Three new diterpenoids isolated from Euphorbia nematocypha Hand.-Mazz and their anti-fungal activity

• Published in: Natural product research Vol. 38; no. 5; pp. 838 - 847
• Main Authors: Li, Rong-Shuai, Xu, Zhi-Chang, Qin, Ding-Mei, Huang, Jia-Bi, Wang, Meng-Ru, Zhao, Xue-Rong, Yang, Quan-Yu, Xiao, Wei-Lie, Wang, Rui-Rui, Li, Xiao-Li
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 03.03.2024; Taylor & Francis Ltd
• Subjects: anti-fungal activity; Candida albicans; Diterpenes; Diterpenoid; Euphorbia; Euphorbia nematocypha Hand.-Mazz; Euphorbiacea; Fluconazole; Fungi; Fungicides; Synergistic effect; Euphorbia nematocypha Hand.-Mazz; Diterpenoid; Euphorbiacea; anti-fungal activity
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2023.2207134

Three new diterpenoids, named nematocynine A-C (1-3), together with twelve known compounds (4-15) were isolated from the aerial part of Euphorbia nematocypha Hand.-Mazz (Hereinafter referred to E. nematocypha). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. In addition, all the compounds were tested for their anti-candida albicans activities used alone or in combination with fluconazole against sensitive strain and resistant strain in vitro. Wherein only compound 11 shows weak activity against candida albicans resistant strain (MIC 50 = 128.15 μg/mL) when used alone. Compounds 1, 4, 7, 8, 9, 10, 12, 13 and 15 in combination with fluconazole showed potent anti-fungal activities (MIC 50  = 15 ± 5 μg/mL, FICI = 0.05 ± 0.04) against the Candida albicans resistant strain SC5314-FR. The synergistic effects were weaker against the Candida albicans resistant strain SC5314-FR when the compounds 2, 3, 5 and 14 were combined with fluconazole (FICI = 0.16 ± 0.06).