1. Academic Validation
  2. Frenolicins C-G, pyranonaphthoquinones from Streptomyces sp. RM-4-15

Frenolicins C-G, pyranonaphthoquinones from Streptomyces sp. RM-4-15

  • J Nat Prod. 2013 Aug 23;76(8):1441-7. doi: 10.1021/np400231r.
Xiachang Wang 1 Khaled A Shaaban Sherif I Elshahawi Larissa V Ponomareva Manjula Sunkara Yinan Zhang Gregory C Copley James C Hower Andrew J Morris Madan K Kharel Jon S Thorson
Affiliations

Affiliation

  • 1 Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536-0596, USA.
Abstract

Appalachian active coal fire sites were selected for the isolation of Bacterial strains belonging to the class actinobacteria. A comparison of high-resolution electrospray ionization mass spectrometry (HRESIMS) and ultraviolet (UV) absorption profiles from isolate extracts to natural product databases suggested Streptomyces sp. RM-4-15 to produce unique metabolites. Four new pyranonaphthoquinones, frenolicins C-F (1-4), along with three known analogues, frenolicin (6), frenolicin B (7), and UCF76-A (8), were isolated from the fermentation of this strain. An additional new analogue, frenolicin G (5), along with two known compounds, deoxyfrenolicin (9) and UCF 13 (10), were isolated from the fermentation supplied with 18 mg/L of scandium chloride, the first example, to the best of our knowledge, wherein scandium chloride supplementation led to the confirmed production of new Bacterial secondary metabolites. Structures 1-5 were elucidated on the basis of spectral analysis and chemical modification. While frenolicins are best known for their anticoccidial activity, the current study revealed compounds 6-9 to exhibit moderate cytotoxicity against the human lung carcinoma cell line (A549) and thereby extends the Anticancer SAR for this privileged scaffold.

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