Gambogic acid

CambahoLz, Camballiolz, n. camwood. Cambogiasaure, /. gambogic acid, camentieren. zementieren. camoufUeren, v.t. camouflage. 

Professor Yates research, reported in over 200 papers, covered a remarkably wide range. He established the structures of complex natural products, such as mangostin, shellolic acid, haplophytine, and the fecapentaenes. He was successful in synthesizing such complex natural products as gambogic acid, various bridged-ring steroids, and cedrene. 

Most of the natural 2,2-dialkylchromenes arc derived from a single C5 isoprenoid chain (3, R = R = Me). Recently, however, some poly-isoprenoid cliromencs have been isolated gambogic acid (13),74 flemingins (14,)75 cannabichromene (15) and cannabichromenic acid... 

A gum resin obtained from G. hanburyi, gamboges, consists mainly of resin (71.6— 74.2%), gum (21.8-24%), moisture (4.8%), traces of starch and woody fibre. The resin has the nature of an acid (gambogic acid) and is the active principle of the gum. Its specific gravity is 1.221. It forms soluble salts with alkalis and insoluble precipitates... 

When the chrornene has a side chain with a double bond in a suitable position, acids induce an intramolecular cyclization. Thus for gambogic acid and cannabichromene the simplest product (68) comes from attack of the olefin on the benzylic carbonium ion [Eq. (21)]. 

The isomeric products of the xanthone synthases are the precursors of the majority of plant xanthones (77). This class of secondary metabolites also includes prenylated compounds with high pharmaceutical potential. Gambogic acid is a bridged polycyclic derivative that induces apoptosis independent of the cell cycle through a novel mechanism of caspase activation (22). Rubraxanthone inhibits methicillin-resistant strains of Staphylococcus aureus 23). Its activity compares to that of the antibiotic vancomycin. Bioactive complex benzophenone derivatives may serve as potential lead compounds for designing drugs. Synthetic approaches to these fascinating structures have recently been developed 24,25). 

Gambogic acid derivatives Activators of caspase-3 Induce apoptosis by activating caspase-3 in syngeneic prostate animal model Preclinical 101... 

Figure 1.16 Gambogic acid as a potent apoptosis inducer.

Guttifera, which grown in India, Ceylon, Siam, and East Indies. The product is a mixture consisting chiefly of a water insoluble resin (up to 80%), with a water soluble gum (up to 27%). The resin portion is chiefly gambogic acid. 

Xanthones Hydroxanthones Gambogic acid From Garcinia spp. 

Garcinia spp. G. hanburyi G. morella Guttiferae Gamboge Gambogic acid Morellic acid IsomoreDic acid Winter (1997) ... 

Yellow Gamboge a- and p-Gambogic acids C38H44O3 and C29H30O0 Gum-resin (before 1640)... 

Yateshas applied the intramolecular Diels-Alder reaction to the synthesis of the 2,<+a-ethano-2,3,4,Ua-tetrahydroxanthene system which is present in the naturally occurring compounds roorellin cind gambogic acid. The dienone 29 was generated by oxidation of the xanthene 2 , with lead tetraacetate in acrylic acid to give the desired system... 

---