The facile syntheses of a variety functionalized propiolic acids were achieved by carboxylation of alkynylsilanes with carbon dioxide mediated by cesium fluoride under ambient conditions.

Carbon isotope fractionation in metabolic processes following carboxylation of ribulose-1,5-bisphosphate (RuBP) is not as well described as the discrimination during photosynthetic CO(2) fixation. However, post-carboxylation fractionation can influence the diel variation of delta(13)C of leaf-exported organic matter and can cause inter-organ differences in delta(13)C. To obtain a more mechanist...

A microbial enrichment culture from marine sediment was able to grow on hexadecan-2-one as the sole source of carbon and energy under sulfate-reducing conditions. Oxidation of the ketone involved carboxylation reactions and was coupled to sulfide production. This enrichment culture also grew on 6,10,14-trimethylpentadecan-2-one.

BACKGROUND AND AIMS Photosynthetic plasticity in response to a range of environmental factors that include [CO(2)], water availability, light intensity and temperature, is ubiquitous among plants with crassulacean acid metabolism (CAM). The present study examined how seasonal changes in light availability, as experienced by greenhouse CAM crops in northern latitude regions, influence diel carbo...

The magnitude of changes in carboxylation capacity in dominant plant species under long-term elevated CO2 exposure (elevated pCa) directly impacts ecosystem CO2 assimilation from the atmosphere. We analyzed field CO2 response curves of 16 C3 species of different plant growth forms in favorable growth conditions in four free-air CO2 enrichment (FACE) experiments in a pine and deciduous forest, a...

(1) Activation of rat liver mitochondrial functions following glucagon treatment was demonstrated in mitochondria that had not been isolated by the conventional technique of differential centrifugation and washing in sucrose solutions. Crude liver homogenates in 0.3 M-sucrose or 0.15 M-KCI prepared from rats treated with glucagon showed stimulation of State-3 and uncoupled respiration, carboxyl...

Reaction 1, the carboxylation of acety-CoA to form malonylCo& is catalyzed by acetyl-CoA carboxylase, a biotin enzyme (l-6). Reaction 2, the reaction of acetyl-CoA with 7 moles of malonyl-CoA and 14 moles of TPNH to form palmitate, is an incompletely understood complex reaction catalyzed by palmitate synthetase (7-10). In recent years, there has been a number of observations (11-13) demonstrati...

Abstract Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key CO 2 -fixing enzyme in photosynthesis, is notorious for its low carboxylation. We report a highly active and assembly-competent Form II Rubisco from endosymbiont of deep-sea tubeworm Riftia pachyptila (RPE Rubisco), which shows 50.5% higher carboxylation efficiency than that high functioning Synechococcus sp. PCC7002 (7...