Antiproliferative piperidine alkaloids from giant taro (Alocasia macrorrhiza) / 中国天然药物

The rhizome of giant taro (Alocasia macrorrhiza (L.) Schott), which is a highly adaptable wild plant, is a traditional Chinese herbal medicine. In the current study, the antiproliferative constituents of giant taro were investigated and six new (1-6) and four known piperidine alkaloids (7-10) were isolated from its rhizomes. Their chemical structures and absolute configurations were elucidated using various spectroscopic methods and the Mosher ester method. The isolated alkaloids were screened for the antiproliferative activity through MTT assay. The results indicated that piperidine alkaloids exerted potential antiproliferative activity against HepG2, AGS and MCF-7 tumor cells. Further researches showed that compounds 3-5 dose-dependently decreased the colony formation rate and induced the apoptosis of AGS cells, while compound 4 induced AGS cell death via the proapoptotic pathway. This study demonstrates that the piperidine alkaloids isolated from giant taro exhibit significant antitumor activity, which provides phytochemical evidence for further development and utilization.

Study on chemical constituents of Alocasia macrorrhiza (L.) Schott / 中国药学杂志

OBJECTIVE: To study the chemical constituents of Alocasia macrorrhiza (L.) Schott. METHODS: Chemical constituents were extracted by organic solvents, isolated and purified by chromatographic techniques with silica gel, polyamide, ODS, Sephadex LH-20, semi-preparative HPLC and recrystallization. Their structures were identified on the basis of physicochemical properties and spectral data analyses of MS and NMR, et al. RESULTS: Nine compounds were isolated from its rhizoma and identified as glycosmisic acid (1), N-trans-feruloyltyramine(2), grossamide(3), protocatechuic acid(4), borneol acetate(5), vanillic acid(6), methyl 4-hydroxybenzoate(7), β-daucosterol(8), and β-sitosterol(9). CONCLUSION: Compounds 1-9 were isolated from Alocasia macrorrhiza for the first time.