Asymmetric counteranion-directed photoredox catalysis.

Photoredox catalysis enables distinctive and broadly applicable chemical reactions, but controlling their selectivity has proven to be difficult. The pursuit of enantioselectivity is a particularly daunting challenge, arguably because of the high energy of the activated radical (ion) intermediates, and previous approaches have invariably required pairing of the photoredox catalytic cycle with an additional activation mode for asymmetric induction. A potential solution for photoredox reactions proceeding via radical ions would be catalytic pairing with enantiopure counterions.

Post-transcriptional regulation of MMP2 mRNA by its interaction with miR-20a and Nucleolin in breast cancer cell lines.

Matrix-metalloproteinase-2 (MMP2) is a foremost MMP, governing invasion of breast cancer cells during metastasis. miR-20a was reported to induce mesenchymal to epithelial transition in MDA-MB-231 cells and its endogenous expression varies directly with invasiveness of breast cancer cells. The inverse and direct correlation of invasiveness with miR-20a and Nucleolin respectively led us to study the post-transcriptional regulation of MMP2 by miR-20a and mRNA stabilizing protein, Nucleolin.

Effects of menstrual characteristics, symptoms and hygiene-related practices on menstrual experience: A comparative study between freeholder and tenant adolescent schoolgirls of North 24 Parganas, West Bengal, India.

Adolescence is a significant event in woman's life when the process of menstruation occurs with several physical, mental and physiological developments. Menstrual experience of women is largely determined by environmental factors occurring during this period. In India, disparities in numerous factors result in different menstrual characteristics, menstruation-related symptoms and menstrual hygiene-related practices.

Strong and Confined Acids Control Five Stereogenic Centers in Catalytic Asymmetric Diels-Alder Reactions of Cyclohexadienones with Cyclopentadiene.

We describe a highly enantioselective Diels-Alder reaction of cross-conjugated cyclohexadienones with cyclopentadiene, in which five stereocenters are effectively controlled by a strongly acidic and confined imidodiphosphorimidate catalyst. Our approach provides tricyclic products in excellent stereoselectivity. We also report methods to convert the obtained products into useful intermediates and a computational study that aids in gaining deeper insight into the reaction mechanism and origin of stereoselectivity.

Involvement of HuR in the serum starvation induced autophagy through regulation of Beclin1 in breast cancer cell-line, MCF-7.

Starvation is a cellular stress that induces autophagy, a conserved cellular self-digestion mechanism that allows cells to degrade and recycle damaged proteins and organelles. The present study illustrated that during serum deprivation, Beclin1, a crucial gene that is essential for autophagosome formation in autophagy, gets controlled post-transcriptionally in breast cancer cell-line MCF-7. RNA affinity chromatography and co-immunoprecipitation confirmed the association of HuR with 3'-UTR of beclin1 mRNA.

Establishment of twist-1 and TGFBR2 as direct targets of microRNA-20a in mesenchymal to epithelial transition of breast cancer cell-line MDA-MB-231.

Messenchymal to epithelial transition (MET) is a significant physiological phenomenon involved in embryogenesis and cancer. This study aims at investigating the mechanism of microRNA-20a (miR-20a) mediated regulation of mesenchymal to epithelial transition and identification of its direct target genes in breast cancer cell-line, MDA-MB-231. Reduced migratory and invasive property, altered cellular morphology along with reduced capability for attachment to basement membrane was acquired by over-expression of miR-20a in invasive MDA-MB-231 cell-line initially expressing low level of this micro-RNA, indicating direct correlation between abundance of miR-20a and metastatic property.

Withaferin A induced impaired autophagy and unfolded protein response in human breast cancer cell-lines MCF-7 and MDA-MB-231.

The autophagy-lysosome pathway and the ubiquitin-proteasome systems are the two major routes for eukaryotic intracellular protein clearance. Cancerous cells often display elevated protein synthesis and byproduct disposal, thus, inhibition of the protein degradation pathways became an emerging approach for cancer therapy. The present study revealed that withaferin-A (WA), the biologically active withanolide derived from Withania somnifera, initially induced formation of autophagosomes in human breast cancer cell-lines, MCF-7 and MDA-MB-231.

Asymmetric Catalysis of the Carbonyl-Amine Condensation: Kinetic Resolution of Primary Amines.

A Brønsted acid catalyzed kinetic resolution of primary amines is described that is based on the condensation between an amine and a carbonyl compound. 1,3-Diketones react with racemic α-branched amines to furnish the corresponding enantioenriched enaminone and recovered starting material. Good to excellent enantioselectivity was observed with both aromatic and aliphatic primary amines.

Withaferin A Induces ROS-Mediated Paraptosis in Human Breast Cancer Cell-Lines MCF-7 and MDA-MB-231.

Advancement in cancer therapy requires a better understanding of the detailed mechanisms that induce death in cancer cells. Besides apoptosis, themode of other types of cell death has been increasingly recognized in response to therapy. Paraptosis is a non-apoptotic alternative form of programmed cell death, morphologically) distinct from apoptosis and autophagy.

Nitrated Confined Imidodiphosphates Enable a Catalytic Asymmetric Oxa-Pictet-Spengler Reaction.

The development of a highly enantioselective catalytic oxa-Pictet-Spengler reaction has proven a great challenge for chemical synthesis. We now report the first example of such a process, which was realized by utilizing a nitrated confined imidodiphosphoric acid catalyst. Our approach provides substituted isochroman derivatives from both aliphatic and aromatic aldehydes with high yields and excellent enantioselectivities.

Biocompatibility of calcined mesoporous silica particles with ventricular myocyte structure and function.

In vivo and in vitro systems were employed to investigate the biocompatibility of two forms of calcined mesoporous silica microparticles, MCM41-cal and SBA15-cal, with ventricular myocytes. These particles have potential clinical use in delivering bioactive compounds to the heart. Ventricular myocytes were isolated from 6 to 8 week male Wistar rats.

Lanthanide oxochalcogenido clusters.

Lanthanide chalcogenolates react with either TeO(2) in pyridine or py-SO(3) in THF to give oxychalcogenido clusters. The sulfido derivatives (THF)(8)Ln(8)S(2)O(2)(SePh)(16) (Ln = Ce, Nd) are isostructural with previously reported oxoselenido compounds, and must be prepared at low temperatures to avoid the introduction of Se into the sulfide position. Analogous telluride derivatives for the early lanthanides were not obtained, but reactions of in situ prepared Ln(TePh)(3) with elemental Te and TeO(2) gave a complicated heterocluster product, with tetrametallic polytelluride [(py)(7)Ln(4)(mu(4)-Te)(mu(2)-Te(2))(2)(mu-eta(2)-eta(2)-Te(2)Te(Ph)Te(2))(TePh)] co-crystallizing with the oxotellurido compound [(py)(5)Ln(3)(mu(3)-O)(mu(2)-Te(2))(3)(TePh)] (Ln = Ho, Er).