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Oh, DC, Gontang EA, Kauffman CA, Jensen PR, Fenical W.  2008.  Salinipyrones and pacificanones, mixed-precursor polyketides from the marine actinomycete Salinispora pacifica. Journal of Natural Products. 71:570-575.   10.1021/np0705155   AbstractWebsite

Chemical examination of a phylogenetically unique strain of the obligate marine actinomycete Salinispora pacifica led to the discovery of four new polyketides, salinipyrones A and B (1, 2) and pacificanones A and B (3, 4). These compounds appear to be derived from a mixed-precursor polyketide biosynthesis involving acetate, propionate, and butyrate building blocks. Spectral analysis, employing NMR, IR, UV, and CD methods and chemical derivatization, was used to assign the structures and absolute configurations of these new metabolites. Salinipyrones A and B displayed exactly opposite CD spectra, indicating their pseudoenantiomeric relationship. This relationship was shown to be a consequence of the geometric isomerization of one double bond. The phenomenon of polyketide module skipping is proposed to explain the unusual biosynthesis of the salinipyrones and the pacificanones.

Oh, DC, Williams PG, Kauffman CA, Jensen PR, Fenical W.  2006.  Cyanosporasides A and B, chloro- and cyano-cyclopenta a indene glycosides from the marine actinomycete "Salinispora pacifica". Organic Letters. 8:1021-1024.   10.1021/ol052686b   AbstractWebsite

Two structurally novel cyclopenta[a]indene glycosides, cyanosporasides A and B (1 and 2) have been isolated from the culture broth of a new species of the obligate marine actinomycete genus Salinispora. The structures and absolute stereochemistries of these compounds were determined by spectral and chemical methods. The cyanosporasides possess a new 3-keto-pyranohexose sugar as well as a cyano- and chloro-substituted cyclopenta[a]indene ring system. The cyanosporasides are proposed to be cyclization products of an enediyne precursor.

Oh, DC, Strangman WK, Kauffman CA, Jensen PR, Fenical W.  2007.  Thalassospiramides A and B, immunosuppressive peptides from the marine bacterium Thalassospira sp. Organic Letters. 9:1525-1528.   10.1021/ol070294u   AbstractWebsite

[GRAPHICS] Two new cyclic peptides, thalassospiramides A and B (1 and 2), were isolated from a new member of the marine alpha-proteobacterium Thalassospira. The thalassospiramides, the structures of which were assigned by combined spectral and chemical methods, bear unusual gamma-amino acids and show immunosuppressive activity in an interleukin-5 production inhibition assay (IC50 = 5 mu M for thalassospiramide B).

Oh, DC, Kauffman CA, Jensen PR, Fenical W.  2007.  Induced production of emericellamides A and B from the marine-derived fungus Emericella sp in competing co-culture. Journal of Natural Products. 70:515-520.   10.1021/np060381f   AbstractWebsite

Induction of the production of emericellamides A and B (1, 2), by the marine-derived fungus Emericella sp., was observed during co-culture with the marine actinomycete Salinispora arenicola. The planar structures of these new cyclic depsipeptides, which incorporate 3-hydroxy-2,4-dimethyldecanoic acid and 3-hydroxy-2,4,6-trimethyldodecanoic acid, were assigned by combined chemical and spectral methods. The absolute configurations of the amino acids, and those of the chiral centers on the side chain, were established by application of the Marfey's method, by J-based configuration analysis, and by application of the modified Mosher method. Emericellamides A and B show modest antibacterial activities against methicillin-resistant Staphylococcus aureus with MIC values of 3.8 and 6.0 mu M, respectively.

Oh, DC, Jensen PR, Fenical W.  2006.  Zygosporamide, a cytotoxic cyclic depsipeptide from the marine-derived fungus Zygosporium masonii. Tetrahedron Letters. 47:8625-8628.   10.1016/j.tetlet.2006.08.113   AbstractWebsite

Zygosporamide (1), a new cyclic pentadepsipeptide, was isolated from the seawater-based fermentation broth of a marine-derived fungus identified as Zygosporium masonii. The structure of 1, which is composed of alpha-hydroxyleucic acid and both D-and L-amino acids, was determined by combined spectral and chemical methods. Despite a simple structure, zygosporamide illustrated significant cytotoxicity in the NCI's 60 cell line panel (median GI(50) = 9-1 mu M), with highly enhanced selectivity against the CNS cancer cell line SF-268 (GI(50) = 6.5 nM) and the renal cancer cell line RXF 393 (GI(50) <= 5.0 nM). (c) 2006 Elsevier Ltd. All rights reserved.

Oh, DC, Jensen PR, Kauffman CA, Fenical W.  2005.  Libertellenones A-D: Induction of cytotoxic diterpenoid biosynthesis by marine microbial competition. Bioorganic & Medicinal Chemistry. 13:5267-5273.   10.1016/j.bmc.2005.05.068   AbstractWebsite

The induction of biosynthesis of four new diterpenoids was observed following the addition of a marine alpha-proteobacterium to an established culture of the marine-derived fungus Libertella sp. The fungal strain and the marine bacterium, cultured alone, do not produce diterpenoid metabolites. The induced diterpenoids, libertellenones A-D, are cross-conjugated ketones of the pimarane class. The libertellenones show varying levels of cytotoxicity against the HCT-116 human adenocarcinoma cell line with libertellenone D being the most potent (IC50 = 0.76 mu M). (c) 2005 Elsevier Ltd. All rights reserved.

Oh, H, Jensen PR, Murphy BT, Fiorilla C, Sullivan JF, Ramsey T, Fenical W.  2010.  Cryptosphaerolide, a Cytotoxic Mcl-1 Inhibitor from a Marine-Derived Ascomycete Related to the Genus Cryptosphaeria. Journal of Natural Products. 73:998-1001.   10.1021/np1000889   AbstractWebsite

Examination of the saline fermentation products from the marine-derived ascomycete fungal strain CNL-523 (Cryptosphaeria sp.) resulted in the isolation of cryptosphaerolide (1). The new compound is an ester-substituted sesquiterpenoid related to the eremophilane class, The structure of the new compound was assigned by spectroscopic and chemical methods. Cryptosphaerolide was found to be an inhibitor of the protein Mcl-1, a cancer drug target involved in apoptosis. It also showed significant cytotoxicity against an HCT-116 human colon carcinoma cell line, indicating that the compound may be of value in exploring the Mcl-1 pathway as a target for cancer chemotherapy.