Triterpenoids bacterial

Diploptene pentacyclic triterpenoid (17fS(//),2l f (//)-hop-2l (29)-cnc) that has been found to be a useful diagenetic biomarker for bacterial activity. 

Regarding the detection of specific biomarkers for geochemical purposes, bacterial contribution to different sediments was associated with specific compounds found in shale pyrolysates such as certain triterpenoids [73], A few applications of analytical pyrolysis to kerogen characterization were discussed in Section 14.4. 

The detection of triterpenoid compounds in extracts from Bidens pilosa may rationalize the use of this plant in traditional Egyptian medicine in the treatment of wounds and against bacterial infections of the gastrointestinal tract [211,212]. The chloroform extract gave 3-amyrin. Fig. (29), phytosterin B and P-sitosterol glucoside, while the petroleum ether extract afforded P-am5Tin, Fig. (29), phytosterin B, lupeol. Fig. (30), lupeol acetate, linolic acid and linolenic acid. The antimicrobial test was carried out to indicate an evident activity. 

As for steroids, defunctionalization of pentacyclic triterpenoids occurs during early diagenesis and reduction or aromatization later. Some bacterial degradation of triterpenols has even been observed in the leaves of... 

Sterols comprise a very important class of compounds in plant and animal systems. Bacteria and other organisms utilize cholesterol or related sterols in the synthesis and maintenance of their cell walls. True sterols are present in cyanobacteria to only a very small degree they are largely replaced with a steroid-like class of triterpenoid known as the hopanoids. The carbon frameworks of sterols and bacterial hopanoids are synthesized in essentially the same manner as other terpenes, however, the cyclization reactions to yield their polycyclic skeletons are unique. A variety of sterols and hopanoids are found in cyanobacteria and they are believed to have important cellular functions in cell wall structure and function. " As discussed in Section 2.06.5, many of the hopanoids also possess a polyalcohol chain derived from a sugar. ... 

A thus-far-unique bacterial occurrence of this compound has also been reported in Rhodopseudomonas palustris (Kleeman et al. 1990). Pentacyclic triterpenoids with an OH group on the first ring are commonly products of higher plants. 

Rohmer M, Bisseret P, Sutter B. The hopanoids, bacterial triterpenoids, and the biosynthesis of isoprenic units in prokaryotes. Progr Drug Res, 1991 37 271-285. 

Bacterial membranes frequently contain hopanoids (Scheme 9.2), triterpenoids that appear to take the place of the sterols that are typically found in the membranes of... 

Simonin, P., Jurgens, U.J., and Rohmer, M. (1996) Bacterial triterpenoids of the hopane series from the prochlorophyte ProcMorothrix hoUandica and their intracellular localization. Fur. J. Biochem., 241, 865-871. 

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