Synthesis of 7'-(3-hydroxypropyl)fortimicin A and 6'-epifortimicin A

1,10-Di-0-acetyl-2,3,4,6,7,8,9-heptadeoxy-2,6-bis(2, 4-dinitrophenylamino)-L-lyxo-decopyranose (7) and -D-ribo-decopyranose (8) have been prepared from methyl 2-acetamido-2,3,4,6-tetradeoxy-6-nitro-alpha-D-erythro-hexopyranoside via a nitro aldol reaction with 4-[(tetrahydropyranyl)oxy]butanal in the presence of cesium fluoride, and their configurations at C-6 have been established by conversion of the precursor of 8, namely, methyl 2,6-diacetamido-10-O-acetyl-2,3,4,6,7,8,9-heptadeoxy-alpha-D - ribo-decopyranoside, into the known methyl 2,6-diacetamido-2,3,4,6,7,8,9,10-octadeoxy-alpha-D-ribo-d ecopyranoside. The title fortimicin A derivatives, 7'-(3-hydroxypropyl)fortimicin A and 6'-epifortimicin A, have been synthesized by condensation of compound 7 and 8, respectively, with 2,5-di-O-benzoyl-1,4-bis[N-(methoxycarbonyl)]fortamine B, followed by deprotection and introduction of a glycyl group. Their antimicrobial activities have been found to be weak compared to that of fortimicin A.     

Random PCR-based genome sequencing: a non-divide-and-conquer strategy.

We propose a genome sequencing strategy, which is neither divide-and-conquer (clone by clone) nor the shotgun approach. Random PCR-based and PCR relay sequencing constitute the basis of this novel strategy. Most of the genome is sequenced by the former process that requires only a set of non-specific primers and a template DNA. Random PCR-based sequencing reduces redundancy in sequencing by exploiting known sequence information. The number of primers required for random PCR was significantly diminished by using a combination of primers. The former process can be partially replaced by the shotgun method, if necessary. The gap-filling process can be effectively performed by way of PCR relay. The feasibility of this strategy was demonstrated using the Escherichia coli genome. This strategy enhances the global effort towards genome sequencing by being available through the Internet and by allowing the use of preexisting sequence data.     

Complete deficiency of AMP deaminase in human erythrocytes

Four individuals with complete absence of erythrocyte AMP deaminase have been discovered. The subjects appear to be perfectly healthy and there was no evidence of hemolysis. The deficiency was found only in erythrocytes and as expected, mononuclear cells and platelets showed normal level of activity. The activities of all the other purine metabolizing enzymes that were tested were normal. The deficiency is inherited as an autosomal recessive trait.