Triterpenes from 3-amyrin

Collagenase production and release are partly responsible for the joint destruction that characterises human rheumatoid arthritis. Triterpenes from the lupane and a-amyrin groups have been studied in vitro to examine their effects on the release of the arthritic joint degradative enzyme collagenase using the rat osteosarcoma. This test and the rat synovial granuloma of adjuvant arthritis are similar both models are based on connective tissue tumours with bone-invasive properties. The pentacyclic triterpenes assayed have been shown to possess general antiproteolytic effects that can explain the anti-arthritic effects in adjuvant arthritis in rats [71,103]. 

Sterols and triterpenes (P-amyrin, P-sitos-terol, lupeol, stigmasterol, viscin, hetulinic acid, oleanolic acid, and ursolic acid), ° fatty acids (oleic, linoleic, palmitic, and stearic acids),and an acyclic monoterpene glycoside (2,6-dimethylocta-2,7-diene-1,6-diol 4-0-apiosylglucoside) have recently been isolated from mistletoe. ... 

Agata, L, E. j. Corey, A. G. Hortmann, J. Klein, S. Proskow, and J. J. Ursprung Oxidative Rearrangements of Pentacyclic Triterpenes. A Method for the Synthesis of Certain Naturally Occurring Triterpenes from a- and p-Amyrin. J. Organ. Chem. (USA) 30, 1698(1965). 

The use of HMDS as a derivatization reagent in the analysis of triterpenoid resins has been less explored. The TMS derivatives of triterpenoids bearing hydroxyl groups [a-amyrine, p-amyrine and hop-22(29)-en-3p-ol] have been identified in the triterpenic fraction of Burseraceae resins, thus demonstrating that HMDS combined with Py-GC/MS is effective in the derivatization of triterpenoid compounds [59]. However, the range of structures that can be fully derivatized and detected must be extended and, in order to get comprehensive results comparable with those coming from the well assessed off-line GC/MS procedures, general improvements in the on-line trimethylsilylation-pyrolysis method are needed. 

Overall, however, the immensity of temperate land corresponds to a most various secondary metabolic production, different from that of tropical land. The most renowned alkaloids belong to the morphine class (Chart 6.2.A1), and, in combination with isoprenoids, to the ergot and triterpene classes (Chart 6.2. A2). Prominent in the peptides are the cyclosporins (the first of which was isolated from a fiingus collected in Norway), streptogramins, and P-lactams (Chart 6.2.P). The isoprenoids are represented by pyrethrin monoterpenes, cedrane sesquiterpenes, ginkgolide and taxane diterpenes, ophiobolane sesterterpenes, and arborane and amyrin-like triterpenes (Chart 6.2.1). In the polyketides, epothilones, recently discovered from Myxobacteria, and the long known rapamycin, are two prominent classes of macrolides (Chart 6.2.FA/PO/C). 

There are several natural non-combustion sources of PAHs. A study in 1980 by Wakeham [43] concluded that phenanthrene could be created by the dehydrogenation of steroids, retene could be produced by the diagenesis of abietic acid, and alkyl chrysenes could form from the degradation of the pentacyclic triterpenes alpha- and beta-amyrin, which are components of higher plant waxes. In this section we will look at the natural non-combustion sources of retene and perylene and how these sources might impact the Great Lakes. 

Although previous workers have suggested bacterial synthesis as a possible source of biogenic PAHs in modem sediments, Hase and Hites (1976) have shown that bacteria more likely only bioaccumulate them from the growth medium. Anaerobic aromatization of tetracyclic triterpenes appeared to have been demonstrated by Lohmann et aL (1990) by incubating radiolabeled j8-amyrin. 

Triterpenes not belonging to cycloartane series, as a-amyrin and P-amyrin, have been isolated from Aglycyphyllos [165]. From A. complanatus has been identified a new /i-coumaroyl derivative, named 11-0-/ -coumaroylnepecticyn, Fig. (3) [98,272]. 

P-Sitosterol and stigmasterol are the common steroids in the genus. So far only few common triterpenes such as friedelin (207), e/ /-fnedelinol (208), a-amyrin (204), P-amyrin (205), a-amyrin acetate (206), taraxasterol (213), lupeyl acetate (209), magnificol (210) were isolated from Tanacetum species. However, T. sinaicum afforded unusual new malabaricane type triterpenoids 3p-acetoxymalabarican-14(26),17E,21-triene (211) and 3-oxo-malabarica-14(26),17E,21-triene (212) (Table 1). 

Besides typical plant polysaccharides, Py-MS was also applied for the study of certain plant glycosides [65] from the group of p-amyrine (cyclic triterpenes) such as ... 

Rao et al. (52) isolated the novel triterpenoid, hyptadienic acid from the aerial part of H. suaveolens. This was the first report of a naturally occurring A-ring contracted triterpene outside the lupane series. Triguna et al. (67) isolated the new natural triterpenoid, 3y -hydroxylup-12-en-28-oic acid, from the roots of H. suaveolens in addition to a- and yff-amyrin. 

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