title: Preparation of novel ring-A fused azole derivatives of betulin and evaluation of their cytotoxicity.
abstract: An efficient scheme to synthesize novel ring-A fused heterocyclic derivatives of betulin was developed. The starting reaction of this synthesis was one-pot selective bacterial oxidation of betulin to betulone used as the key compound to synthesize the substituted azoles such as C(2)-C(3)-fused 1,2,3-triazoles, oxazoles and 1,2,4-triazine, as well as C(1)-C(2)-fused isoxazoles. The semi-synthetic compounds were screened for their cytotoxic activity against human cancer cell lines A549, HCT 116, HEp-2, MS and RD TE32 with use of the photometric MTT assays. Among the tested compounds, N-acetyltriazole of betulin (10) displayed impressive cytotoxic activity with IC502.3-7.5 μM against HCT 116, HEp-2, MS and RD TE32 cell lines as well as 3-methyl-4-oxido-1,2,4-triazine-derivative of betulonic acid (12) that was active against HCT 116 and HEp-2 cell lines with IC501.4 and 1.5 μM, respectively. Comparative experiments showed triazole (10) to have a lower cytotoxicity to normal epithelial cells, in comparison with compound (12). In accord with the in vivo acute toxicity test, the LD50of triazole (10) exceeded 600 mg/kg. The ability of the most potent active triazole (10) to trigger apoptotic cell death was explored in the Annexin V-FITC test and by analyzing of caspase activity and morphological alterations in mitochondria and nuclei of HCT 116 cells.
authors.affiliation: Institute of Technical Chemistry of Ural Branch of the Russian Academy of Sciences, Acad. Korolev St. 3, 614013 Perm, Russia. Electronic address: grishvic@gmail.com.
authors.forename: Victoria V
authors.initials: VV
authors.lastname: Grishko
authors.affiliation: Institute of Technical Chemistry of Ural Branch of the Russian Academy of Sciences, Acad. Korolev St. 3, 614013 Perm, Russia.
authors.forename: Irina A
authors.initials: IA
authors.lastname: Tolmacheva
authors.affiliation: Institute of Technical Chemistry of Ural Branch of the Russian Academy of Sciences, Acad. Korolev St. 3, 614013 Perm, Russia.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Nebogatikov
authors.affiliation: Institute of Technical Chemistry of Ural Branch of the Russian Academy of Sciences, Acad. Korolev St. 3, 614013 Perm, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Galaiko
authors.affiliation: Institute of Technical Chemistry of Ural Branch of the Russian Academy of Sciences, Acad. Korolev St. 3, 614013 Perm, Russia.
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Nazarov
authors.affiliation: Perm State National Research University, Bukirev St. 15, 614990 Perm, Russia.
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Dmitriev
authors.affiliation: Perm State National Research University, Bukirev St. 15, 614990 Perm, Russia; Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev St. 13, 614081 Perm, Russia.
authors.forename: Irena B
authors.initials: IB
authors.lastname: Ivshina
mesh_terms: D001393:Azoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007928:Lethal Dose 50; D015394:Molecular Structure; D014227:Triazines / Q000737:chemistry / Q000633:toxicity; D014315:Triterpenes / Q000737:chemistry* / Q000633:toxicity; D000094062:Betulinic Acid
chemical_list: D001393:Azoles; D014227:Triazines; D014315:Triterpenes; C002503:betulin; D000094062:Betulinic Acid
keywords: Apoptosis; Azoles; Betulin; Heterocycles; MTT assay; Tumor cells