Dammaran

Sapogeniiis of the dammaran type were isolated from the leaves and roots of the plant Panax no-toginseng, native to China One of these sapogeniiis has the elemental eomposition C30//52O4 and produees the set of NMR results 51. What is the strueture of the sapogenin ... 

Kuo YH, Huang HC, Yang Kuo LM, et al. New dammarane-type saponins from the galls of Sapindus mukorossi. J Agric Food Chem 2005 53 4722-4727. 

Guttiferales Dipterocarpaceae Hopea (dammar) Dammaranes (hydroxydammarenone, dammaradienol), ursanes (ursonic acid, ursonaldehyde)... 

Terebinthales Anacardiaceae Pistacia (mastic) Euphanes (masticadienonic acid, isomasticadienonic acid), oleanananes (oleanonic acid, moronic acid), dammaranes... 

Dammar resin was introduced into Europe in the nineteenth century, mainly as a paint varnish It is still used today since it has good optical properties and low acidity. It is derived from various species (the genus Hopea and Shorea of the Dipterocarpaceae family). It is characterised by tetracyclic triterpenoids of the dammarane series and contains minor amounts of pentacyclic triterpenoids of the series of olanane, ursane and hopane. It also contains a polymeric fraction named polycadinene or [S-resene. Dammar resin triterpenoids undergo oxidation with ageing, as described for the components of mastic resin. 

Figure 5.5 Norrish reaction of a triterpenoid (e.g. dammarane, oleanane or ursane type) leading to ring opening and subsequent oxidation of the ketone to the corresponding acid...

Dammar is produced by trees belonging to the Dipterocarpaceae family. It is mainly composed of triterpenoids, but it also contains a polymeric fraction based on polycadinene, a polysesquiterpene [37,38]. The main components of the triterpene fraction are compounds with a dammarane type skeleton and oleane/ursane type molecules [39,40]. 

Several studies have dealt with the problem of discriminating between mastic and dammar, and three marker compounds of mastic have been identified moronic, masticadienonic and acetyl masticadienolic acids [42], The chemical structure of (iso)masticadienonic acid and 3-0-acetyl-3-epi(iso)masticadienonic acid is characterized by a side chain, as for dammarane molecules, but with a carboxylic acid end group (Table 12.1). Under pyrolysis conditions this side chain is susceptible to cleavage as demonstrated by the presence, among the pyrolysis products of mastic, of 2-methyl-pent-2,4-dienoic acid, that perfectly matches with the chemical structure of the side chain end. In addition 3-(9-acetyl-3-epi-(iso)masticadienolic acid also loses the acetyl group and, in contrast to masticadienonic acid, is not detected at all. 

Triterpenoid saponins are synthesized via the isoprenoid pathway.4 The first committed step in triterpenoid saponin biosynthesis involves the cyclization of 2,3-oxidosqualene to one of a number of different potential products (Fig. 5.1).4,8 Most plant triterpenoid saponins are derived from oleanane or dammarane skeletons although lupanes are also common 4 This cyclization event forms a branchpoint with the sterol biosynthetic pathway in which 2,3-oxidosqualene is cyclized to cycloartenol in plants, or to lanosterol in animals and fungi. 

Ginsenosides with a few exceptions share a similar basic structure, consisting of a saturated 1,2-cyclopentanoperhydrophenanthrene (sterane or gonane) steroid nucleus. They are classified into two groups by the skeleton of aglycones, namely dammarane-type and oleanane-type. Ginsenosides... 

FIGURE 1.4 Proposed biosynthetic route for the biosynthesis of (A) squalene oxide (squalene-2,3-oxide) via the isoprenoid pathway and (B) triterpene saponins of the dammarane-type and oleanane-type from squalene oxide. PP, diphosphate group GPS, geranyl phosphate synthase FPS, farnesyl phosphate synthase NADPH, nicotinamide adenine dinucleotide phosphate. 

As described above, the cyclization of squalene oxide is a biosynthetic branching point not only for phytosterols and triterpenes but also for dammarane- and oleanane-type ginsenosides. In ginseng, the enzyme... 

Besso, H., Kasai, R., Saruwatari, Y., Fuwa, T., and Tanaka, O. (1982). Ginsenoside-Raj and ginsenoside-Ra2, new dammarane saponins of ginseng roots. Chem. Pharm. Bull. 30, 2380-2385. 

Cui, J.-F., Eneroth, P., Bruhn, J. G., Arihara, S., and Yoshikawa, K. (1998). Alkaline cleavage of gypenosides and characterization of dammarane-type aglycones by gas chromatography-mass spectrometry. Phytochem. Anal. 9, 128-133. 

Dou, D.-Q., Chen, Y.-J., Liang, L.-H., Pang, F.-G., Shimizu, N., and Takeda, T. (2001). Six new dammarane-type triterpene saponins from the leaves of Panax ginseng. Chem. Pharm. Bull. 49, 442-446. 

Komakine, N., Okasaka, M., Takaishi, Y., Kawazoe, K., Murakami, K., and Yamada, Y. (2006). New dammarane-type saponin from roots of Panax notoginseng.. Nat. Med. 60,135-137. 

Kuwahara, M., Kawanishi, F., Komiya, T., and Oshio, H. (1989). Dammarane saponins of Gynostemma pentaphyllum Makino and isolation of malonylginsenosides-Rbl,- Rd, and malonylgypenoside V. Chem. Pharm. Bull. 37,135-139. 

Nakamura, S., Sugimoto, S., Matsuda, H., and Yoshikawa, M. (2007a). Structures of dammarane-type triterpene triglycosides from the flower buds of Panax ginseng. Heterocycles 71, 577-588. 

Tanaka, O., and Yahara, S. (1978). Dammarane saponins of leaves of Panax pseudo-ginseng subsp. himalaicus. Phytochemistry 17,1353-1358. 

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