Qingqianliusus A-N, 3,4-seco-dammarane triterpenoids from the leaves of Cyclocarya paliurus and their biological activities

Fourteen previously unreported 3,4-seco-dammarane triterpenoids named Qingqianliusus A-N (1-14), along with four known 3,4-seco-dammarane triterpenoid derivatives (15-18) were isolated from the 95 % ethanol extract of the Cyclocarya paliurus leaves. Compounds 1 and 2 possess a rare 3,11-heptacyclic lactone as natural product, and several pairs of the 3,4-secodammarane triterpenoid epimers with R/S configuration at C-24 were investigated and determined in detail for the first time. Compounds 8, 11, and 14 showed good a-glucosidase inhibitory effects with IC50 values of 4.97 +/- 0.63, 7.08 +/- 0.53, and 3.76 +/- 0.77 lM, respectively. Meanwhile, compound 11 was also found potent inhibition rate of 35.83 % against COX-2, as compared with the positive control celecoxib (70.28 %). In addition, compounds 3, 7, 10, and 13 exhibited outstanding cytotoxicities against human gastric cancer cell lines (BGC-823) with IC50 values of 7.69 +/- 0.21, 8.47 +/- 0.41, 9.04 +/- 0.61, and 8.86 +/- 0.38 lM, respectively. Compounds 13 and 3 had modest activities on human colon cancer cell lines (HCT-116) with IC50 values of 8.80 +/- 0.36 and 9.45 +/- 0.93 lM, respectively. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Fourteen previously unreported 3,4-seco-dammarane triterpenoids, along with four known derivatives, were isolated from Cyclocarya paliurus leaves. Two of the compounds possess a rare lactone structure and the configurations of multiple pairs of epimers were determined for the first time. Some of the compounds demonstrated potent inhibitory effects on α-glucosidase and COX-2, as well as significant cytotoxicities against human gastric and colon cancer cell lines.