title: Synthesis, anti-tubulin and antiproliferative SAR of steroidomimetic dihydroisoquinolinones.
abstract: A SAR translation strategy adopted for the discovery of tetrahydroisoquinolinone (THIQ)-based steroidomimetic microtubule disruptors has been extended to dihydroisoquinolinone (DHIQ)-based compounds. A steroid A,B-ring-mimicking DHIQ core was connected to methoxyaryl D-ring mimics through methylene, carbonyl, and sulfonyl linkers, and the resulting compounds were evaluated against two cancer cell lines. The carbonyl-linked DHIQs in particular exhibit significant in vitro antiproliferative activities (e.g., 6-hydroxy-7-methoxy-2-(3,4,5-trimethoxybenzoyl)-3,4-dihydroisoquinolin-1(2H)-one (16 g): GI50 51 nM in DU-145 cells). The broad anticancer activity of DHIQ 16 g was confirmed in the NCI 60-cell line assay giving a mean activity of 33 nM. Furthermore, 6-hydroxy-2-(3,5-dimethoxybenzoyl)-7-methoxy-3,4-dihydroisoquinolin-1(2H)-one (16 f) and 16 g and their sulfamate derivatives 17 f and 17 g (2-(3,5-dimethoxybenzoyl)-7-methoxy-6-sulfamoyloxy-3,4-dihydroisoquinolin-1(2H)-one and 7-methoxy-2-(3,4,5-trimethoxybenzoyl)-6-sulfamoyloxy-3,4-dihydroisoquinolin-1(2H)-one, respectively) show excellent activity against the polymerization of tubulin, close to that of the clinical combretastatin A-4, and bind competitively at the colchicine binding site of tubulin. Compounds 16 f and 17 f were also shown to demonstrate in vitro anti-angiogenic activity. Additionally, X-ray and computational analyses of 17 f reveal that electrostatic repulsion between the two adjacent carbonyl groups, through conformational biasing, dictates the adoption of a "steroid-like" conformation that may partially explain the excellent in vitro activities.
authors.affiliation: Medicinal Chemistry, Department of Pharmacy & Pharmacology, University of Bath, Bath, BA2 7AY (UK).
authors.forename: Mathew P
authors.initials: MP
authors.lastname: Leese
authors.forename: Fabrice L
authors.initials: FL
authors.lastname: Jourdan
authors.forename: Meriel R
authors.initials: MR
authors.lastname: Major
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dohle
authors.forename: Mark P
authors.initials: MP
authors.lastname: Thomas
authors.forename: Ernest
authors.initials: E
authors.lastname: Hamel
authors.forename: Eric
authors.initials: E
authors.lastname: Ferrandis
authors.forename: Mary F
authors.initials: MF
authors.lastname: Mahon
authors.forename: Simon P
authors.initials: SP
authors.lastname: Newman
authors.forename: Atul
authors.initials: A
authors.lastname: Purohit
authors.forename: Barry V L
authors.initials: BV
authors.lastname: Potter
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D015394:Molecular Structure; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D007546:Isoquinolines
keywords: colchicine; dihydroisoquinolinones; electrostatic repulsion; microtubules; tubulin