Search PubMed⌕ Search

Biomedical subjects

M Cushman

Publications and source records attributed to M Cushman.

133 records · Page 8Linked to original sources
PubMedDate not supplied

Synthesis of novel phosphoramidite reagents for the attachment of antisense oligonucleotides to various regions of the benzophenanthridine ring system.

Four benzophenanthridine phosphoramidite reagents have been prepared in which the linker chain between the benzophenanthridine and the phosphoramidite moiety is attached to C-2, C-6, C-9, and C-12 of the benzophenanthridine ring system. These benzophenanthridine phosphoramidites should prove to be useful in the syntheses of antisense oligonucleotide-intercalator conjugates in which the linker chain is attached to various regions of the benzophenanthridine intercalator. One of the new benzophenanthridine phosphoramidite reagents was used to prepare an antisense oligonucleotide-intercalator conjugate in which the oligonucleotide TCAGTGGTp was connected at its 5'-hydroxyl group through a linker chain to the C-2 hydroxyl group of a benzophenanthridine.

Amides↗
PubMedDate not supplied

Reinvestigation of the conformations of a variety of hexahydrobenzo[c]phenanthridine alkaloids by 470 MHz PMR and 50 MHz CMR spectroscopy.

The high resolution pmr and cmr spectra of a variety of benzo[c]phenanthridine alkaloids and their CF3COOD salts were examined. The chemical shift of H-14 was found to be a reliable indicator of the orientation of the N-methyl group. The conformations of the C rings were assigned on the basis of the coupling constants between H-11 and the two H-12 protons. On the basis of the pmr spectra of (+)-14-epicorynoline (9) and (+/-)-14-epicorynoline-6,6,12 alpha-d3 (13), a revision of certain previous C ring conformations is indicated.

Alkaloids↗
PubMedDate not supplied

Synthesis and evaluation of hydroxylated flavones and related compounds as potential inhibitors of the protein-tyrosine kinase p56lck.

An array of hydroxylated flavones and related compounds was synthesized and evaluated for inhibition of the in vitro protein-tyrosine kinase activity of p56lck, an enzyme that is thought to play a key role in mediating signal transduction from the CD4 receptor during lymphocyte activation. In general, the most active compounds had hydroxyl groups on both the A and C rings. At least two hydroxyl groups were required for good inhibitory activity, and the relative positions of these groups played an important role in determining potency. Compounds without hydroxyl groups were inactive as inhibitors.

Flavonoids↗
PubMedDate not supplied

Cytotoxicities of some flavonoid analogues.

An array of 55 flavones having a variety of substituents was evaluated for cytotoxicity in five cancer cell cultures: A-549 lung carcinoma, MCF-7 breast carcinoma, HT-29 colon adenocarcinoma, SKMEL-5 melanoma, and MLM melanoma. Fifteen of the 55 flavone derivatives were significantly active against at least one of these cell cultures, and 4'-[(t-butyldi-methylsily)oxy]-7,8-dihydroxy-3',5'- dimethoxyflavone [40] was the most active of all. Structure-activity relationships of these compounds are discussed.

Antineoplastic Agents↗