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Abstract: Granulite grade marble layers interlayered with metapelitic granulites from Lützow Holm Bay, East Antarctica, provide insight into fluid–rock interactions during burial to and exhumation from lower crustal levels. Sub-millimeter scale strontium, oxygen and carbon isotope variations along with LA-ICPMS trace element geochemistry and mineral chemistry of texturally characterized carbonates and associated minerals helped to reconstruct the multistage metamorphic fluid history. Fluid–rock interaction dating back to prograde metamorphism are still preserved in consistently low oxygen and high strontium isotope compositions (δ 18O=12‰; 87Sr/86Sr(550Ma) =0.7248) within a massif dolomitic marble layer that escaped significant later metasomatism. In most marbles, total re-crystallization and isotopic resetting occurred in the presence of “externally derived” hyper-saline fluids that circulated along the carbonate layers during the early stages of prograde metamorphism. This leads to a trend of increased radiogenic Sr in marbles towards the value of associated metapelitic rocks that have 87Sr/86Sr(550Ma) of 0.764. LA-ICPMS studies on trace elements in carbonate and associated silicate minerals at different textural settings, distinguished using cathodoluminescence microscopy, revealed multiple metasomatic events during retrograde metamorphism. Trace element contents of Ba, Sr, Pb and U gave compelling evidence for metasomatic alteration that postdate the exsolution of carbonate at ~600ºC, which can be correlated with the fluids released from the crystallization of anatectic melts and pegmatites. Subsequently, meteoric fluid infiltration occurred at a shallower level of the crust and caused extreme oxygen isotopic heterogeneity (δ 18O=14.7~−4.9‰) and imprinted high concentration of fluid mobile elements. Taken together our results emphasize the importance of integrating textural and chemical heterogeneities to reveal the multiple episodes of fluid–rock interaction processes in a dynamic continental crust, which has major implications on migration of fluids and material and help in formulating models on the geodynamic evolution of crust. [Copyright &y& Elsevier]

The synthesized imidazolyl substituted δ2-isoxazolines were subjected to Phospholipase A2 (PLA2) enzyme inhibitory activity against snake venom source and their structure–activity relationship with respect to different groups attached to this moiety is reported for the first time. The crystal structure of the compound 2-butyl-5-chloro-3H-imidazolyl-4-carbaldehyde oxime 2, an intermediate for the construction of isoxazolines is reported. These compounds exerted a significant PLA2 enzyme inhibitory activity against group II PLA2. The in vivo activity on mice of selected compounds 3bI and 3bIV shows the comparable anti-inflammatory activity with the known standard ursolic acid. [Copyright &y& Elsevier]

TCTA–DMF (2,4,6-trichloro-1,3,5-triazine/ N , N ′-dimethylformamide) adduct has been used as a Vilsmeier–Haack type reagent for effective synthesis of 2-chloro-3-formyl quinolines from acetanilides under conventional and ultrasonically assisted conditions. The reaction times under sonication are quite significantly shorter than conventional methods even though the yields obtained under sonication are comparable with those obtained under reflux conditions. [ABSTRACT FROM AUTHOR]

Abstract: Characterization of fluid inclusions in graphite-bearing charnockites from the southwestern part of the Madurai Granulite Block in southern India reveals a probable relation with the formation and break down of graphite during the high-grade metamorphism. The first-generation monophase pure CO2 inclusions, the composition of which is confirmed by laser Raman spectroscopy, recorded moderate density (0.77–0.87g/cc) corresponding to low tapping pressure (around 2kb) than that of the peak granulite-facies metamorphism. The precipitation of graphite, as inferred from graphite inclusions and δ 13C values of the graphite from the outcrops, is interpreted as the cause of this lowering of fluid density. An intermediate generation of pseudosecondary inclusions resulted from the re-equilibration or modification of the first-generation fluids and the CO2 formed is interpreted to be the oxidation product from graphite. The youngest generation of fluids which caused widespread retrogression of the granulites is a low-temperature (∼350°C) high-saline (32.4–52.0wt% NaCl equivalent) brine. Carbon isotope data on the graphite from the charnockites show δ 13C values ranging from −11.3 to −19.9‰, suggesting a possibility of mixing of carbon sources, relating to earlier biogenic and later CO2 fluid influx. Combining the information gathered from petrologic, fluid inclusion and carbon stable isotope data, we model the fluid evolution in the massive charnockites of the southwestern Madurai Granulite Block. [Copyright &y& Elsevier]