查看更多>>摘要：Six alkaloids peharmalines F-K, along with 14 known ones, were isolated from the aerial part of Peganum harmala L.. The structures of the isolated compounds were determined based on their HR-ESI-MS data, extensive NMR spectroscopic analyses, and ECD calculations. 3-(4-Hydroxyphenyl)quinoline exhibited potent antiproliferative activity against the HepG-2 cell lines with an IC50 value of 3.05 mu M. Norharmane displayed a moderate inhibition against A549 and HepG-2 cells with IC50 values of 16.45 mu M and 17.27 mu M, respectively.
查看更多>>摘要：Eight undescribed isostemidal alkaloids cirrhosinones A-H (1-8), along with six known isosteroidal alkaloids (9-14), were isolated from the bulbs of Fritillaria cirrhosa D. Don. Their structures were determined by HRESIMS and 2D NMR analysis, and their absolute configurations were established by X-ray analysis. Compounds 1-8 possessed a typical cevanine-type alkaloid skeleton with a hydroxyl group rarely substituted at C-24 and compounds 4-8 possessed rare 7 alpha or 7 beta-hydroxyl groups. This was the first report of both C-7 and C-24 hydroxyl groups substituted cevanine-type alkaloids. In addition, an approach for distinguishing D/E cis and trans conformations of cevanine-type alkaloids by H-1 NMR data was developed. Moreover, the correlations between the relative configurations of 3-OH, 7-OH, 22-C, 24-OH, and 25-Me and the H-1 NMR and C-13 NMR data were also summarized. Compounds 1-9 exhibited moderate NO inhibitory activities in LPS-stimulated BV-2 cells at the concentration of 40 mu M. The acetylcholinesterase inhibitory activities of compounds 1-7 and 9-10 were also evaluated and none of them showed acetylcholinesterase inhibitory activities at the concentrations of 20-80 mu M.
查看更多>>摘要：Cucurbitacin C-type cucurbitacins that are only identified in Cucumis sativus (cucumber) are, in part, responsible for the health benefits and bitter flavor. Nevertheless, detailed information about those functional ingredients in cucumber is scarce. In this study, ten cucurbitacin C analogues including seven undescribed ones have been isolated from the bitter leaves of cucumber, in which six compounds showed growth inhibition capabilities against tumor cell lines HepG2, A549, DU145 and HCT116. Intriguingly, cucurbitacin C6 and C7 exhibited a significant inhibition effect compared to the positive control taxol (IC50 = 1.86 +/- 0.17 mu M) on HepG2 cell line with IC50 values of 10.06 +/- 0.34 mu M and 4.16 +/- 0.42 mu M, respectively. The mechanism of cucurbitacin-induced apoptosis is likely down-regulating the expression of caspase-related proteins. This work enlarges the knowledge of the cucurbitacins in cucumber and highlights the importance of cucumber as a source of specialized metabolites in the food and medicinal industries.
查看更多>>摘要：Two undescribed nitrogen bridged cassane alkaloids (caesanamides A-B) and five undescribed oxygen bridged cassane diterpenoids (caesalpinins JA-JE), together with six known analogs, were isolated and identified from the seeds of Caesalpinia sappan. Their structures, including the absolute configurations, were unequivocally elucidated by the analysis of comprehensive spectroscopic data, ECD calculations, single-crystal X-ray diffraction and the CASE algorithm. Among them, caesanamides A and B represent the first examples of cassane alkaloids bearing unique ring systems of an amide bridge between C-19/C-20 incorporating a 1,3-oxazolidine (6/6/6/5/6/5) or a 7-one-1,3-oxazepine (6/6/6/5/6/7). Caesalpinin JA is an A/B cis-20-norcassane diterpenoid with a rare five-membered oxygen bridge between C-10/C-18. Biological evaluation showed that cassane alkaloids exhibited significant cytotoxicity against HepG2 cells with IC50 values of 13.48 +/- 1.07 mu M (caesanamide A), 18.91 +/- 0.98 mu M (caesanamide B), and 7.82 +/- 0.65 mu M (caesanine B). Further flow cytometry analysis revealed that caesanine B could cause GOG1 cell cycle arrest and promote apoptosis in a dose- and time-dependent manner in HepG2 cells.
查看更多>>摘要：Using chemical and spectroscopic data, this study on Brachybotrys paridiformis Maxim. ex Oliv. identified four undescribed phenylpropanoids, brachin A-C and brachoside A, together with nine other known compounds. The isolated compounds were tested for anti-hepatitis B virus activities in the HepG2.2.15 cell line. Among them, caffeic anhydride showed the most potent activity.
查看更多>>摘要：Eight undescribed guaianolides (macrocephalolides A-H) and two known analogues (parishin C, artabsinolide E) were isolated from the whole plant of Artemisia macrocephala growing in Xinjiang, China. Their structures were determined on the basis of extensive spectroscopic analysis, with absolute configurations established by comparison of experimental and calculated ECD data, as well as confirmation of single-crystal X-ray diffraction crystallography. Macmcephalolides A-B featured an unusual type of 3-oxa-guaianolide with a cyclopentenone moiety. Macrocephalolides C-E possessed a dihydro-2H-pyran acetal segment, representing an unprecedented 2, 3-secoguaianolide skeleton with 6/7/5 tricyclic ring system in natural sesquiterpenes. The X-ray crystal structures of parishin C and artabsinolide E were reported for the first time.
NSTL
Elsevier