The RNA ligase RtcB is conserved in all domains of life and is essential for tRNA maturation in archaea and metazoa. Here we show that bacterial and archaeal RtcB catalyze the GTP-dependent ligation of RNA with 3'-phosphate and 5'-hydroxyl termini. Reactions with analogues of RNA and GTP suggest a mechanism in which RtcB heals the 3'-phosphate terminus by forming a 2',3'-cyclic phosphate before...

Sir: Kanamycins are inactivated by enzymes of resistant bacteria phosphorylating or adenylylating the 3', 4' or 2"-hydroxyl groups' 21 , among which the 3'-hydroxyl group is most frequently modified. Syntheses of 3'-deoxykanamycin A3), 3',4'-dide-oxykanamycin B4) (dibekacine), and other deoxy derivatives of kanamycins and related aminogly-coside antibiotics were the major solution"" in order to...

By the introduction of binary hydroxyl groups into poly(p-phenylenebenzoxazole) (PBO) macromolecular chains, a series of dihydroxypoly(p-phenylenebenzobisoxazole) (DHPBO) chains were prepared, and the effect of the hydroxyl groups on the axial compression property of DHPBO fibers was investigated. The variable-temperature Fourier transform infrared spectrum proved the existence of hydrogen bond...

T he hydroxyl group is one of the most important functional groups of naturally occurring organic molecules. All carbohydrates and their derivatives, including nucleic acids, have hydroxyl groups. Some amino acids, most steroids, many terpenes, and plant pigments have hydroxyl groups. These substances serve many diverse purposes for the support and maintenance of life. One extreme example is th...

Dihydropyrazines (DHPs), which generate hydroxyl and carbon-centered radicals, cleaved DNA single-strand. It is new knowledge that DHPs were recently determined to produce 8-hydroxydeoxyguanosine. The remarkable increase in the DNA strand-cleavage activity upon the addition of Cu2+ suggests that the primary reactive species is carbon-centered radicals rather than the hydroxyl radical generated ...

the beta0diketone derivatives of nitroimidazole were synthesized from the reaction of magnesium salt of beta-ketoaccids 3 with imidazolide 4. the raction of beta-diketones with hydroxylamine hydrochloride afforded either the isoxazoles or the 5-hydroxyl-2-isoxazolines.

1,1’-(ethane-1,2-diyl)dipyridinium bistribromide (edpbt) was used as a chemoselective and effective organocatalyst for the silylation of hydroxyl groups as well as desilylation of trimethylsilyl ethers under mild conditions at room temperature with good to excellent yields.