Biomedical subjects
Publications and source records attributed to G Topçu.
The known ent-kaurene diterpenes 1-9 and a new ent-labdane, ent-6beta,8alpha-dihydroxylabda-13(16),14-diene (10), were isolated from the whole plant of Sideritis argyrea. Their structures were elucidated based on one- and two-dimensional NMR techniques and HRMS.
The roots of Lavandula stoechas ssp. stoechas afforded eleven known triterpenes, two steroids and two aromatics, in addition to two new triterpenes, 18-hydroxy-27-norolean-12,14-dien-30-al-28-oic acid and 3 beta-hydroxy-1-oxo-olean-12-ene-30-al-28-oic acid. Their structures were determined by spectroscopic analyses. The chloroform extract and some isolated compounds were evaluated for their growth inhibitory activity against several mammalian cell lines.
The acetone extract of Nepeta caesarea yielded four new nepetalic acid derivatives, 3'alpha-[beta-sitosteryl-3beta-oxy]dihydronepetalactone (1), 3'beta-[5alpha-stigmast-7-ene-3beta-oxy]dihydronepetalact one (2), 3'alpha-[olean-12-ene-28-oyl-3beta-oxy]dihydronepetalactone (3), and 3'alpha-[lup-20(29)-ene-28-ol-3beta-oxy]dihydronepetalactone (4). The structures were elucidated by NMR and MS techniques.
From the hexane extract of berries of Juniperus excelsa, one new and four known diterpenes were isolated besides a known sesquiterpene. The structures of the known diterpenes were identified as isopimaric, isocommunic, (-)ent-trans communic and sandracopimaric acids, along with the sesquiterpene 4a-hydroxycedrol and the new compound which was elucidated as 3 alpha-acetoxylabda-8(17),13(16),14-trien-19-oic acid (juniperexcelsic acid). Cytotoxic activity of the hexane extract was investigated against a panel of cell line and found highly active against LNCaP, KB-V (+VLB) and KB-V (-VLB) cell lines. Furthermore, the hexane and methanol extracts, and the new compound were found to be moderately active against Mycobacterium tuberculosis.