Dipterocarpaceae genera

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. 

A number of important resins are composed of triterpenoids, including the dammar resins which derive from a sub-family of the family Dipterocarpaceae. Dammar resins are fluid, balsamic oleoresins highly suited for caulking and waterproofing. Frankincense (olibanum) is known as a gum-resin collected from various Boswellia spp. and contains amyrin epimers and triterpenoid acids. The gum component is polysaccharide in origin and is water soluble. The Anacardiaceae family contains the genus Pistacia (Mills and White, 1977 21 Mills and White, 1989). 

The Dipterocarpaceae constitute a tropical family found especially in Malaysia. It yields timber, resins, and an edible fat from one genus (Shored). 

Monotoideae (two genera and more than 30 species) occurs in mainland Africa and Madagascar [3,7,8], and the subfamily Pakaraimoideae (one genus and one species) is indigenous to northern South America [6]. All members of the Dipterocarpaceae grow in tropical climates, and survive approximately 1000 mm of annual rainfall and a dry season of less than six months per year [1]. Most species in this family are found below 1000 m, but a few are confined only to altitudes above 700 m [1]. 

The value of sesquiterpenoids as chemotaxonomic markers has received some attention (140, 155). Much discussion has been focused on their importance in Compositae phylogeny, at the genus and species level (153, 191, 193). Sesquiterpene distribution in the family Dipterocarpaceae has been studied (37). 

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