Triple Role of Proton Sponge (DMAN) in the Palladium-Catalyzed Direct Stereoselective Synthesis of C-Aryl Glycosides from Glycals.

The triple role of 1,8-bis(dimethylamino)naphthalene (proton sponge) as a reductant, ligand precursor, and organic base in the palladium-catalyzed Heck-type coupling reaction of glycals with aryl iodides affords the rapid and stereoselective synthesis of 2',3'-unsaturated α-C-aryl glycosides in excellent yields. The role of the proton sponge in reducing palladium(II) to (0) has been studied using cyclic voltammetry, UV-vis, HRMS, and other spectroscopic techniques. This is the first example of a palladium proton sponge complex utilized in coupling reactions. The method is observed to be tolerant of various functional groups, as demonstrated by the huge substrate scope. Moreover, the 2',3'-unsaturated α-C-aryl glycosides were also converted to 3-keto-ß-C-glycosides under sterically hindered pyridinium salt catalysis via a ring-opening and -closing mechanism.

Settling moths are the vital component of pollination in Himalayan ecosystem of North-East India, pollen transfer network approach revealed.

Majority of the pollination related studies are based on the diurnal pollinators, and the nocturnal pollinators received less scientific attention. We reveal the significance of settling moths in pollination of angiosperm families in Himalayan ecosystem of North-East India. The refined and novel method of pollen extraction from the proboscides provides a more robust assessment of the pollen carrying capacity. The study is based on one of the largest data sets (140 pollen transporter moth species (PTMS)), with interpretation based on seasonal as well as altitudinal data. In the present study about 65% moths (91 species) carried sufficient quantities of pollen grains to be considered as potential pollinators (PPMS). Teliphasa sp. (Crambidae) and Cuculia sp. (Noctuidae) are found to carry the highest quantity of pollen. We found pollen grains of 21 plant families and the abundant pollen are from Betulaceae, Fabaceae, Rosaceae and Ericaceae. Species composition of PTMS and PPMS in pre-monsoon, monsoon, and post-monsoon revealed the dominance of Geometridae. Maximum diversity of PTMS and PPMS is found from 2000 to 2500 m altitude. The nocturnal pollen transfer network matrices exhibited high degree of selectivity (H2' = 0.86).

Saliva for diagnosis of SARS-CoV-2: First report from India.

There are very few studies in search of an alternate and convenient diagnostic tool which can substitute nasopharyngeal swab (NPS) specimen for detection of SARS-CoV-2. In the study we analyzed, the comparison and agreement between the feasibility of using the saliva in comparison to NPS for diagnosis of SARS-CoV-2. A total number of 74 patients were enrolled for this study. We analyzed and compared the NPS and saliva specimen collected within 48 h after the symptom onset. We carried out real-time quantitative polymerase chain reaction, gene sequencing for the detection and determination SARS-CoV-2 specific genes. Phylogenetic tree was constructed to establish the isolation of viral RNA from saliva. We used the Bland-Altman model to identify the agreement between two specimens. This study showed a lower cycle threshold (CT ) mean value for the detection of SARS-CoV-2 ORF1 gene (mean, 27.07; 95% confidence interval [CI], 25.62 to 28.52) in saliva methods than that of NPS (mean 28.24; 95% CI, 26.62 to 29.85) specimen although the difference is statistically nonsignificant (p > .05). Bland-Altman analysis produced relatively smaller bias and high agreement between these two clinical specimens. Phylogenetic analysis with the RdRp and S gene confirmed the presence of SARS-CoV-2 in the saliva samples. Saliva represented a promising tool in COVID-19 diagnosis and the collection method would reduce the exposure risk of frontline health workers which is one of the major concerns in primary healthcare settings.

Role of mitochondrial oxidative stress on lymphocyte homeostasis in patients diagnosed with extra-pulmonary tuberculosis.

Extra-pulmonary tuberculosis is often an underrated illness. Recent clinical studies have pointed out that lymphocyte homeostasis is dramatically disturbed as revealed through a series of signs and symptoms. Lymphocytes, the known effector cells of our immune system, play an important role in providing immunologic resistance against Mycobacterium infection. It is important to have quantitative insights into the lifespan of these cells; therefore, we aimed to study the precise effect of gastrointestinal tuberculosis infection on peripheral blood lymphocyte subpopulations and function. Our results indicated that gastrointestinal tuberculosis could increase mitochondrial oxidative stress, lower mitochondrial DNA copy number, promote nuclear DNA damage and repair response, decrease mitochondrial respiratory chain enzyme activities, and upregulate Bcl-2 and caspase-3 gene expression in lymphocytes. We further revealed that Mycobacterium infection induces autophagy for selective sequestration and subsequent degradation of the dysfunctional mitochondrion before activating cellular apoptosis in the peripheral lymphocyte pool. Together, these observations uncover a new role of mitochondrial-nuclear crosstalk that apparently contributes to lymphocyte homeostasis in gastrointestinal tuberculosis infection.