Identification of a hydrolyzable tannin, oenothein B, as an aluminum-detoxifying ligand in a highly aluminum-resistant tree, Eucalyptus camaldulensis.

Eucalyptus camaldulensis is a tree species in the Myrtaceae that exhibits extremely high resistance to aluminum (Al). To explore a novel mechanism of Al resistance in plants, we examined the Al-binding ligands in roots and their role in Al resistance of E. camaldulensis.

Identification of three alcohol dehydrogenase genes involved in the stereospecific catabolism of arylglycerol-beta-aryl ether by Sphingobium sp. strain SYK-6.

Degradation of arylglycerol-beta-aryl ether is the most important process in bacterial lignin catabolism. Sphingobium sp. strain SYK-6 degrades guaiacylglycerol-beta-guaiacyl ether (GGE) to alpha-(2-methoxyphenoxy)-beta-hydroxypropiovanillone (MPHPV), and then the ether linkage of MPHPV is cleaved to generate alpha-glutathionyl-beta-hydroxypropiovanillone (GS-HPV) and guaiacol.

Microbial conversion of glucose to a novel chemical building block, 2-pyrone-4,6-dicarboxylic acid.

2-Pyrone-4,6-dicarboxylic acid (PDC) is a catabolic intermediate in Sphingobium sp. SYK-6 (previously characterized as Sphingomonas paucimobilis SYK-6), which is a degrader of lignin-derived aromatic compounds. Recently, PDC has been also characterized as a novel starting material for several potentially useful synthetic polymers.

Antioxidants from steamed used tea leaves and their reaction behavior.

The most efficient steaming conditions below 200 degrees C for extracting antioxidants from used tea leaves and their reaction behavior during the steaming treatment were investigated. The antioxidative activity of the steamed extracts increased with increasing steaming temperature, and the yield of the ethyl acetate extract fraction from each steamed extract showing the greatest antioxidative activity also increased. Caffeine, (-)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin, (-)-catechin gallate, (-)-epicatechin gallate, (-)-gallocatechin gallate, (-)-epigallocatechin gallate and gallic acid were identified from the ethyl acetate extract fraction.

Efficient production of 2-pyrone 4,6-dicarboxylic acid as a novel polymer-based material from protocatechuate by microbial function.

Sphingomonas paucimobilis SYK-6, which can degrade various low molecular weight compounds derived from plant polyphenols such as lignin, lignan, and tannin, metabolizes these substances via 2-pyrone-4,6-dicarboxylic acid (PDC). We focused on this metabolic intermediate as a potential raw material for novel, bio-based polymers. We cloned the ligAB and ligC genes of SYK-6, which respectively encode protocatechuate 4,5-dioxygenase and 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase, into a broad host range plasmid vector, pKT230MC.

3-O-alkyl-D-glucose derivatives induce fruit bodies of Pleurotus ostreatus.

Amphipathic glucose derivatives 3-O-octyl- and 3-O-decyl-D-glucose were synthesized, and the ability to induce fruit bodies on Pleurotus ostreatus was examined. Surfactants such as CHAPS, CHAPSO, MEGA-8, MEGA-9, and MEGA-10 were also assayed. The result was that both glucose derivatives could stimulate fruiting on P.

Facile Synthesis and NO-Generating Property of 4H-[1,2,5]Oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-Oxides.

4H-[1,2,5]Oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxides (2) are conveniently prepared in high yields by the oxidative intramolecular cyclization of 6-amino-5-nitro-1H-pyrimidine-2,4-diones (1) employing iodosylbenzene diacetate as an oxidant in the presence of lithium hydride. The generation of nitric oxide (NO) and NO-related species from 2 occurs in the presence of thiols such as N-acetylcysteamine, cysteine, and glutathione under physiological conditions. The evidence for the NO generation derives from mechanistic interpretations for the reaction of 2 with thiols and other chemical observations.