Institut für Organische und Analytische Chemie, Universität Bremen, Leobener Straße 7, 28359, Bremen, Germany.
Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13 (Haus F), 81377, München, Germany.
Chemistry. 2018 Jun 18;24(34):8609-8614. doi: 10.1002/chem.201800235. Epub 2018 May 25.
Four so far unknown pyrroloquinoline alkaloids, yellow mycenaflavins A, B, and C, and the purple mycenaflavin D, have been isolated from the fruiting bodies of Mycena haematopus. The structures of these new alkaloids were elucidated by NMR spectroscopy and HRMS (ESI ). The mycenaflavins are structurally related to mycenarubins and haematopodins, which have been previously identified in M. haematopus. However, compared with other known fungal pyrroloquinoline alkaloids, the mycenaflavins contain an additional double bond within the pyrroloquinoline moiety that accounts for the yellow colour of the monomeric mycenaflavins A, B, and C. The purple mycenaflavin D is the first known dimeric pyrroloquinoline alkaloid with a C-C bridge between the two pyrroloquinoline units. Although the minor pyrroloquinoline alkaloid constituent mycenaflavin A exhibits only moderate bioactivity against the soil bacterium Azoarcus tolulyticus, the major pyrroloquinoline alkaloid constituent haematopodin B is similarly active as the antibiotic gentamicin.
迄今为止，从红色喇叭菌（Mycena haematopus）的子实体中分离出四种未知的吡咯并喹啉生物碱，分别为黄色的喇叭菌黄素 A、B、C 和紫色的喇叭菌黄素 D。通过 NMR 光谱和高分辨质谱（ESI）确定了这些新生物碱的结构。喇叭菌黄素在结构上与先前在红色喇叭菌中鉴定出的麦角菌红和血红素有关。然而，与其他已知的真菌吡咯并喹啉生物碱相比，喇叭菌黄素在吡咯并喹啉部分含有额外的双键，这解释了单体喇叭菌黄素 A、B 和 C 的黄色。紫色的喇叭菌黄素 D 是第一个已知的具有两个吡咯并喹啉单元之间 C-C 桥的二聚吡咯并喹啉生物碱。尽管微量吡咯并喹啉生物碱成分喇叭菌黄素 A 对土壤细菌 Azotobacter tolulyticus 仅表现出中等的生物活性，但主要的吡咯并喹啉生物碱成分血红素 B 的活性与抗生素庆大霉素相当。
