Two New Cyclic Tetrapeptides of Streptomyces rutgersensis T009 Isolated from Elaphodus davidianus Excrement

Two new cyclic tetrapeptides, cyclo(l‐Val‐l‐Leu‐l‐Val‐l‐Ile) (1) and cyclo(l‐Leu‐l‐Leu‐l‐Ala‐l‐Ala) (2), and 15 known compounds, cyclo(Gly‐l‐Leu‐Gly‐l‐Leu) (3), cyclo(l‐Ser‐l‐Phe) (4), cyclo(l‐Leu‐l‐Ile) (5), cyclo(l‐Tyr‐l‐Phe) (6), cyclo(Gly‐l‐Trp) (7), cyclo(l‐Leu‐l‐Tyr) (8), cyclo(Gly‐l‐Phe) (9), cyclo(l‐Phe‐trans‐4‐hydroxy‐l‐Pro) (10), cyclo(l‐Leu‐l‐Leu) (11), cyclo(l‐Val‐l‐Phe) (12), cyclo(l‐Val‐l‐Leu) (13), cyclo(l‐Ile‐l‐Ile) (14), cyclo(l‐Tyr‐l‐Tyr) (15), turnagainolide A (16), and bacimethrin (17) were isolated from the fermentation broth of Streptomyces rutgersensis T009 obtained from Elaphodus davidianus excrement. Their structures were identified on the basis of spectroscopic analysis. Meanwhile, the absolute configurations of the amino acid residues of compounds 1 and 2 were determined by advanced Marfey method. Compound 3 was obtained from a natural source for the first time. The X‐ray single crystal diffraction data of bacimethrin (17) were also reported for the first time. Compounds 1 – 17 exhibited no antimicrobial activities with the MICs > 100 μg/ml.