Diastereospecific cyclopropanation of glycals 1, 2, 3, 4, and 41 was carried out using either dihalocarbene addition or zinc-carbenoid addition to yield 1,2-cyclopropanated sugars. Dichloro- and dibromocarbenes added stereoselectively anti to the C3 benzyloxy group, whereas (under Simmons−Smith conditions) the cyclopropanes were formed syn to the same substituent. The reactions of these 1,2-cyclopropanated sugars to provide either ring expanded glycosides or C2-branched chain glycosides were explored. Solvolytic ring expansion of 1,2-dibromocyclopropanated sugars with K2CO3 in refluxing methanol yielded the corresponding chiral oxepins 20−22. Electrophilic ring openings of parent cyclopropanes (14 and 17 derived from glucal 1) were carried out with different electrophiles to give functionalized 2-deoxy-2-C-branched chain glycosides. The ring openings of 14 in different solvents resulted in both α- and β-anomers, whereas 17 gave exclusively the α-anomer.

Chlorinated nitroaromatic compounds (CNAs) are persistent environmental pollutants that have been introduced into the environment due to the anthropogenic activities. Bacteria that utilize CNAs as the sole sources of carbon and energy have been isolated from different contaminated and non-contaminated sites. Microbial metabolism of CNAs has been studied, and several metabolic pathways for degradation of CNAs have been proposed. Detoxification and biotransformation of CNAs have also been studied in various fungi, actinomycetes and bacteria. Several physicochemical methods have been used for treatment of wastewater containing CNAs; however, these methods are not suitable for in situ bioremediation. This review describes the current scenario of the degradation of CNAs.

Pyrazines are a group of 1,4 dinitrogen substituted benzenes. They have near ubiquitous biological distribution and majority are anthropogenic. The demand for pyrazines in the recent years has increased owing to their vast applications in the field of food, agriculture and medicine. They are widely distributed in plants, animals and microorganisms. Pyrazines are synthesized and degraded by a few bacteria and fungi. Microbial transformation of many pyrazines aided in the synthesis of several novel molecules. This review discusses the microbial metabolism of pyrazines.

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Arcobacter anaerophilus sp. nov., isolated from an estuarine sediment and emended description of the genus Arcobacter Two strains (JC83, JC84 T ) of obligately anaerobic, H 2 S-producing bacteria were isolated from estuarine sediment samples collected from Gangasagar, West Bengal, India. Cells were Gramstain-negative, non-motile rods. Both strains were positive for oxidase, negative for catalase, hydrolysed casein, reduced nitrate and utilized citrate. Both strains grew chemoorganoheterotrophically with optimal pH of 7-8 (range 7-10) and at 30 6C (range 25-37 6C). C 16 : 1 v7c, C 18 : 1 v7c, C 16 : 0 and C 12 : 0 were the major fatty acids of both strains with minor amounts of C 14 : 0 , C 12 : 0 3-OH and C 18 : 0 . Polar lipids of both strains included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, phosphatidylcholine, phosphatidylinositol, an unidentified aminolipid (AL2), an unidentified phospholipid (PL2) and an unidentified lipid (L3). MK-6 was the major respiratory quinone. The DNA G+C content of strains JC83 and JC84 T was 25.0 and 24.6 mol%, respectively. The strains showed DNA reassociation .85 % (86.0±0.5 %) (based on DNA-DNA hybridization). Based on 16S rRNA gene sequence analysis, both strains were identified as belonging to the family Campylobacteraceae of the class Epsilonproteobacteria with Arcobacter marinus CL-S1 T (95.4 % sequence similarity) as their closest phylogenetic neighbour. On the basis of morphological, physiological and chemotaxonomic characteristics as well as phylogenetic analysis, strains JC83 and JC84 T are considered to represent a novel species, for which the name Arcobacter anaerophilus sp. nov. is proposed. The type strain is JC84 T (5KCTC 15071 T 5MTCC 10956 T 5DSM 24636 T ). An emended description of the genus Arcobacter is provided.