Antimony trichloride: A mild and efficient reagent for chemoselective ring

302-307Antimony trichloride mediates regioselective, stereoselective and chemoselective ring opening of oxiranes under mild laboratory conditions with semiquantative yields. A new route to -acetoxychalcones is also explored

An efficient one pot conversion of alkynes to bis(indolyl) and bis(pyrrolyl)alkanes in aqueous ethanol

122-128Mercury (II) chloride efficiently catalyzes the reaction between indoles /pyrrole and substituted phenyl acetylenes to furnish bis(indolyl)alkane and bis(pyrrolyl)alkane in good to excellent yields under room temperature and moderate reaction time. The reaction is carried out in ethanolic water medium

Warming inhibits increases in vegetation net primary productivity despite greening in India

Abstract India is the second-highest contributor to the post-2000 global greening. However, with satellite data, here we show that this 18.51% increase in Leaf Area Index (LAI) during 2001–2019 fails to translate into increased carbon uptake due to warming constraints. Our analysis further shows 6.19% decrease in Net Primary Productivity (NPP) during 2001–2019 over the temporally consistent forests in India despite 6.75% increase in LAI. We identify hotspots of statistically significant decreasing trends in NPP over the key forested regions of Northeast India, Peninsular India, and the Western Ghats. Together, these areas contribute to more than 31% of the NPP of India (1274.8 TgC.year−1). These three regions are also the warming hotspots in India. Granger Causality analysis confirms that temperature causes the changes in net-photosynthesis of vegetation. Decreasing photosynthesis and stable respiration, above a threshold temperature, over these regions, as seen in observations, are the key reasons behind the declining NPP. Our analysis shows that warming has already started affecting carbon uptake in Indian forests and calls for improved climate resilient forest management practices in a warming world

Impact of structural modification on the photophysical response of benzoquinoline fluorophores

Structural influence on the photophysical behavior of two pairs of molecular systems from the biologically potent benzoquinoline family, namely, dimethyl-3-(4-chlorophenyl)-3,4-dihydrobenzo[f]-quinoline-1,2-dicarboxylate, dimethyl-3-(2,6-dichlorophenyl)-3,4-dihydrobenzo[f]quinoline-1,2-dicarboxylate and their corresponding dehydrogenated analogues has been investigated exploiting experimental as well as computational techniques. The study unveils that dehydrogenation in the heterocyclic rings of the studied quinoline derivatives modifies their photophysics radically. Experimental observations imply that the photophysical behavior of the dihydro analogues is governed by the intramolecular charge transfer (ICT) process. However, the ICT process is restricted significantly by the dehydrogenation of the heterocyclic rings. Computational exertion leads to the proposition that the change in the electronic distribution in these molecular systems on dehydrogenation is the rationale behind the dramatic modification of their photophysics

One-pot efficient pseudo-five-components synthesis of 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1<i>H</i>-pyrazol-5-ols) at room temperature assisted by K₂CO₃

<p>A convenient approach for the synthesis of 4,4′-(arylmethylene)-bis(3-methyl-1-phenyl-1<i>H</i>-pyrazol-5-ols) by an efficient one-pot reaction of aromatic aldehydes, phenylhydrazine, and ethyl acetoacetate by using substoichiometric amount of K₂CO₃ in acetonitrile solvent at room temperature is described. This protocol of one-pot synthesis produced a library of bis-pyrazolylmethane derivatives, a potential bioactive compound in very good to excellent yields.</p

The Gastroprotective Role of Acanthus ilicifolius – A Study to Unravel the Underlying Mechanism of Anti-Ulcer Activity

Acanthus ilicifolius (Acanthaceae), a mangrove medicinal plant, is widely used by the local inhabitants of the Sundarbans (India) to treat a variety of diseases. As a part of our continued search for novel bioactive products from mangrove medicinal plants, we were able to document the anti-inflammatory effects of this plant. In the present study, we have performed a detailed evaluation of the gastroprotective activity of the methanolic extract of Acanthus ilicifolius using different models of gastric ulceration. Unlike the conventional non-steroidal anti-inflammatory drugs, a methanolic extract of Acanthus ilicifolius leaves (MEAL) possessing significant anti-inflammatory properties, as revealed from our previous studies displayed in rats in dosages of 200 mg and 400 mg / kg BW after intraperitoneal administration, showed significant protective activity (anti-ulcer activity) against the gastric lesions induced by aspirin, indomethacin, stress, ethanol, and pylorus ligation. In pylorus-ligated rats, administration of Methanolic extract of Acanthus ilicifolius leaves (MEAL) significantly decreased gastric volume, acidity, and peptic activity. Moreover, pre-treatment with MEAL significantly restored the levels of reduced glutathione (GSH) and the antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), along with significant inhibition of both lipid peroxidation and myeloperoxidase (MPO) activity in pylorus-ligated animals. Ulceration induced with ethanol was significantly inhibited with MEAL, and the extract also resulted in the reduction of both lipid peroxidation and myelo-peroxidase activity. Furthermore, in this experimental model, administration of MEAL improved the activities of SOD, CAT, GSH, and GPX. A similar pattern of action was also noticed in cold-restraint stress-induced (CRS) ulceration, where MEAL pre-treatment inhibited CRS-induced ulceration, improved the status of antioxidant enzymes, and also reduced the level of lipid peroxides. These results suggest that extracts of the leaves of Acanthus ilicifolius may exhibit anti-ulcer activities additional to the anti-inflammatory properties