Triterpenoid hydrocarbons

The chemical composition of birch bark tar is dependent on the temperature at which tar is produced. In producing simulated tars in the laboratory for comparison with an adhesive used to repair a Roman jar from Stan wick, Charters et al. (1993) found that tars prepared at 350 °C displayed an increase in triterpenoid hydrocarbons as well as unresolved components presumably resulting from pyrolysis, although the precise nature of these molecules has not been elucidated. Binder et al. (1990) and Charters et al. (1993) also report the presence of allobetul-2-ene [Structure 7.24] in aged birch bark tars. Since this molecule has not been reported in extracts from fresh birch bark, it could be formed during heating to produce the tar (Regert et al., 2003). 

Trendel JM, Lohmann F, Kintzinger JP, Albrecht P, Identihcation of the des-A-triterpenoid hydrocarbons occurring in surface sediments. Tetrahedron 45 4457— 4470, 1989. 

Twenty-three triterpenoid hydrocarbons isolated from ferns were screened [67]. The following eight exhibited strong inhibitory effects at lxlO2 mol ratio compound/TPA with >80% viability of Raji cells [67]. They are multiflor-8-ene (220 45%), multiflor-9(ll)-ene (228 41%), taraxastane (237 43%), taraxerane (241 37%), glutin-5(10)-ene (244 52%), hop-17(2l)-ene (275 51%), neohop-13(18)-ene (277 37%), and neohop-12-ene (278 37%). It should be mentioned that the inhibitory... 

Kimble B. (1972) The geochemistry of triterpenoid hydrocarbons. PhD Thesis, University of Bristol, 302pp. 

The allylic pyrophosphate (2.23), formed in the above reaction, then reacts with TPN-H. This is a coenzyme which is similar to NADPH and, like NADPH, serves as a hydride anion donor. The hydride ion adds to the newly formed double bond, displacing it in the direction of the pyrophosphate group, which is then lost by cleavage of the carbon-oxygen bond to produce squalene. Squalene is a triterpenoid hydrocarbon containing six double bonds and a tail-to-tail fusion in the centre of the molecule. It occurs widely in nature, shark liver oil being a particularly rich source. 

Cy denes from terrestrial origin Cyclic di- and triterpenoid hydrocarbons occur in significant amounts only in higher plants and are therefore potential markers for terrigenous plant lipids. Many compounds with various structures have been isolated from terrestrial and marine sediments and described (among others Streibl and Herout, 1969 Albrecht and Ourisson, 1971 Dastillung et al., 1977 Simoneit, 1977b, c). 

Many kinds of pentacyclic triterpenoid hydrocarbons have been isolated from ferns by Ageta and his colleagues [60-62]. Because any biological activity of these triterpenoid hydrocarbons has not been reported, the primary screening test of a part of these triterpenoid hydrocarbons (144 -161) was also carried out utilizing a short-term in vitro assay on EBV-EA activation [29]. 

Of these triterpenoid hydrocarbons, almost compounds exhibited strong inhibitory effects on EBV-EA activation at 1 x lO and 5 x 10 mol ratio/TPA except compounds 149 and 153 as shown in Table 14. Especially, hop-17(21)-ene (145), isolated from the rhizomes of Polypodium nipponica, P. formosanum and P. vulgare, showed the most significant inhibitory effects at each concentration (more than 75%, 50% and 30% at 5 x 10, 1 x 10 and 1 x 10 mol ratio/ TP A, respectively). 

The green microalga B. braunii grows as colonies of individual cells held together by a colony matrix that contains a large mixture of liquid hydrocarbons. B. braunii is further classified into four races namely races A, B, L, and S, depending on the type of hydrocarbons synthesized. The B race produces triterpenoid hydrocarbons, squalene (Figure 2.7) and botryococcene, both of which are putative condensation products of farnesyl diphosphate as the major matrix components. ... 

Metzger, P., M. David, and E. Casadevall Biosynthesis of triterpenoid hydrocarbons in the B race of the green alga Botryococcus braunii. Sites of production and nature of the methylating agent. Phytochemistry 26, 129 (1987). 

Casadevall, E., P. Metzger, and M.-P. Puech Biosynthesis of triterpenoid hydrocarbons in the alga Botryococcus braunii. Tetrahedron Letters 25, 4123 (1984). 

Bottari, F., A. Marsili, I. Morelli, and M. Pacchiani Aliphatic and Triterpenoid Hydrocarbons from Ferns. Phytochem. 11, 2519 (1972). 

Arai, Y., K. Masuda, and H. Ageta Fern Constituents Eupha-7,24-diene and (20R)-Dammara-13(17),24-diene, Tetracyclic Triterpenoid Hydrocarbons Isolated from Polypodium Species. Chem. Pharm. Bull. (Japan) 30, 4219 (1982). 

Masuda, K., K. Shiojima, and H. Ageta Fern Constituents. A New Triterpenoid Hydrocarbon, 19aH-lup-20(29)-ene, from Lemmaphyllwn microphyllum. 107th Annual Meeting of the Pharmaceutical Society of Japan, Kyoto, Apr. 1987, Abstracts of Papers, p. 340. 

Ageta, H., K. Iwata, and S. Natori A Fern Constituent, Fernene. A Triterpenoid Hydrocarbon of a New Type. Tetrahedron Letters 1963, 1447. 

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