Antimalarial 5,6-Dihydro-α-pyrones from Cryptocarya rigidifolia: Related Bicyclic Tetrahydro-α-Pyrones Are Artifacts
Antimalarial 5,6-Dihydro-α-pyrones from Cryptocarya rigidifolia: Related Bicyclic Tetrahydro-α-Pyrones Are Artifacts
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DOI：
10.1021/acs.jnatprod.5b00187
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发表时间：
2015-06-01
影响因子：
5.1
通讯作者：
Kingston, David G. I.
中科院分区：
文献类型：
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作者：
Liu, Yixi;Rakotondraibe, Harinantenaina;Kingston, David G. I.
在抗疟生物测定指导下，对硬叶厚壳桂（樟科）根材的乙醇提取物进行分馏，分离出五种新的 5,6-二氢-α-吡喃酮 Cryptorigidifoliols A-E (1-5) 和六种双环四氢-α-吡喃酮衍生物 Cryptorigidifoliols F-K （6-11）。所有化合物的结构解析都是在光谱数据解释和化学衍生化的基础上进行的，并通过NOESY、电子圆二色性(ECD)和α-甲氧基苯乙酰基(MPA)衍生物的H-1 NMR分析确定了相对构型和绝对构型。双环四氢-α-吡喃酮衍生物被鉴定为5,6-二氢-α-吡喃酮在硅胶存在下酸催化分子内迈克尔加成的产物。结构-活性关系研究表明，α，β-不饱和羰基部分的存在对于有效的抗疟活性并不是必需的。
Antimalarial bioassay-guided fractionation of an EtOH extract of the root wood of Cryptocarya rigidifolia (Lauraceae) led to the isolation of the five new 5,6-dihydro-alpha-pyrones cryptorigidifoliols A-E (1-5) and the six bicyclic tetrahydro-alpha-pyrone derivatives cryptorigidifoliols F-K (6-11). The structure elucidations of all compounds were made on the basis of the interpretation of spectroscopic data and chemical derivatization, and the relative and absolute configurations were determined by NOESY, electronic circular dichroism (ECD), and H-1 NMR analysis of alpha-methoxyphenylacetyl (MPA) derivatives. The bicyclic tetrahydro-alpha-pyrone derivatives were identified as products of acid-catalyzed intramolecular Michael addition of the 5,6-dihydro-alpha-pyrones in the presence of silica gel. A structure-activity relationship study suggested that the presence of an alpha,beta-unsaturated carbonyl moiety is not essential for potent antimalarial activity.