Deciphering the Glycosylation Steps in the Biosynthesis of P-1894B and Grincamycin Isolated from Marine-Derived SCSIO LR32.

Recently, we re-isolated the glycosylated angucycline antibiotics P-1894B () and grincamycin () from the marine-derived SCSIO LR32 as potent antitumor agents and identified their biosynthesis gene cluster . Both P-1894B () and grincamycin () possess a trisaccharide and a disaccharide moiety comprised of five deoxysugars. In this work, three genes encoding glycosyltransferases (GcnG1, GcnG2, and GcnG3) responsible for the assembly of deoxysugars into angucycline aglycone were identified from the biosynthesis gene cluster .

Characterization of the Aminosugar Biosynthetic and Regulatory Genes of Vicenistatin in -Associated SCSIO Mla-L010.

Vicenistatin () is a potent polyketide antitumor antibiotic composed of a 20-membered macrolactam core appended to a unique aminosugar, vicenisamine. In this study, vicenistatin was isolated and its biosynthetic gene cluster identified from -associated SCSIO Mla-L010. A set of five genes, , , , , and , was confirmed to be involved in the biosynthesis of the aminosugar by gene inactivations.

Elucidation of the Tailoring Steps in Julichrome Biosynthesis by Marine Gastropod Mollusk-Associated SCSIO 054.

The biosynthetic gene cluster governing the production of antibacterial julichromes was identified from marine gastropod mollusk-associated SCSIO 054. Post-PKS assembly/tailoring enzymes JuiL, JuiM, JuiI, and JuiN represent key assembly enzymes. JuiL serves as a ketoreductase.

Julichrome Monomers from Marine Gastropod Mollusk-Associated Streptomyces and Stereochemical Revision of Julichromes Q and Q.

Two julichrome monomers, julichromes Q (1) and Q (2), along with five known julichromes (Q , Q , Q , Q , Q , 3-7) and four known anthraquinones (chrysophanol, 4-acetylchrysophanol, islandicin, huanglongmycin A, 8-11), were isolated from the marine gastropod mollusk Batillaria zonalis-associated Streptomyces sampsonii SCSIO 054. This is the first report of julichromes isolated from a marine source. Extensive dissection of 1D and 2D NMR datasets combined with X-ray crystallography enabled rigorous elucidation of the previously reported configurations of julichrome Q (4) and related julichrome Q (5); both of the configuration at C(9) needs to be revised.

New Borrelidins from Onchidium sp. Associated Streptomyces olivaceus SCSIO LO13.

Borrelidins M-O (1-3), along with four previously known family members (4-7), were isolated from marine pulmonated mollusks Onchidium sp. associated Streptomyces olivaceus SCSIO LO13. The structures of 1-3 were elucidated by extensive spectral analyses of HR-ESI-MS, 1D and 2D NMR data.

Abyssomicin Monomers and Dimers from the Marine-Derived Streptomyces koyangensis SCSIO 5802.

Three new abyssomicin monomers designated neoabyssomicins D (1), E (2), and A2 (3) and the two dimeric neoabyssomicins F (4) and G (5) were discovered from the marine-derived Streptomyces koyangensis SCSIO 5802, and their structures rigorously elucidated. Neoabyssomicin D (1) possesses an unprecedented 8/5/5/7 ring skeleton, the biosynthesis of which (as well as 2) is proposed herein. Additionally, dimeric agents 4 and 5 were found to be active against methicillin-resistant Staphylococcus aureus and vesicular stomatitis virus, respectively.