Structural Requirements for the Antifungal Activities of Natural Drimane Sesquiterpenes and Analogues, Supported by Conformational and Electronic Studies
作者:Marcos Derita、Iván Montenegro、Francisco Garibotto、Ricardo Enriz、Mauricio Fritis、Susana Zacchino
DOI:10.3390/molecules18022029
日期:——
Seventeen drimanes including polygodial (1), isopolygodial (2), drimenol (3) and confertifolin (4) obtained from natural sources and the semi-synthetic derivatives 5–17 obtained from 1–3, were evaluated in vitro for antifungal properties against a unique panel of fungi with standardized procedures by using two end-points, MIC100 and MIC50. A SAR analysis of the whole series, supported by conformational and electronic studies, allowed us to show that the Δ7,8 -double bond would be one of the key structural features related to the antifungal activity. The MEPs obtained for active compounds exhibit a clear negative minimum value (deep red zone) in the vicinity of the Δ7,8 -double bond, which is not present in the inactive ones. Apart of this negative zone, a positive region (deep blue) appears in 1, which is not observed either in its epimer 2 nor in the rest of the active compounds. The LogP of active compounds varies between 2.33 and 3.84, but differences in MICs are not correlated with concomitant variations in LogP values.
包括多神烯(1)、异多神烯(2)、神烯醇(3)和聚合萜(4)在内的十七种天然来源的化合物,以及从1-3合成的半合成衍生物5-17,进行了体外抗真菌活性评估,使用了标准化程序和两个终点(MIC100和MIC50)对一组特定真菌进行了测试。通过构象和电子研究支持的整个系列SAR分析表明,Δ7,8-双键可能是与抗真菌活性相关的关键结构特征。活性化合物的MEP在Δ7,8-双键附近显示出明显的负值最小值(深红区域),而在无活性化合物中没有出现。除了这个负区,1中出现了一个正区域(深蓝),而在其对映体2及其他活性化合物中则未观察到。活性化合物的LogP值在2.33到3.84之间变化,但MIC的差异与LogP值的相关变化并不相符。