Sesquiterpenoids and sesquiterpenoid dimers from the stem bark of Dysoxylum parasiticum (osbeck) kosterm.

Two undescribed sesquiterpenoids, namely dysoticans A and B, and three undescribed sesquiterpenoid dimers, namely dysoticans C-E, together with six analogs, were isolated from the stem bark of Dysoxylum parasiticum (Osbeck) Kosterm. (Meliaceae), growing in West Java, Indonesia. Their structures were elucidated based on extensive spectroscopic analysis and theoretical simulations of ECD spectra and 13C NMR shifts. Dysoticans A and B possessed undescribed cadinanes with minor modifications, while C and D featured unprecedented pseudo-sesquiterpenoid dimers through O-ether linkages of cadinanes and guaianes, respectively. Dysotican E was also characterized as the true-sesquiterpenoid dimer featuring eudesmane-germacrene hybrid framework from the Meliaceae family. Furthermore, A-C and E showed moderate activities against the human breast cancer MCF-7 and cervical cancer HeLa cell lines with IC50 values ranging from 22.15 to 45.14 µM. D selectively exhibited significant cytotoxicity against the HeLa cell line with an IC50 value of 13.00 ± 0.13 µM.

A new alkaloid and a new benzaldehyde derivative from the twig of Zanthoxylum rhetsa (Roxb.) DC.

A new alkaloid, 2-acetyl-4-methoxyfuro[2,3-b]quinoline (1), and a new benzaldehyde derivative, (2'S)-4-(2'-hydroxy-3'-methyl-3'-butenoxy)benzaldehyde (2), were isolated from the twig of Zanthoxylum rhetsa (Roxb.) DC. along with twenty-six known compounds (3-28). Their structures were determined by spectroscopic analysis (1D and 2D NMR spectroscopy and HRMS analysis) and comparison with data reported in the literature. Thirteen of the known compounds were evaluated for their cytotoxic activities against human cancer cell lines that included MDA-MB-231, SW1353, A549, and HCT116. (±)-8-Acetonyldihydronitidine (15) showed moderate cytotoxicity toward the SW1353 cancer cell line with an IC50 value of 18.90±0.39 µg/mL, and exhibited weak cytotoxic activity against MDA-MB-231, A549 and HCT116 cell lines with IC50 values of 49.86-71.32 µg/mL.

Cytotoxic xanthones from the roots of Mesua ferrea L.

Five undescribed xanthones, 4-methoxypyranojacareubin, 4-hydroxy-3-prenylpyranoxanthone, 1-hydroxy-5,7-dimethoxyxanthone, 5-hydroxy-1,6,7-trimethoxyxanthone and 2-hydroxy-1,5-dimethoxyxanthone, together with thirty-three known xanthones were isolated from the roots of Mesua ferrea L. The structures of all isolated xanthones were elucidated based on spectroscopic methods. 5-Hydroxy-1,6,7-trimethoxyxanthone and 2-hydroxy-1,5-dimethoxyxanthone were also confirmed by X-ray diffraction data. In addition, the isolated compounds were determined for antibacterial, antioxidant and cytotoxic activities. The known 1,5,6-trihydroxyxanthone showed cytotoxicity against A375, PC-3 and HaCaT cell lines with IC50 values of 5.73 µg/mL, 5.93 µg/mL and 8.94 µg/mL, respectively.

Carbazole-pyranocoumarin conjugate and two carbazole alkaloids from the stems of Clausena excavata.

A carbazole-pyranocoumarin conjugate, carbazomarin B (1), and two carbazole alkaloids, 6-methoxymukonidine (2) and 2-hydroxy-3-methoxycarbazole (3), together with 27 known compounds (4-30), were isolated from the stems of Clausena excavata. Their structures have been elucidated by spectroscopic analyses. Compound 2 showed moderate cytotoxicity to HuCCA-1, MOLT-3 and HepG2 cancer cell lines with IC50 values of 15.09-28.50 µg/mL, but none to A549 cell line. Heptaphylline (6) and nordentatin (23) were found to show moderate cytotoxic activity against HepG2 cell line with IC50 values of 12.33 and 11.33, respectively, while clausine K (27) exhibited strong cytotoxicity with IC50 value of 1.05 µg/mL, better than a standard drug (etoposide, IC50 13.40 µg/mL).