title: Relationship between pi-electron distribution and anticancer activity of benzo[a]phenothiazines.
abstract: In order to study the correlation between the anti-tumor activity of benzo[a]phenothiazines and the electron densities, the Huckel orbital method and modified-neglect-of-diatomic overlap (MNDO) orbital method were used. 9-Methyl-12H-benzo[a]phenothiazine (2), which showed the most potent anticancer activity among benzo[a]phenothiazines, had the highest charge of nitrogen atom (QN), L-region (QL) and M-region (QM) in the molecule. The other derivatives, which showed weaker anticancer activity, had a much reduced value of these charges (QN, QL, QM). The data suggest that stability of pi-electron in 1 benzene ring and 1 naphthalene ring in the benzo[a]phenothiazine skeleton might be responsible for the induction of anticancer activity.
authors.affiliation: Department of Medicinal Chemistry, Meiji College of Pharmacy, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Motohashi
authors.forename: Y
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Wakabayashi
authors.forename: H
authors.initials: H
authors.lastname: Sakagami
authors.forename: J
authors.initials: J
authors.lastname: Molnar
authors.forename: T
authors.initials: T
authors.lastname: Kurihara
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000627:therapeutic use*; D015394:Molecular Structure; D010640:Phenothiazines / Q000737:chemistry* / Q000627:therapeutic use*; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D010640:Phenothiazines