PubMed Health⌕ Search

Biomedical subjects

A M Sapse

Publications and source records attributed to A M Sapse.

23 records · Page 2Linked to original sources
PubMed1985

Ab initio studies of the antiviral drug 1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl) thymine.

The antiviral drug 1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl) thymine (FMAU) exhibits a high therapeutic index against a number of herpesviruses. As with other drugs which are nucleoside analogs, such as 1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl)-5-iodocytosine and others, the activity seems to be strongly related to the presence of a fluorine atom in the sugar moiety, in the arabino position. Theoretical calculations, using quantum-chemical methods, are used to elucidate the role of the fluorine in the arabino position and to provide information about the sugar puckering. The results seem to indicate that the fluorine atom prevents the rotation of the base around the sugar-base bond, locking it into an anti structure (Fig. 2,A3) which might be related to its exposure to enzymatic attack. The sugar study confirms the endo position (above the plane) of the C'2 carbon as opposed to the endo position of the C'3 carbon.

Antiviral Agents↗
PubMed1984

Self-consistent-field comparative studies of some nitrosoureas and nitrosamides.

Ab initio (self-consistent-field) calculations are performed in order to obtain information about the most stable conformers of methylnitrosourea, chloroethyl nitrosourea, and their corresponding amides (methylnitrosamide and chloroethylnitrosamide). While nitrosoureas are found to exhibit a Z-conformation, nitrosamides are found to exhibit an E-conformation, a difference which could account for their different stabilities toward in vivo decomposition and which could, as such, influence their carcinostatic activity.

Chemical Phenomena↗
PubMed1981

A self-consistent field molecular orbital study of hydroxyguanidine.

Theoretical self-consistent field molecular orbital calculations indicate that the hydroxyguanidinium ion can dissociate in alkaline or neutral medium by the loss of the hydroxyl proton, leading to the formation of a strong nucleophilic agent which can attack a positive receptor in enzymes, acting in this way as an antitumor and an antiviral agent. Geometry optimization, total energies, and net atomic charges are calculated using a Gaussian basis set for the hydroxyguanidinium ion and its conjugate bases.

Antineoplastic Agents↗
PubMed1971

Parameterization of in vivo leukemic cell populations.

A quantitative mathematical formalism which was previously introduced has been utilized to obtain the cell kinetic parameters which characterize the in vivo leukemic myeloblast cell populations in two patients studied by Clarkson and his coworkers. The principal tentative conclusions are: (a) all cells which are actively proliferating must enter the resting state following cell division; (b) about 90% of the cells are in the resting state; (c) the generation time of the cells in the active state is about 25 hr and is essentially the same as the generation time of normal myeloblast cells.

Cell Division↗