Albitisation at serpentinite-granite contact at Tagadur,Karnataka, India

The occurrence of albitite has been noticed in contact between serpentinite and granite in the Nuggehalli schist belt. The platy parallelism and the linear structure characterising this rock were observed in the orienteda, b andc sections. The fabric of the rock is, the elongation of grains parallel tob, flattening of the grains in theab plane, and the development ofokl shear planes obtained from the quartz axes diagram. It is interpreted that the formation of albitite is due to soda metasomatism of an hornblendic rock by emanations from ultrabasic serpentinite. TheB-tectonite fabric of the rock is a result of pretectonic crystallisation (postcrystalline deformation).     

Synthesis and reactions of binuclear diolefin rhodium(I) compounds bridged by nitrogen heterocycles. Crystal structure of dichloro-di-1,5-cyclooctadiene(μ-pyrazine)-dirhodium(I) [{Rh(1,5-C8H12)Cl}2(μ-C4H4N2)]

Binuclear complexes of rhodium(I) of the type [(dien)(X)Rh(μ-N-N)Rh(X)(dien)] (dien = 1,5-cyclooctadiene or norbornadiene; N-N = pyrazine, 4,4′-bipyridine or Phenazine and X = Cl or Br) with bridging heterocycles have been isolated and their reactions with carbon monoxide, 2,2′-bipyridine and 1,10-phenanthroline investigated. The crystal structure of [(COD)(Cl)Rh(μ-pyrazine)Rh(Cl)(COD)] has been determined.     

Inclusive γ-production in\bar pp interactions at 0.76 and 2.0 GeV/c

The inclusive production of photons in \(\bar pp\) interactions has been studied at incident momenta of 0.76 and 2.0 GeV/c. The inclusive cross sections for γ-production and the average multiplicities of γ, «n _γ», are presented as a function of the charged prong topology. Results on the two particle correlation parametersf ⁰⁰ andf ^?0 are presented. The inclusive distributions of the Feynman variablex and of the transverse momentump _T of the photons are compared with the expectations from charged pion distributions on the basis of charge independence. A search has been made for direct γ-production in \(\bar pp\) interactions at 0.76 GeV/c by looking for events which fit uniquely the hypothesis \(\bar pp \to m\pi ^ + + m\pi ^ - + \gamma \) . An estimate of the ratio $$R = \frac{{\sigma (\bar pp \to m\pi ^ + + m\pi ^ - + \gamma )}}{{\sigma (\bar pp \to m\pi ^ + + m\pi ^ - + \pi ^0 )}}$$ is given.     

General characteristics of\bar pp interactions at low energies in terms of principal axis and impact parameter variables

The reaction configuration in momentum and position space has been investigated in detail from exclusive final states in \(\bar pp\) interactions at centre of mass energies 2.01 and 2.96 GeV. In momentum space one finds a tendency towards a planar configuration at low multiplicities. In position space, one sees the average impact parameter decreasing with increasing multiplicity. At large multiplicities, events become more phase-space like i.e., more central whereas at lower multiplicities the effect ofp _t damping can be seen.     

Facile synthesis of novel (1-Aryl/alkyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol- 4-yl)methyl-2-bromo-4-methylthiazole-5-carboxylates by Cu(I) catalyzed click reaction

A number of novel thiazole-triazole heterocycles bearing (1-aryl/alkyl-1H-1,2,3-triazol-4-yl)methyl- 2-bromo-4-methylthiazole-5-carboxylates was synthesized through the click reaction. The structure of all new synthesized compounds was established by ¹H and ¹³C NMR spectroscopy and mass spectrometry methods.     

The Biosynthetic Gene Cluster of Mushroom-Derived Antrocin Encodes Two Dual-Functional Haloacid Dehalogenase-like Terpene Cyclases

(−)-Antrocin ( 1 ), produced by the medicinal mushroom Antrodia cinnamomea, is a potent antiproliferative compound. The biosynthetic gene cluster of 1 was identified, and the pathway was characterized by heterologous expression. We characterized a haloacid dehalogenase-like terpene cyclase AncC that biosynthesizes the drimane-type sesquiterpene (+)-albicanol ( 2 ) from farnesyl pyrophosphate (FPP). Biochemical characterization of AncC, including kinetic studies and mutagenesis, demonstrated the functions of two domains: a terpene cyclase (TC) and a pyrophosphatase (PPase). The TC domain first cyclizes FPP to albicanyl pyrophosphate, and the PPase domain then removes the pyrophosphate to form 2 . Intriguingly, AncA (94 % sequence identity to AncC), in the same gene cluster, converts FPP into (R)-trans-γ-monocyclofarnesol instead of 2 . Notably, Y283/F375 in the TC domain of AncA serve as a gatekeeper in controlling the formation of a cyclofarnesoid rather than a drimane-type scaffold.     

β-Strand mimetics: formation of bend-strands in oligomers of enantiomeric β-amino acids

Oligomers comprising of enantiomeric cis-oxo-β-norbornene amino acid [2R,3S] and [2S,3R] residues at alternate positions were synthesized and characterized by extensive NMR and MD studies, which showed robust bend-strand secondary structures.     

1‐Arylsulfonyl‐2‐styrylsulfonylthenes — source for a new class of bis heterocycles

New and novel sulfone linked bis heterocycles_ bis pyrroles and pyrrolyl pyrazolines are prepared from 1‐arylsulfonyl‐2‐styrylsulfonylethenes by 1,3‐dipolar cycloaddition methodology.