Sean Brady and co-workers from Rockefeller University have reported in JACS on the isolation of metatricycloene using metagenomics.
Posted by naturalproductman on June 6, 2016
Mari Yotsu-Yamashita and co-workers from Tohoku University have reported in ACIE on the biosynthesis of tetrodotoxin.
Posted by naturalproductman on May 17, 2016
Qi Zhang and co-workers from Fudan University have reported in JACS on a C3-deoxygenation pathway found in apramycin biosynthesis. A radical SAM enzyme is responsible for dehydrating the hydroxy group.
Posted by naturalproductman on April 14, 2016
Kenji Watanabe and co-workers from the University of Shizuoka have reported in ACIE on an enzyme system (PsoE (glutathione S-transferase) and PsoF (flavin-containing monooxygenase)) that involves glutathione conjugation of a polyolefinic natural product (presynerazol) to form a glutathione adduct intermediate, which in turn is oxidized to the sulfoxide (by flavin hydroperoxide) and eliminates to form a cis-olefin (synerazol).
Posted by naturalproductman on April 11, 2016
Matthias Mack and co-workers from Mannheim University have reported in ACIE on the identification of an enzyme found in the biosynthesis of roseoflavin.
Posted by naturalproductman on April 7, 2016
Jian-Min Yue and co-workers from the Chinese Academy of Sciences have reported in Organic Letters on the isolation of mannolides A-C.
Posted by naturalproductman on March 31, 2016
Seth Herzon and co-workers from Yale have reported in JACS on the synthesis of precolibactin. It’s another example of why total synthesis is important. But another interesting aspect about this natural product is that previous efforts used bioinformatics approaches to propose the thiazoline-thiazole chain – when in fact the natural product has a terminal cysteine appended where this thiazoline-thiazole chain was proposed to exist.
Posted by naturalproductman on January 18, 2016
Jianhua Ju and co-workers at the Chinese Academy of Sciences have reported in JACS on the biosynthetic origin of L-allo-isoleucine. The culprit is a PLP-enzyme.
Posted by naturalproductman on November 24, 2015
Here’s a great Nature paper from a three lab collaboration (Lixin Zhang lab at Carnegie Mellon University, Pinghua Liu lab at Boston University, and Yan Jessie Zhang lab at UT Austin) that characterized the enzyme that forms the endoperoxide-containing natural product, verruculogen. The enzyme is an alpha-ketoglutarate dependent iron containing enzyme.
What is interesting about this enzyme is that it forms a “Compound I” species (iron oxo complex), which in turn forms a tyrosine radical within the enzyme, and this tyrosine radical is what abstracts the C-H hydrogen in the starting material, fumitremorgin B. The resulting allylic radical comes together with a molecule of oxygen that in turn cyclizes to form an endoperoxide-containing radical intermediate. This radical intermediate abstracts the tyrosine hydrogen atom to reform a tyrosine radical and verruculogen.
The process of the iron-oxo intermediate abstracting a hydrogen atom from tyrosine reminds me of the way cyclooxygenase enzymes (COX1 and COX2 enzymes) work to form the endoperoxide, prostaglandin H2, from arachidonic acid. Furthermore, if you recall Michael Green’s work published in Science last year, there was a cytochrome P450 enzyme that also removes a hydrogen atom from a nearby tyrosine residue to form a tyrosine radical.
Posted by naturalproductman on October 21, 2015
Jiri Janata and co-workers from ASCR in the Czech Republic have reported in Chemical Science on the identification of the enzyme, LmbF, in the biosynthesis of lincomycin.