Polyporenic acid

P. anthracophilus found on a Eucalyptus species were established at the same time. The work on eburicoic acid was carried out by Robertson in Liverpool. The elucidation of the structure of polyporenic acid A (5.161) benefited from experience gained in studies on the structure of lanosterol and on the penta-cyclic triterpenes. The identification of some structural features also showed the developing role of UV and IR spectroscopic methods in the 1950s. However, the purification of these compounds was impeded by the difficulty of separating the 8(9)-enes from the 7(8),9(ll)-dienes that often accompanied them. Initial studies on polyporenic acid A revealed the presence of a carboxylic acid, two hydroxyl groups and two double bonds, each of differing reactivity. One double bond was a terminal methylene since formaldehyde was obtained on ozonolysis whilst the other was more hindered. Typical of the tetracyclic triterpenes. 

Polyporenic acids A and C have anti-inflammatory activity and, in a bioassay for potential anti-tumour activity, suppressed the oedema induced by 12-O-tetradecanoylphorbol-13-acetate. 

Polyporanic acid, polyporenic acid A a tetracyclic triterpene carboxylic acid. A/, 486.74, m.p. 200°C, [ ]d + 74°. P a. is structurally related to 5a-lanostane (see Lanosterol). It occurs in the fungus Polypoms spp. growing on birch trees. 

The structurally related cephalosporin and helvolic acid do not appear to have the same antibacterial potency as fusidic acid [271, 336, 337] and so would not seem destined for equivalent status in medicine. Similarly the antibacterial potency of the triterpenoid antibiotics polyporenic acid A [338] and polyporenic acid C [339], like that [340] of pristimerin (LXI) [341, 342], which is one of the most highly oxidised naturally occurring pentacyclic triterpenes... 

The most potent of the triterpene acids were found to be glyc5rrhetinic acid which approached the activity shown by 2,4-dinitrophenol, polyporenic acid A and fusidic acid (LX) which exceeded the activity shown by sahcylic acid. It is considered [6] that all three acids may uncouple phosphorylation by interaction with key lysyl amino-groups which participate in mitochondrial phosphorylation. 

Piperinic acid, T1 Piperitenone oxide, T4 Piperitols, T4 Piperitone, T2 Piperitone oxide, T4 Pipitzols, T1 Pisatin, Y3 Piscidic acid, A30 Plathyterpol, T39 Platicodigenin, T45 Platydesmine, K31 Platynecine, K22 Plicatic acid, Y7 Plinols, T3 Plumericin, T16 Plumieride, T16 Pluviine, K6 Podocarpic acid, T33 Podolactones, T38 Polyether antibiotics, Yll Polyporenic acid A, T50 Ponasterone, T48 Porantherine, K29 Porphyrins, Y23 Portentol, Y15 Portulal T40 Preisocalamendiol, T22 Pretoxin, T31 Pristimerin, T45 Pristimerol, T45 Proaporphine alkaloids, K3 Proline, All Prolinol, A17 Pronuciferine, K3 19-propylthevinol, K4 Prostaglandins, Y16 Protoaphins, YIO Protoemetine, K2 Protostanes, T50... 

Poly ether antibiotics, Yll, Y6 Polyporenic acid A, TSO Polyzonimine, K8 ... 

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