Triterpenes pentacyclic

Interestingly it has been shown that the geminal methyl groups at either end of squalene may retain their identity in soyasapogenol 4.40) the C-4 methyl group, but not the hydroxymethyl group, derives from C-2 of mevalonate and in lupeol 4.34) the C-22 methyl substituent again arises from C-2 of mevalonate [52, 53]. 

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B. Buchele, T. Simmet, Analysis of 12 different pentacyclic triterpenic acids from frankincense in human plasma hy high performance liquid chromatography and photodiode array detection, Journal of Chromatography B, 795, 355 362 (2003). 

R.S. Pardhy, S.C. Bhattacharyya, P Boswellic acid, acetyl P boswellic acid, acetyl 11 keto P boswellic acid and 11 keto P boswellic acid, four pentacyclic triterpene acids from the resin of Boswellia serrata Roxb, Indian Journal of Chemistry, 16B, 176 178 (1978). 

H. Budzikiewicz, J. M. Wilson and C. Djerassi, Mass spectrometry in structural and stereo chemical problems. XXXII. Pentacyclic triterpenes, J. Am. Chem. Soc., 85, 3688 3699 (1963). 

J. Karliner and C. Djerassi, Terpenoids. LVII. Mass spectral and nuclear magnetic resonance studies of pentacyclic triterpene hydrocarbons, J. Org. Chem., 31, 1945 1956 (1966). 

Baas WJ, Investigations on leaf waxes III. Pentacyclic triterpenes, r ct>-triterpenes and non-voIatile aliphatics of four Hoya species and Ficus benjamina in relation to leaf age, Acta Bot Neerlande 31 449—476, 1982. 

The betulinic acid level in the E. florida leaves increased significantly in the May, June, Jully (autumn - winter) and, September, October and November (winter) which was mainly due to the accumulation of this compound in vegetal tissue. Some authors related with the pentacyclic triterpenes, just as betulinic, acid ursolic, acid, p-amyrine and lupeol, are supposed to be toxic to insects, due to their ability to inhibit acyl chain packing in the lipid bilayers of the insect membranes [Rodriguez et al, 1997 Prades et al., 2011]. 

Prades, J, Vogler, O, Alemany, R, Gomez-florit, M. Funari, S.S Ruiz-Gutierrez, V. Barcelo, F. ((2011). Plant pentacyclic triterpenic acids as modulators of lipid membrane physical properties Biochimica et Biophysica Acta (BBA)- Biomenbranes., 1808... 

Rodriguez, S, Garda, H, Heinzen, FI, Moyna, P. (1997). Effect of plant monofunctional pentacyclic triterpenes on the d mamic and structural properhes of dipahni-toylphosphatidylcholine bilayers Chemical Physical Lipids, 89-119. 

Matsuo Y, Suzuki M, Masuda M (1995) Enshuol, a Novel Squalene-Derived Pentacyclic Triterpene Alcohol from a New Species of the Red Algal Genus Laurencia. Chem Lett 1043... 

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. 

Another similarity between vitrinite and the exinite is the pentacyclic triterpenes found in the pyrolysates. These compounds, which show the base peak at m/z = 191 in their mass... 

For many different vegetable oils there is a characteristic qualitative and quantitative distribution of the tetracyclic and pentacyclic triterpenes, and this is thus utilized as a fingerprint for their identification. These compounds are present in either the free or the esterified form. 

These two pentacyclic triterpenes are found concentrated in the skin of the olive fruit. Extraction processes employing only physical means results in an olive oil with a low concentration of the two triterpenic diols, their highest limit having been fixed at 4.5% of the overall sterol concentration for oils 1-6. Olive-residue oils obtained by organic solvent extraction of pomace contain large amounts of uvaol and erythrodiol, their official limits respectively being >4.5 and >12% for olive-residue and olive-residue refined oil (see Table 2.2). 

PASTEELS, J.M., TERMONIA, A., WINDSOR, D.M., WITTE, L., THEURING, C., HARTMANN, T., Pyrrolizidine alkaloids and pentacyclic triterpene saponins in the defensive secretions of Platyphora leaf beetles. Chemoecology, 2001, 11, 113-120. 

Although not without some synthetic challenges due to the sterically demanding and rigid framework of the pentacyclic triterpene, betulinic acid 1... 

Mahato et al., 1992 Haralampidis et al, 2002 Vincken et al, 2007). In this chapter, emphasis will be laid on the formation of sterols and steroids in plants the pathways leading to the tetra- and pentacyclic triterpenes will not be considered further. 

Cyclic Dihydroxy Compounds. Pentacyclic triterpenes in olive oil include 3p,17p-dihydroxy-12-oleanene (erythrodiol) and its parent compound uvaol, obtained largely from the epicarp and therefore characteristic of solvent extracted oils (42, 65). 

Preparations from the gum resin of Boswellia serrata have been used as traditional remedies in Ayurvedic medicine in India for inflammatory diseases (1). The gum contains substances that have anti-inflammatory properties they are pentacyclic triterpenes related to boswellic acid, which inhibit leukotriene biosjmthesis in neutrophilic granulocytes by inhibiting 5-lipoxygenase. Certain boswellic acids also inhibit elastase in leukocytes, inhibit proliferation, induce apoptosis, and inhibit topoisome-rases in cancer cell lines. 

About 130 saponins have been described in Astragalus spp. untill now. Table (2). D-xylose (xyl), D-glucose (g c), L-rhamnose (rha), L-arabinose (ara) represent the carbohydrate components of these glycosides pentoses are more frequent then hexoses. Apiose (apio), in the furanosic form, occurs only in cycloaraloside C, named also astrailienin A [140,61]. Glucuronic acid has been found only in pentacyclic triterpene saponins (as in soyasaponins). Astragalus saponins of cycloartane series... 

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