Tolyporphins L–R: Unusual Tetrapyrroles from a <i>Brasilonema</i> sp. of Cyanobacterium

Tolyporphins L–R (2–8) have been isolated from a mixed cyanobacterium-microbial culture. The structures of tolyporphins L and M have been revised to four constitutional isomers, isolated as two mixtures of dioxobacteriochlorins (2/3 and 4/5). In contrast, tolyporphin P (6) is a fully oxidized tetrapyrrole, while tolyporphins Q and R (7 and 8) are oxochlorins. X-ray structures are reported for the first time for tolyporphins A (1), R (8), and E (9), revealing unexpected stereochemical variation within the series.托利卟啉L~R（2~8）已从蓝细菌与微生物的混合培养物中分离获得。托利卟啉L与M的结构已被修正为4种结构异构体（constitutional isomers），并以两组二氧细菌氯啉（dioxobacteriochlorins）混合物（比例为2/3与4/5）的形式被分离得到。与之相对，托利卟啉P（6）为完全氧化的四吡咯（tetrapyrrole）化合物，而托利卟啉Q与R（7、8）则属于氧代氯啉（oxochlorins）。本研究首次报道了托利卟啉A（1）、R（8）与E（9）的X射线（X-ray）晶体结构，揭示出该系列化合物中存在意料之外的立体化学差异。