A new cyclic peptide photoditritide (1), containing two rare amino acid d-homoarginine residues, was isolated from Photorhabdus temperata Meg1 after the nonribosomal peptide synthetase encoding gene pdtS was activated via promoter exchange. The structure of 1 was elucidated by HR-MS and NMR experiments. The absolute configurations of amino acids were determined according to the advanced Marfey's method after hydrolysis of 1. Bioactivity testing of 1 revealed potent antimicrobial activity against Micrococcus luteus with an MIC value of 3.0 μM and weak antiprotozoal activity against Trypanosoma brucei rhodesiense with an IC50 value of 13 μM. Additionally, the biosynthetic pathway of 1 was also proposed.

中文翻译：

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温带光子菌Meg1的光二苯甲酰胺的结构，生物合成和生物活性。

通过启动子交换激活非核糖体肽合成酶编码基因pdtS后，从光生光球菌中分离出一个新的环状肽photoditritide（1），其中包含两个罕见的氨基酸d-高精氨酸残基。通过HR-MS和NMR实验阐明了1的结构。水解1后，根据高级Marfey方法测定氨基酸的绝对构型。1的生物活性测试表明，其对黄褐微球菌的有效抗菌活性为MIC，值为MIC为3.0μM；对原生布鲁氏锥虫的抗原生动物活性较弱，其IC50值为IC50。 13微米 另外，还提出了1的生物合成途径。