Biomedical subjects
Publications and source records attributed to F Latif.
A versatile synthesis of diazopeptides is reported and several new compounds described. It is shown that diazopeptides form readily from gaseous nitrogen dioxide in both neutral buffers and human blood. In these media, diazopeptides are sufficiently stable (half-time 0.5-30 h) to qualify as potential circulating carcinogens.
Genetic markers with high degrees of polymorphisms are of vital importance in the construction of high resolution (2-4 cM) linkage maps of human chromosomes as specified in the short-term goals of the Human Genome Initiative. In this paper, we report on molecular and genetic characterization and physical localization of 11 new multiallele restriction fragment length polymorphism markers on human chromosome 3p. Ten of these represent three- and four-allele polymorphisms of the base substitution type probably at two adjacent restriction sites. One has been identified as a novel mini-satellite sequence comprising a variable copy number tandem repeat array of a G/T-rich 79-bp sequence. This collection of multiallele polymorphic (PIC values: 0.40-0.60) markers should prove valuable and increase the resolution power of the available chromosome 3p genetic markers.
The stereochemistry at the alpha-carbon atom of the styrene moiety in styrene oxide-guanosine products was established, and the stereochemical consequences of reaction of optically active styrene oxide with guanosine were investigated. Inversion of stereochemistry in products at the alpha-carbon of styrene oxide decreased in the sequence 7- much greater than N2- greater than O6-substituted guanosines. These findings show that an extensively ionized substrate is needed for reaction at the exocyclic N2 and O6 sites on guanosine but that the reactive intermediate is not an ideal planar trigonal carbonium ion. This follows because inversion exceeds retention in both of the exocyclic substituted products.