OBJECTIVE The present report describes the enzymatic acylation of umbelliferone with different vinyl esters as acyl donors biocatalyzed by the commercial lipase Novozym® 435, and the investigation for their antibacterial activity against ATCC and clinical strains isolated from hospital infection sites. RESULTS The umbelliferone esters (1-5) were synthesized through the acylation reaction of 7-hydroxy-2H-chromen-2-one with different long chain vinyl esters catalyzed by the lipase Novozym 435. The reaction conditions were: 10% Novozym 435; tetrahydrofuran:acetone (3:1) for the reactions with acetate, propionate and butyrate vinyl esters 50-90% conversion, and (9:1) for decanoate and laurate vinyl esters 10-15% conversion; acyl donor/umbelliferone molar ratio of 10:1 and 60 °C. All the umbelliferone esters were characterized NMR and (HRMS). The antibacterial activity of the products were tested using the broth microdilution method in order to determine the minimum inhibitory concentration (MIC). The results displayed by 7-laurate and 7-decanoate-umbelliferone esters showed the highest antibacterial potential, with 1 mM inhibitory activity for ATCC 33591, a methicillin and oxacillin resistant Staphylococcus aureus strain. They were also able to inhibit gram-negative bacterial strains, such as Pseudomonas aeruginosa (MIC 0.5 mM) and Klebsiella pneumoniae (MIC 1 mM). In addition, 7-laurate- and 7-decanoate-umbelliferone esters were able to inhibit all clinical strains (MIC 1 mM; except 7-laurate-umbelliferone in which MIC 0.5 mM against 55a). CONCLUSIONS This is the first study performing the biocatalysis of umbelliferone followed by the purification of the products and the antibacterial evaluation.

中文翻译：

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通过脂肪酶介导的生物催化途径产生的具有抗菌活性的伞形酮酯

目的本报告描述了伞形酮与不同乙烯基酯作为酰基供体在商业脂肪酶 Novozym® 435 生物催化下的酶促酰化，以及它们对 ATCC 和从医院感染部位分离的临床菌株的抗菌活性的研究。结果在脂肪酶Novozym 435催化下，7-羟基-2H-色烯-2-酮与不同长链乙烯基酯酰化反应合成伞形酮酯(1-5)。反应条件为：10% Novozym 435；四氢呋喃：丙酮 (3:1) 用于与乙酸、丙酸和丁酸乙烯基酯的反应 50-90% 转化率，和 (9:1) 用于癸酸和月桂酸乙烯基酯 10-15% 的转化率；酰基供体/伞形酮摩尔比为 10:1 和 60 °C。所有伞形酮酯均通过 NMR 和 (HRMS) 表征。使用肉汤微量稀释法测试产品的抗菌活性以确定最小抑菌浓度(MIC)。7-月桂酸酯和 7-癸酸酯-伞形酮酯显示的结果显示出最高的抗菌潜力，对 ATCC 33591（一种耐甲氧西林和苯唑西林的金黄色葡萄球菌菌株）具有 1 mM 的抑制活性。它们还能够抑制革兰氏阴性细菌菌株，例如铜绿假单胞菌 (MIC 0.5 mM) 和肺炎克雷伯菌 (MIC 1 mM)。此外，7-月桂酸酯和 7-癸酸酯-伞形酮酯能够抑制所有临床菌株（MIC 1 mM；7-月桂酸酯-伞形酮除外，其中 MIC 0.5 mM 对 55a）。