Ahmed Marwa H, Ibrahim Mohamed Ali, Zhang Jin, Melek Farouk R, El-Hawary Seham S, Jacob Melissa R, Muhammad Ilias
Nat Prod Commun. 2014 Feb;9(2):221-4.
Bioassay-guided fractionation of the chloroform soluble fraction of stem, leaf, and flower extracts of the American plant Ivesia gordonii led to the isolation of a new dimeric acylphloroglucinol, 3,3'-diisobutyryl-2,6'-dimethoxy-4,6,2',4'-tetrahydroxy-5,5'dimethyldiphenyl methane (1), to which we have assigned the trivial name ofivesinol (1), together with a known monomeric acylphloroglucinol, 1,5-dihydroxy-2-(2'-methylpropionyl)-3-methoxy-6-methylbenzene (2). The structures of the isolated compounds were characterized using 1D- and 2D- NMR spectroscopy, including COSY, HMQC, HMBC, and ROESYexperiments, as well as mass spectrometry. Ivesinol (1) showed potent activity against Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA) with IC50/MIC/MBC values of 0.10/1.25/>20 microg/mL and 0.05/0.31/>20 microg/mL, respectively (vs. IC50/MIC/MBC 0.13/0.5/1.0 microg/mL and 0.13/0.5/1.0 microg/mL of ciprofloxacin), while the corresponding monomer 2 was found to be less active. Compound 1 also demonstrated strong activity against vancomycin-resistant Enterococcus faecium (VRE) with IC50/MlC/MBC values of 0.22/1.25/>20 microg/mL, whereas the reference standard ciprofloxacin was found to be inactive against this strain. In addition, compound 2 showed moderate activity against two species of Candida and Cryptococcus neoformans, while 1 was inactive against these fungi. In order to evaluate the influence of the acyl group(s) in phloroglucinol (3) as a ligand, the mono- (4) and diacetylphloroglucinol (5) were prepared from 3, and evaluated for their in vitro SA, MRSA, and VRE activities; 2,4-diacetylphloroglucinol (5) showed potent activity, like 1, against SA, MRSA, and VRE (ATCC 700221) with IC50/MIC values of 0.3/2.5, 0.23/2.5, and 0.86/2.5 microg/mL, respectively, while 4 was inactive.
对美国植物戈登艾维草茎、叶和花提取物的氯仿可溶部分进行生物测定导向的分级分离，得到一种新的二聚体酰基间苯三酚，即3,3'-二异丁酰基-2,6'-二甲氧基-4,6,2',4'-四羟基-5,5'-二甲基二苯基甲烷（1），我们将其俗名为艾维辛醇（1），同时还得到一种已知的单体酰基间苯三酚，即1,5-二羟基-2-(2'-甲基丙酰基)-3-甲氧基-6-甲基苯（2）。使用一维和二维核磁共振光谱（包括COSY、HMQC、HMBC和ROESY实验）以及质谱对分离出的化合物结构进行了表征。艾维辛醇（1）对金黄色葡萄球菌（SA）和耐甲氧西林金黄色葡萄球菌（MRSA）显示出强效活性，其IC50/MIC/MBC值分别为0.10/1.25/>20 μg/mL和0.05/0.31/>20 μg/mL（相比之下，环丙沙星的IC50/MIC/MBC值为0.13/0.5/1.0 μg/mL和0.13/0.5/1.0 μg/mL），而相应的单体2活性较低。化合物1对耐万古霉素屎肠球菌（VRE）也表现出较强活性，其IC50/MIC/MBC值为0.22/1.25/>20 μg/mL，而参考标准环丙沙星对该菌株无活性。此外，化合物2对两种念珠菌和新型隐球菌表现出中等活性，而1对这些真菌无活性。为了评估间苯三酚（3）中酰基作为配体的影响，由3制备了单乙酰间苯三酚（4）和二乙酰间苯三酚（5），并对它们的体外SA、MRSA和VRE活性进行了评估；2,4-二乙酰间苯三酚（5）对SA、MRSA和VRE（ATCC 700221）表现出与1类似的强效活性，其IC50/MIC值分别为0.3/2.5、0.23/2.5和0.86/2.5 μg/mL，而4无活性。
