Garbractin A, a Polycyclic Polyprenylated Acylphloroglucinol with a 4,11-dioxatricyclo[4.4.2.01,5]Dodecane Skeleton from Garcinia bracteata Fruits

Xue-Ni Li; Jing Xu; Shuang Yang; Qing-Qing Li; Zheng-Yang Lu; Gui Mei; Jia-Qian Li; Guang-Zhong Yang; Xin-Xiang Lei; Yu Chen

doi:10.1021/acsomega.3c04947

Garbractin A, a Polycyclic Polyprenylated Acylphloroglucinol with a 4,11-dioxatricyclo[4.4.2.0^1,5]Dodecane Skeleton from Garcinia bracteata Fruits

ACS Omega. 2023 Aug 14;8(33):30747-30756. doi: 10.1021/acsomega.3c04947. eCollection 2023 Aug 22.

Authors

Xue-Ni Li¹, Jing Xu¹, Shuang Yang¹, Qing-Qing Li¹, Zheng-Yang Lu², Gui Mei¹, Jia-Qian Li¹, Guang-Zhong Yang^{1

3}, Xin-Xiang Lei⁴, Yu Chen²

Affiliations

¹ School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, P. R. China.
² College of Chemistry and Material Sciences, South-Central Minzu University, Wuhan 430074, P. R. China.
³ Ethnopharmacology Level 3 Laboratory, National Administration of Traditional Chinese Medicine, Wuhan 430074, P. R. China.
⁴ State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.

Abstract

Garbractin A (1), a structurally complicated polycyclic polyprenylated acylphloroglucinol (PPAP) with an unprecedented 4,11-dioxatricyclo[4.4.2.0^1,5] dodecane skeleton, was isolated from the fruits of Garcinia bracteata, along with five new biosynthetic analogues named garcibracteatones A-E (2-6). Their structures containing absolute configurations were revealed using spectroscopic data, the residual dipolar coupling-enhanced NMR approach, and quantum chemical calculations. The antihyperglycemic effect of these PPAPs (1-6) was evaluated using insulin-resistant HepG2 cells (IR-HepG2 cells) induced through palmitic acid (PA). Compounds 1, 3, and 4 were found to significantly promote glucose consumption in the IR-HepG2 cells and, therefore, may hold potential as candidates for treating hyperglycemia.