1. Three new cyclotetrapeptides isolated from Streptomyces sp. 447
Muna Ali Abdalla Nat Prod Res. 2017 May;31(9):1014-1021. doi: 10.1080/14786419.2016.1263849. Epub 2016 Dec 9.
Three new cyclotetrapeptides, named cyclo-(L-Leu-L-Glu-L-Leu-L-Glu) (1) cyclo-(L-Ile-L-Glu-L-Ile-L-Glu) (2) and cyclo-(L-Val-L-Glu-L-Val-L-Glu) (3), were isolated from Streptomyces sp. 447 obtained from endophytic actinobacteria. The producer strain was characterized as Streptomyces sp. by 16s rDNA sequencing. The structures of the three peptides were successfully assigned on the basis of 1D and 2D NMR spectroscopic and mass spectrometry analysis, while the absolute configuration of the amino acid residues was established by amino acid hydrolysis followed by derivatization and GC-MS experiments. Antimicrobial activities of the new compounds were studied.
2. A new cyclopeptide from endophytic Streptomyces sp. YIM 64018
Xueqiong Yang, Yabin Yang, Tianfeng Peng, Fangfang Yang, Hao Zhou, Lixing Zhao, Lihua Xu, Zhongtao Ding Nat Prod Commun. 2013 Dec;8(12):1753-4.
One new cyclopeptide, cyclo(L-Phe-L-Ala-L-Phe-Gly), named as vinaceuline (1) and three known cyclodipeptides, cyclo (Phe-Gly), cyclo (Phe-4-hydroxyl-Pro) and cyclo (Phe-Ile) were isolated from broth culture of endophytic Streptomyces YIM 64018 associated with Paraboea sinensis. The planar structure of the new compound was assigned on the basis of 1D and 2D NMR spectroscopic techniques, while t he a bsolute configurations of the amino acid residueswere determined by application of the advanced Marfey method. Cyclotetrapeptides are rarely found as Streptomycete metabolites.
3. Two new minor cyclopeptides from Sagina japonica (Caryophyllaceae)
Ai-qun Jia, Ning-hua Tan, Jun Zhou Fitoterapia. 2009 Apr;80(3):192-5. doi: 10.1016/j.fitote.2009.01.004. Epub 2009 Jan 23.
Two new minor cyclopeptides, named japonicin A (1), japonicin B (2), were isolated from the whole plants of Sagina japonica (Caryophyllaceae). Their structures were determined as cyclo-(Pro(1)-Pro(2)-Leu(2)-Leu(1)-Phe(2)-Pro(3)-Gly-Ser-Phe(1)) (1) and cyclo-(Pro(1)-Ile-Tyr-Asp-Pro(2)-Phe(2)-Pro(3)-Phe(1)) (2) on the basis of spectroscopic data, especially by two-dimension NMR technologies.
