Cyclo(Tyr-Gly)

Microbial degradation of 2,5-diketopiperazines.[Reference: WebLink]

Studies in Organic Chemistry, 1998, 53(98):167-171.

METHODS AND RESULTS:
Enrichment culture of soil samples with cyclo(Gly-Gly) and cyclo(Gly-l-Tyr) as a carbon and/or a nitrogen source resulted in the isolation of Arthrobacter sp. 1-3-1 and the coryneform rod bacterium, strain T-1-3-Y, as the bacteria which most highly assimilated cyclo(Gly-Gly) and cyclo(Gly-l-Tyr), respectively. Both bacteria had the enzyme activity hydrolyzing DKPs intracellularly in contrast to the extracellular cyclo(Gly-Gly) hydrolase reported previously. The cells of Arthrobacter sp. 1-3-1 degraded all diketopiperazines tested, including cyclo(Gly-Gly), cyclo(Gly-l-Ala), cyclo(Gly-l-Val), cyclo(Gly-l-Leu), cyclo(Gly-l-Ile), cyclo(Gly-l-Met), cyclo(Gly-l-Phe), cyclo(Gly-l-Tyr)(Cyclo(Tyr-Gly)), cyclo(l-Ala-l-Tyr), cyclo(l-Val-l-Tyr), cyclo(l-Leu-l-Tyr), cyclo(l-Tyr-l-Tyr), cyclo(l-Phe-l-Leu), cyclo(Gly-d-Ala), and cyclo(Gly-d-Leu). On the other hand, the degradation of d-amino acid-containing DKPs or cyclo(Gly-Gly) by the cells of the strain T-1-3-Y were detected hardly or not at all, respectively.
CONCLUSIONS:
From the result that DKP hydrolase in the strain T-1-3-Y had a higher stereospecificity than that in Arthrobacter sp. 1-3-1, the diversity of DKP hydrolases were found to be in nature.

Chinese Journal of Antibiotics, 2005-08.

Antitumor components from marine actinomycete 11014: I. Cyclic dipeptides.[Reference: WebLink]

METHODS AND RESULTS:
To explore the antitumor active components in fermentation of a marine actinomycete 11014, 13 cyclic dipetides were isolated and purified by using solvent extraction, silica gel column and preparation HPLC. The separation procedure was guided by a bioassay using tsFT210 cell lines. By means of physicochemical properties and spectral analysis, their structures were respectively determined as: cyclo-(Leu-Ala), cyclo-(Leu-Gly), cyclo-(Ile-Ala), cyclo-(Val-Ala), cyclo-(Ala-Phe), cyclo-(Phe-Gly), Cyclo(Tyr-Gly), cyclo-(Pro-Tyr), cyclo-(Pro-Phe), cyclo-(4-hydroxyl-Pro-Phe), cyclo-(4-hydroxyl-Pro-Leu), cyclo-(Pro-Val), cyclo-(Pro-Leu). The antitumor activities of these compounds were firstly assayed by sulfo rhodamine B method.
CONCLUSIONS:
Cyclo-(4-hydroxyl-Pro-Phe) showed cytotoxicity against tsFT210 cell lines with inhibitory rate of 48. 3% at the concentration of 5 μg/ml.