Friedelane triterpene

Friedelin (friedelane triterpene) Ceratopetalum petalum (Cunoniaceae), Quercus suber (Fagaceae) [cork], Viola odorata (Violaceae), lichens PKA... 

Kotalagenin 16-acetate (friedelane triterpene) Salacia oblonga (Gelastraceae) [root] AR (rat lens) (-100)... 

Fig. 13. Synthesis of a Friedelane Triterpene with a 24-Hydroxy-3-oxo-hemiacetal Group...

The friedelane triterpene (Compund 4) was isolated from the bark of the Camerounian rainforest tree Phyllobotryon spathulatum (10) using the separation process in Table 4. 

Morikawa, T. Kishi, A. Pongpiriyadacha, Y. Matsuda, H. Yoshikawa, M. Structures of new friedelane-type triterpenes and eudesmane-type sesquiterpene and aldose reductase inhibitors from Salacia chinensis. J. Nat. Prod. 2003, 66, 1191-1196. 

Kishi A, Morikawa T, Matsuda H, Yoshikawa M. (2003) Structures of new friedelane- and norfriedelane-type triterpenes and pPolyacylated endes-mane-type sesquiterpene from Salacia chinensis Linn. S. prinoides DC., Hippocrateaceae) and radical scavenging activities of principal constituents. Chem Pharm Bull 51 1051-1055. 

TABLE VIII. FRIEDELANE TYPE SKELETON TRITERPENES... 

Friedelanes are the most frequently triterpenes isolated from Celastraceae. The co-occurrence of friedelanes and quinonemethides in several species, both in whole plants and cell cultures, has led to propose a biogenetic relationship between these two types of triterpenoids [17,21], Fig. (1). 

Oleanes comform the other group of triterpenes found in Celastraceae that- with friedelanes- are the most common skeletons isolated from the family. 

The roots of S. oblonga have been extensively used for the treatment of diabetes in the Ayurvedic system of traditional Indian medicine. From the ethyl acetate soluble portion of the methanolic extract from the roots of S. oblonga Matsuda et al. isolated compound (14), a friedelane-type triterpene [42]. The methanolic extract and the ethyl acetate soluble portions were found to show inhibitory activity on aldose reductase, which is related to chronic diabetes complications such as peripheral neuropathy, retinopathy and cataracts. Compound (14) was assayed for aldose reductase rat lens inhibitory activity. It showed inhibition percentages of 21.8 % at a concentration of 30 pM and 48.2 % at a concentration of 100 pM. The activity of (14) and other terpenoids isolated from this plant could prove to be the reason for the popular use of the plant in the Ayurvedic system for the treatment of diabetes. 

Friedelin. D A-Friedooleanan-3-one friedelan-3-One, CjjHjjO mol wt 426.70. C 84,44%. H 11.81%, O 3.75%. Major triterpene constituent of cork, obtained by extraction of ground cork with ale. Isoln I strati, Ostrogo-vich, Compt. Rend, 128, 1581 (1899). Isolated also from Ceratopelalum apetalum D. Don, Cunoniaceae Jefferies, J. Chem. Soc. 1954, 473. Structure, sterochemistry Brownlie er cl, Chem. Ind. (LondonJ 1955, 1156 Kane, Stevenson, Tetrahedron 15, 223 (1961) Stevenson, J. Org. Chem. 28, 188 (1963). Total synthesis of ( )-form R. E. Ireland, D. M. Walba, Tetrahedron Letters 1976, 1071. 

Widespread reports indicate that, in addition to their anti-inflammatory role, triterpenes have other activities. Triterpenoids have been found to possess cytotoxic, antimicrobial and interesting effects on metabolism. Triterpenoids with antitumour activity include oleanane, lanostane, lupane, friedelane, hopane and quassionoid types. Glycyrrhetinic acid has been described as an antiviral, hypolipidemic and anti-atherosclerotic agent. Cucurbitacins B and E, and oleanolic acid possess a potent protective action on the liver, and ganoderic acid and its derivatives have been shown to be inhibitors of cholesterol biosynthesis. Lanostane derivatives, like suberosol, have also been found to inhibit HIV replication in H9 lymphocytes [1,3]. 

Oleanane triterpenoids are the largest group within the triterpenes and encompass a huge number of active compounds. They are structurally classified as olean-12-ene (Table 2) and ll-keto-olean-12-ene (Table 3), directly derived from the oleanane skeleton. Other modifications give rise to the D C-friedooleananes (Table 4), friedelanes (D A-friedooleananes), 24-nor-D A-friedooleananes (Table 5) and 24,30-dinor-D A-friedooleananes (Table 6). The oleananes include glycyrrhetinic acid, probably the most widely studied triterpene. 

Clarke B J, Courtney J L, Stern W 1970 Triterpenes of the friedelane series. VII. The structure of friedelan-x-one. Aust J Chem 23 1651-1654... 

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