title: Synthesis and biological evaluation of a novel betulinic acid derivative as an inducer of apoptosis in human colon carcinoma cells (HT-29).
abstract: A novel family of betulinic acid analogues, carrying a triazole unit at C-3 attached through a linker, was synthesized by the application of azide-alkyne "Click reaction". These were screened for their anticancer activity against different cancer cells and normal human PBMC by MTT assay. Compound 2c [(3S)-3-{2-(4-(hydroxymethyl-1H-1,2,3-triazol-1-yl)acetyloxy}-lup-20(29)-en-28-oic acid] was found as the most potent inhibitor of cell line HT-29 with IC50 value 14.9 μM. Its role as an inducer of apoptosis was investigated in this cell line by Annexin-V/PI binding assay and by following its capability for ROS generation, depolarization of mitochondrial transmembrane potential, activation of caspases, PARP cleavage, nuclear degradation and expression of pro- and anti-apoptotic proteins. It exhibited much higher cytotoxicity than the standard drug 5-fluorouracil but showed negligible cytotoxicity towards normal PBMC. Elevated level of ROS generation, activation of caspase 3 and caspase 9, DNA fragmentation, higher expression of Bax and Bad, lower expression of Bcl2 and Bcl-xl, and increased level of Bax/Bcl-xl ratio identified 2c as a promising inducer of apoptosis that follows a mitochondria dependent pathway. Bio-physical studies indicate that compound 2c acts as a minor groove binder to the DNA.
authors.affiliation: Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India.
authors.forename: Biswajit
authors.initials: B
authors.lastname: Chakraborty
authors.affiliation: Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India.
authors.forename: Debasmita
authors.initials: D
authors.lastname: Dutta
authors.affiliation: Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India.
authors.forename: Sanjukta
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India.
authors.forename: Supriya
authors.initials: S
authors.lastname: Das
authors.affiliation: Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India.
authors.forename: Nakul C
authors.initials: NC
authors.lastname: Maiti
authors.affiliation: Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India. Electronic address: padmadas@iicb.res.in.
authors.forename: Padma
authors.initials: P
authors.lastname: Das
authors.affiliation: Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India. Electronic address: chinmay@iicb.res.in.
authors.forename: Chinmay
authors.initials: C
authors.lastname: Chowdhury
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D019073:HT29 Cells; D006801:Humans; D015394:Molecular Structure; D053978:Pentacyclic Triterpenes; D017382:Reactive Oxygen Species / Q000378:metabolism; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry* / Q000494:pharmacology*; D000094062:Betulinic Acid
chemical_list: D000970:Antineoplastic Agents; D053978:Pentacyclic Triterpenes; D017382:Reactive Oxygen Species; D014315:Triterpenes; D000094062:Betulinic Acid
keywords: Betulinic acid; Caspase activation; Cytotoxic activities; DNA binding; Mitochondrial dysfunction; Triazole derivative