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Dandamycin and chandrananimycin E, benzoxazines from Streptomyces griseus
Emma C Barnes1, Patricia Bezerra-Gomes1, Markus Nett1
1Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.
The Journal of Antibiotics
|February 19, 2015
Summary
Two novel benzoxazines, chandrananimycin E and dandamycin, were discovered in Streptomyces griseus. Their unique structures show that modifications to phenoxazinone ring systems reduce biological activity.
Area of Science:
- Microbiology
- Natural Product Chemistry
- Pharmacology
Background:
- Streptomyces griseus is known for producing diverse secondary metabolites.
- Phenoxazinone compounds are frequently reported natural products, but phenoxazines are rarer.
- Novel carbon substitution at N-10 and unique cyclopentene-containing ring structures are of significant chemical interest.
Purpose of the Study:
- To isolate and characterize new benzoxazine natural products from Streptomyces griseus.
- To investigate the biological activities of the novel compounds, chandrananimycin E and dandamycin.
- To compare the structure-activity relationships of these novel compounds with known phenoxazinones.
Main Methods:
- Isolation and purification of compounds from Streptomyces griseus (HKI 0545) culture.
- Structure elucidation using spectroscopic methods.
- In vitro antiproliferative and cytotoxic assays using HUVEC and HeLa cells.
Main Results:
- Two new benzoxazines, chandrananimycin E (1) and dandamycin (2), were successfully isolated and characterized.
- Chandrananimycin E exhibited moderate antiproliferative activity against HUVEC cells (GI50 35.3 μM) and weak cytotoxicity against HeLa cells (CC50 56.9 μM).
- Dandamycin showed no significant antiproliferative or cytotoxic activity against the tested cell lines.
Conclusions:
- Chandrananimycin E and dandamycin represent unique additions to the secondary metabolome of Streptomyces griseus.
- The study suggests that alterations in the core ring systems of phenoxazinones, as seen in compounds 1 and 2, can diminish their biological activity.
- These findings contribute to the understanding of phenoxazinone-derived metabolites and their structure-activity relationships.
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