Clinical Medical College & Affiliated Hospital, Chengdu University, Chengdu 610106, China.
School of Pharmacy, Chengdu University, Chengdu 610106, China.
J Nat Prod. 2022 Sep 23;85(9):2217-2225. doi: 10.1021/acs.jnatprod.2c00658. Epub 2022 Sep 5.
Neocyclomorusin (), a natural bioactive pyranoflavone mainly isolated from plants of the Moraceae family, was synthesized for the first time using a Friedel-Crafts reaction, a Baker-Venkataraman (BK-VK) rearrangement, a selective epoxidation, and a novel S2-type cyclization as the key steps. The present protocol was also successfully applied for the total synthesis of oxyisocyclointegrin (). Structurally related natural products morusin () and cudraflavone B () were also prepared. We investigated the antibacterial activities of these natural compounds against both Gram-negative and Gram-positive strains. The prenylated flavones, morusin () and cudraflavone B (), showed comparable activity to ampicillin and kanacycin A against . Both morusin () and cudraflavone B () showed better antibacterial activities than ampicillin against the Gram-positive bacteria and . Both neocyclomorusin () and oxyisocyclointegrin () displayed disappointing antimicrobial activities against , , , and strains.
新环桑辛素（）是一种天然生物活性吡喃黄酮，主要从桑科植物中分离得到，本文首次采用傅克反应、贝克-文卡特拉曼（BK-VK）重排、选择性环氧化和新型 S2 型环化反应作为关键步骤进行合成。该方案还成功地应用于氧异环整合素（）的全合成。结构相关的天然产物桑辛素（）和 cudraflavone B（）也被制备。我们研究了这些天然化合物对革兰氏阴性和革兰氏阳性菌株的抗菌活性。这些烯基化黄酮，桑辛素（）和 cudraflavone B（），对显示出与氨苄西林和卡那霉素 A 相当的活性对。桑辛素（）和 cudraflavone B（）对革兰氏阳性菌和的抗菌活性均优于氨苄西林。新环桑辛素（）和氧异环整合素（）对 、 、 和 菌株的抗菌活性均令人失望。
