Configurational Assignment of a Flexible Benzo[g]isochromene Stereodiad from Rubia philippinensis and Inhibition of Soluble Epoxide Hydrolase Activity

• Published in: Journal of natural products (Washington, D.C.) Vol. 84; no. 9; pp. 2594 - 2599
• Main Authors: Quan, Khong Trong, Park, InWha, Kim, Chung Sub, Yoshida, Wesley, Ferreira, Daneel, Thuong, Phuong Thien, Kim, Young Ho, Na, MinKyun, Oh, Joonseok
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society and American Society of Pharmacognosy 24-09-2021
• Subjects: Benzopyrans - chemistry; Benzopyrans - pharmacology; Epoxide Hydrolases - antagonists & inhibitors; Molecular Structure; Resins, Plant - chemistry; Rubia - chemistry; Vietnam; Vietnam
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/acs.jnatprod.1c00037

A new benzo­[g]­isochromene possessing a conformationally mobile moiety was identified from Rubia philippinensis. The 2D structure was established utilizing spectrometric and spectroscopic techniques with variable temperatures. The configurational investigation of the flexible moiety was investigated utilizing contemporary NMR-combined computational tools such as DP4, direct J-DP4, and DP4 Plus. The probabilities computed from DP4 Plus analysis, featuring inclusion of an additional geometry optimization process, demonstrated more conclusive probability scores among the analyses used. The configurational assignment was also supported by compositional and molecular orbital analyses. Compound 1 inhibited soluble epoxide hydrolase (IC50 = 0.6 ± 0.01 μM), an enzyme associated with cardiovascular disorders.