Purshotam Bhan

Antisense Oligonucleoside Methylphosphonates and Their Derivatives

Abstract The effects of psoralen derivatized oligo-2′-deoxyribonucle-oside methylphosphonates on VSV-infected cells and the interaction of a oligo-2′-O-methylribonucleoside methylphosphonate with a complementary oligoribonucleotide are described.

Syntheses and Interactions of Oligodeoxyribonucleotides Containing 2′-Amino-2′-Deoxyuridine

Abstract Oligodeoxyribonucleotides containing 2′-amino-2′-deoxy-uridine (dU) were synthesized and their ability to form duplexes with complementary DNA or RNA oligonucleotides was studied. Substitution of dU with dU in these oligomers results in lowered Tms of the duplexes.

Biosynthetic and structural studies on pheomelanin

13C-NMR spectroscopy of pheomelanin biopolymers, prepared from isotopically enriched precursors, has been developed as a tool for structure elucidation of melanins. By employing large pulse-widths and short cycle time, only the signals originating from labeled carbons are observed in the high-resolution spectra of these polymers.

A Convenient Preparation of Protected 2′-0-Methylguanosine

Abstract Protected guanosine nucleosides can be converted directly to their 2′-0-methyl derivatives by methylation with trimethylsilyldiazomethane in the presence of stannous chloride. This procedure circumvents the need to use the potentially hazardous reagent, diazomethane.

Inhibition of 5-α-Reductase (TYPE-II) Expression by Antisense 3′-Deoxy-(2′-5′) Oligonucleotide Chimeras

Abstract ABSTRACT: 3′-Deoxy-(2′-5′) oligonucleotides bind selectively to complementary RNA but not to DNA. 3′-Deoxy-(2′-5′) phosphorothioate ODN chimeras embedded with a short stretch of 3′-5′ phosphorothioate cassette are potent inhibitors of steroid 5-α-reductasc expression with significantly less non-specific interactions in cell culture.