ABSTRACT
OBJECTIVES: Plant-derived natural substances, such as capsaicin, with potent antiproliferative activity against cancer cells in vitro are considered to be promising nutraceuticals in anticancer therapy. Nevertheless, the limited systemic bioavailability of phytochemicals may raise questions regarding the physiological relevance of their phytochemical effects in vivo. Thus, the search for novel phytochemical-based substances with more efficient anticancer action is needed. METHODS: In the present study, a capsaicin analogue, namely, capsaicin epoxide, was synthesized, and its cytotoxic potential against cancer cells was evaluated and compared to that of capsaicin through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and multi-caspase assays. The abilities of capsaicin and capsaicin epoxide to induce oxidative stress were estimated using redox-sensitive fluorogenic probes: 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA) and dihydroethidium. RESULTS: The structure and purity of the synthesized product were confirmed by nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, and gas chromatography. Normal human dermal fibroblasts were not susceptible to treatment with the agent, whereas a cancer cell type-specific response was observed. Human breast carcinoma cells were found to be the most sensitive to capsaicin epoxide treatment compared with capsaicin treatment, and the action of capsaicin epoxide was oxidant based. DISCUSSION: Our data indicate that the antiproliferative activity of capsaicin epoxide is potentiated in vitro, when used at much lower concentrations compared with capsaicin at similar concentrations. Thus, the findings of this study may have implications for phytochemical-based anticancer drug development.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Capsaicin/analogs & derivatives , Oxidants/pharmacology , Animals , Antineoplastic Agents, Phytogenic/chemical synthesis , Antineoplastic Agents, Phytogenic/chemistry , Apoptosis/drug effects , Capsaicin/pharmacology , Cell Line, Tumor/drug effects , Chemistry Techniques, Synthetic , Drug Screening Assays, Antitumor , Fluoresceins , Humans , MCF-7 Cells/drug effects , Magnetic Resonance Spectroscopy , Mice , NIH 3T3 Cells/drug effects , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolismABSTRACT
The present work examines the relationship between the structure and chiroptical properties of cyclic sulfites utilizing the electronic circular dichroism (CD) and time-dependent density functional theory (TD-DFT). For some of the model compounds the study was additionally supported by the X-ray diffraction analysis. A comparison of the experimental and simulated CD spectra gave a reasonable interpretation of the Cotton effects observed in the 200-220 nm spectral range. The study revealed a high sensitivity of the CD spectra with regard to the configuration at the sulfur atom as well as the conformation of the ring bearing the sulfite chromophore. The results demonstrated that such a combined treatment enabled the determination of absolute configuration with a high degree of confidence.
ABSTRACT
1 alpha,25-Dihydroxyvitamin D3 (calcitriol, 1) is a bioregulator important for the treatment of various human metabolic diseases and biomedical research. Herein, we report an efficient diastereoselective approach to the key trans-hydrindane building block for calcitriol synthesis (2a) starting from the readily accessible optically active tetrahydroindenedione derivative (Hajos dione, 3). It was found that epoxide ring opening in a related hydroxy epoxide (7) with sodium cyanoborohydride-BF3 x Et2O occurs by hydride anion addition at the ring juncture position to produce a vicinal diol with the trans-hydrindane ring system (6a). Four methods for selective deoxygenation of the sterically less shielded hydroxy group in diol 6a were examined with an approach based on a cyclic sulfate of the diol as the most efficient and operationally convenient method.
Subject(s)
Indenes/chemistry , Oxygen/chemistry , Vitamin D/chemical synthesis , Crystallography, X-Ray , Hydroxylation , Models, Molecular , Molecular Structure , Vitamin D/chemistryABSTRACT
Efficient and operationally simple synthesis of the key trans-hydrindane alcohol building block for the synthesis of calicitriol (1alpha,25-dihydroxyvitamin D(3)) has been developed. Epoxy alcohol prepared almost quantitatively from the Hajos dione was reduced at the quaternary carbon by the Hutchins procedure (NaBH(3)CN-BF(3).Et(2)O). The diol was selectively deoxygenized either using the Barton-McCombie reaction (with Bu(3)SnH-AIBN) or via the respective iodohydrine (with LiAlH(4)). [reaction: see text]
