to public health. Upon infecting host cells, coronaviruses assemble a multi-subunit RNA-synthesis complex of viral non-structural proteins (nsp) responsible for the replication and transcription of the viral genome. Therefore, the role and inhibition of nsp12 are indispensable. Since there is no crystallographic structure of RdRp is available, so, here, we present the 3-dimensional structure of the 2019-nCoV nsp12 polymerase using a computational approach. nsp12 of 2019-nCoV possesses an architecture common to all viral polymerases as well as a large N-terminal extension. This structure illuminates the assembly of the coronavirus core RNA-synthesis machinery, provides key insights into nsp12 polymerase catalysis and fidelity, and acts as a template for the design of novel antiviral therapeutics. Besides, the experimental structure could reveal the organization in a more sophisticated way. Furthermore, the ancestral state reconstruction suggests the possible evolution of nCoV in Wuhan China and its dispersal to the USA. The result of our analyses postulates the possible dispersal of nCoV from the USA and Shenzhen back to Wuhan. This disclosing of valuable knowledge regarding the 3D structure of 2019-nCoV nsp12 architecture, ancestral relation, and dispersion pattern could help to design effective therapeutic candidates against the coronaviruses and design robust preventive measurements.

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Nicotinic acetylcholine receptors (nAChRs) are members of ligand gated ion channels (LGICs) which transduce chemical signal into electrical signal in neuron and neuromuscular junction. They are pentamerics which contain an extra-cellular domain (also known as ligand binding domain or LBD), a trans-membrane domain and a cytoplasmic domain (intra-cellular domain). Agonist binding to the extra-cellular domain invokes positive ion flux as well as action potential in neurons, muscle cells and endocrine cells whereas antagonist binding inhibits ion flux. There are various endogenous or exogenous compounds which behave as agonists or antagonists targeting nAChRs. During the last decades, the whole structure of muscle type nAChR as well as the crystal structures of acetylcholine-binding proteins (AChBPs) which are homologues of the nAChRs extra-cellular domain has been obtained. These structures, together with other studies including mutation experiments and molecular simulations, provide insights into both of the nAChR architecture and its agonist binding cavity. Our review gives detailed accounts of the recent progresses in order to gain insights into agonist selectivity for different nAChR subtypes.