On Aethina Erichson of Northeast India (Coleoptera: Nitidulidae: Nitidulinae).

Four species of Aethina [Aethina (Aethina) vicina Grouvelle, 1894, Aethina (Idaethina) orientalis (Nietner, 1856), Aethina (Idaethina) subrugosa (Grouvelle, 1894b) and Aethina (Circopes) subquadrata (Motschulsky, 1858)] have been newly recorded from northeast Indian states. Hitherto, three species, viz., Aethina (Aethina) argus Grouvelle, 1890, Aethina (Aethina) cyaneipennis Grouvelle, 1903 and Aethina (Aethina) inconspicua Nakane, 1967 were known from Northeast India. The specific status of Aethina (Aethina) nigrocastanea Grouvelle, 1903 has been reestablished. Altogether eight species of Aethina are treated in this paper. The paper incorporates redescriptions of the genus, and species of Aethina from Northeast India with a key to these species.

Computational and experimental insight into antituberculosis agent, (E)-benzyl-2-(4-hydroxy-2-methoxybenzylidene) hydrazinecarbodithioate: ADME analysis.

A new Schiff base, (E)-benzyl-2-(4-hydroxy-2-methoxybenzylidene)hydrazinecarbodithioate (compound 1) has been synthesized and experimentally characterized by the IR, UV-Vis, 1H-NMR and mass spectroscopies. The theoretical study of the synthesized compound was evaluated using the density functional theory (DFT) at B3LYP/6-31G+(d,p) basis set. The electronic absorption spectrum of compound 1 was evaluated using time-dependent density functional theory. Besides, in silico studies were done for the prediction of absorption, distribution, metabolism and excretion profiles of compound 1. According to the result, the theoretical data were well fitted with the experimental values. The studied compound has low chemical reactivity and high kinetic stability. In the molecular electrostatic potential map, the negative and positive potential sites were found around electronegative atoms and hydrogen atoms of compound 1, respectively. The 97.75% Lewis and 2.25% non-Lewis structure were present in the studied molecule. The molecular docking results reveal that compound 1 can be used as antituberculosis agent as compare to ethambutol.

DFT studies on vibrational and electronic spectra, HOMO-LUMO, MEP, HOMA, NBO and molecular docking analysis of benzyl-3-N-(2,4,5-trimethoxyphenylmethylene)hydrazinecarbodithioate.

Benzyl-3-N-(2,4,5-trimethoxyphenylmethylene)hydrazinecarbodithioate (compound 1) is a bidentate and nitrogen-sulfur containing Schiff base, which has been synthesized by the condensation reaction of S-benzylndithiocarbazate and 2,4,5-trimethoxybenzaldehyde. The theoretical calculations of the mentioned compound have been carried out using the more popular density functional theory method, Becke-3-Parameter-Lee-Yang-Parr (B3LYP) in 6-31G+(d,p) basis set. The computational results of the compound were compared with the obtained experimental value. Moreover, the highest occupied molecular orbital, the lowest unoccupied molecular orbital, molecular electrostatic potential, chemical reactivity parameters and natural bond orbital of the optimized structure have been evaluated at the same level of theory. Furthermore, the UV-Vis spectrum of the compound has been carried out for the better understanding of electronic absorption spectra with the help of the time-dependent density functional theory at room temperature. Besides, the molecular docking simulation of the mentioned molecule with target protein was also investigated. In addition, in silico studies were performed to predict absorption, distribution, metabolism, excretion and toxicity profiles of the designed compound. The results indicated that the theoretical data have well correlated with the observed values. The narrow frontier orbital gap indicated that the eventual charge transfer interaction occurs within the studied molecule and showed high chemical reactivity. The global reactivity values showed that the compound is soft molecule, electrophilic species and has strong binding ability with biomolecules. The molecular electrostatic potential structure indicated that the negative and positive potential sites are around electronegative atoms and hydrogen atoms of studied compound, respectively. The natural bond orbital data revealed that the compound contains 97.42% Lewis and 2.58% non-Lewis structure. The intra and inter-molecular charge transfers process occur within the studied compound. The studied compound showed more binding energy (-6.0 kcal/mol) with target protein than hydroxychloroquine (-5.6 kcal/mol). The absorption, distribution, metabolism, excretion and toxicity investigation predicted that the compound has good drug like character.

A general route to mono- and disubstituted divinyl sulfones: acyclic Michael acceptors for the synthesis of polyfunctionalized cyclic sulfones.

Nucleophilic C-S bond formation using easily available ß-hydroxysulfonate derivatives allowed direct access to new mono- and disubstituted divinyl sulfones. Our strategy uses thioethanol (HSCH(2)CH(2)OH) and its analogues such as HSCH(2)CH(Y)OH generated in situ. The strategy also allows the synthesis of modified divinyl sulfones attached to chiral appendages like carbohydrates. Bis-heteronucleophilic Michael addition reactions with 1 equiv of a primary amine afforded new generations of S,S-dioxothiomorpholine derivatives known for their therapeutic applications. Further synthetic manipulations of some of these cyclic compounds led to the synthesis of novel bicyclic derivatives.

First synthesis and antiprotozoal activities of divinyl sulfone-modified carbohydrates.

Divinyl sulfone-modified carbohydrates have been synthesized for the first time by reacting easily available carbohydrate epoxides with thioethanol in a regiospecific fashion. One of the modified divinyl sulfones initiated significant cell death in Entamoeba species and the influence of the anomeric configurations on the biological activities of these sugar-derived divinyl sulfones has been highlighted. The most active compound in this series was found to be devoid of any toxicity.

A surprising C-4 epimerization of 5-deoxy-5-sulfonylated pentofuranosides under Ramberg-Bäcklund reaction conditions.

Treatment of methyl 5-deoxy-2,3-O-isopropylidene-5-(benzylsulfonyl)-ß-D-ribofuranoside with CBr(2)F(2)-KOH/Al(2)O(3) afforded the corresponding olefinic sugar. The methyl- and the isopropyl-analogues in contrast underwent epimerization at C-4 to generate the α-L-lyxo derivatives.