Cyclo(Phe-Gly)

Discovery on antagonists of VEGFR2-CD produced by Streptomyces strain I06A-02832[Reference: WebLink]

Chinese Journal of Antibiotics,2014,6:408-12,421.

To discover antagonists of VEGFR2-CD from the fermentation broth produced by streptomyces strain I06A-02832.
METHODS AND RESULTS:
Under the guidance of ELISA assay against VEGFR2-CD, Compounds 2832 B and 2832 C were isolated and purified by combination of different column chromatographies and HPLC. The structures of compounds 2832 B and C were identified by combination of analysis of UV, IR, MS and 1D-NMR, 2D-NMR. Compounds 2832 B and 2832 C were purified and structurally identified as cyclic dipeptides, and were the same with cyclo-(Pro-Tyr) and Cyclo(Phe-Gly) respectively. Compounds 2832 B and 2832 C showed weak antagonistic activity against VEGFR2-CD by ELISA assay.
CONCLUSIONS:
They are firstly reported compounds 2832 B and 2832 C had antagonistic activity against VEGFR2-CD.

Study on the Metabolites of Mangrove Endophytic Fungus GX-3 from the South China Sea[Reference: WebLink]

Hubei Agricultural Sciences, 2013, 52 (11) :2558- 61.

METHODS AND RESULTS:
The secondary metabolite compounds of mangrove endophytic fungus GX-3 from the South China Sea were isolated by column chromatography and identified on the basis of physic-chemical constants and spectral analysis.Six metabolites were obtained and elucidated as Cyclo(Phe-Gly) (1),cyclo-(Leu-Gly)(2),Fusaric acid(3),3,6-di-sec-butyl-1,4-dihydroxypiperazine-2,5-dione(4),cyclo-(pro-leu)(5),cyclo-(Gly-Leu)(6).
CONCLUSIONS:
In the preliminary bioassay,1 showed strong inhibitory activity against KB,KBv200 with LD50 at 6.5 and 11.2 μmol/L,respectively.The six metabolites were obtained from endophytic fungus GX-3 for the first time.

Enhancement of secondary metabolites from Bacillus Licheniformis XY-52 on immune response and expression of some immune-related genes in common carp, Cyprinus carpio.[Pubmed: 25703710]

Fish Shellfish Immunol. 2015 Jul;45(1):124-31.

METHODS AND RESULTS:
This study was undertaken to isolate active secondary metabolites from immunostimulatory Bacillus Licheniformis XY-52 and evaluate their activities at 0%, 0.5%, 1.0%, and 2.0% doses supplementation with feed on immune response in common carp at weeks 1, 2, and 3. By applying chromatography techniques and successive recrystallization, two purified metabolites were obtained and identified by spectral data (mass spectrometry and nuclear magnetic resonance) as: Cyclo(Phe-Tyr) and Cyclo(Phe-Gly). The results revealed that humoral innate immune parameters (lysozyme activity, phagocytic activity and bactericidal activity) were significantly (P < 0.05) increased after feeding on the two active compounds-supplemented diet. Furthermore, administration of the two active compounds significantly (P < 0.05) up regulated IL-1β, Type 1 IFN, IFN g2b, IL10 and TNF-α gene expression. Heat shock protein 70 (HSP70) gene expression was significantly (P < 0.05) lower as compared to control group at the end of trial. Common carp fed with the two compounds had higher survival rates (69.3%) compared to the controls (32.0%) after challenged with the pathogen, Aeromonas hydrophila.
CONCLUSIONS:
The present study indicates that the two isolated active compounds could positively influence immune response and enhance disease resistance of common carp against A. hydrophila infection.

Nat Prod Commun. 2013 Dec;8(12):1753-4.

A new cyclopeptide from endophytic Streptomyces sp. YIM 64018.[Pubmed: 24555291]

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.
METHODS AND RESULTS:
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.

CONCLUSIONS:
Cyclotetrapeptides are rarely found as Streptomycete metabolites.