No abstract

Quinoxaline, found in antitumor quinoxaline antibiotics, was found to cleave double stranded DNA at the 5' side guanine of 5'-GG-3' site on irradiation with long wavelength UV light without any additive; furthermore, a bis(quinoxaline-carbohydrate) hybrid system was very effective for DNA cleavage.

No abstract

A novel poly(vinyl alcohol) (PVA) degradation pathway was demonstrated such that the hydroxy group of PVA was first dehydrogenated into the corresponding carbonyl group to form the β-hydroxy ketone moiety which was followed by the aldolase-type cleavage to produce the methyl ketone and the aldehyde terminals by the PVA-assimilating strain, Alcaligenes faecalis KK314. Both the biodegradation steps of dehydrogenation and subsequent aldolase-type cleavage were catalyzed by the same protein having 67 kDa as the holoenzyme and apoenzyme of PVA dehydrogenase, respectively.

The six-membered lactide was polymerized using the ring-opening polymerization with lipase as a catalyst at a temperature between 80 and 130°C in bulk to yield the corresponding polylactide with weight-average molecular weights of up to 126000. The most preferable conditions with respect to the molecular weight of the polylactide are the bulk polymerization using lipase PS at a temperature of 100°C. The D,L-lactide gave higher molecular weight compared to the D,D-and L,L-lactide.