Structure, activity, synthesis and biosynthesis of aryl-C-glycosides

Abstract

The focus of this review is to highlight the structure, bioactivity and biosynthesis of naturally occurring aryl-C-glycosides. General synthetic methods and their relevance to proposed biochemical mechanisms for the aryl-C-glycoside bond formation are also presented.

Inactivation of gilGT, Encoding a C‐Glycosyltransferase, and gilOIII, Encoding a P450 Enzyme, Allows the Details of the Late Biosynthetic Pathway to Gilvocarcin V to be Delineated

“…[1,[3][4][5] In the majority of cases, natural GTs catalyze the O-glycosyltransfer steps. Only a few C-GTs involved in the biosynthesis of natural products have been characterized so far, such as, the pathogen-associated C-GT IroB [31] or UrdGT2.…”

“…Oxygenases (OXs) and glycosyltransferases (GTs) are of particular interest. [1][2][3][4][5] Gilvocarcin V (GV, Scheme 1), the principal product of Streptomyces griseoflavus Gc3592 and many other Streptomyces strains, and the most important member of the benzo[d]-naphtho[1,2-b]pyran-6-one C-glycoside anticancer antibiotics, contains a vinyl group side chain in the C8 position and a C-glycosidically linked through a photo[2+2]cyclo-addition reaction with thymine residues, [9,10] the sugar moiety is likely to play a crucial role in GV's interaction with histone H3. Thus, the key to understanding the unique mechanism of action of gilvocarcin-type anticancer drugs, is the further investigation of the nature of the DNA-GV-histone H3 complex ( Figure 1) that interrupts the DNA replication and repackaging process necessary for cell division.…”

The C-Glycosylation of Flavonoids in Cereals

“…Intriguingly UrdGT2 also O-glycosylates artificial substrates (5), confirming that in microorganisms, there are no fundamental differences in the evolutionary origins of CGTs and OGTs. However, although the enzyme chemistry of OGTs has been well described, the exact mechanism by which C-glycosylation is achieved is still poorly understood (7).…”

Brønsted Acid-Catalyzed Direct Substitution of 2-Ethoxytetrahydrofuran with Trifluoroborate Salts

“…to these methods are that they rely on the generation of unstable boron dihalide species thereby resulting in low functional group tolerance. The number of methodologies for the preparation of C-glycosides has increased tremendously over the past several decades due their presence in natural products and enzymatically stable analogs of pharmaceutical importance [17][18][19][20][21][22][23][24][25][26]. In particular, the synthesis of 2-alkenyl and 2-alkynyl tetrahydrofuran products has been relatively well explored.…”