Resins gymnospermous

Woody higher plants can also exude resins. For example, dammar resin from certain angiosperms (e.g. dipterocarps) contains a polycadinene (Fig. 2.26), based on a A5-cadinene monomer (van Aarssen et al. 1990). Gymnosperm resin polymers are based on labdatriene (diterpenoid) monomers such as communic acid (Fig. 2.26 Mills et al. 1984/5 Hatcher Clifford 1997), and some angiosperm resins also contain these polymers. In contrast to polycadinene formation, polymerization of labdatrienes is thought to occur after exudation. 

Cyclic diterpanes with two (labdane), three (abietane, isopimarane and rimuane) or four rings (e i-beyerane, e i-kaurane and phyllocladane) can be particularly abundant where there has been a significant contribution from gymnospermous resins, such as in coals (Fig. 5.28 Aplin et al. 1963 Noble et al. 1985, 1986 Weston et al. 1989 Otto Simoneit 2001). 

Diterpenoids Gymnosperm resins, waxes Natural/thermally altered... 

A large series of diterpenes possess a 5a,10p-configuration. These are commonly accumulated in gymnosperms and in members of the Fabaceae subfamily Caesalpinioideae. These diterpenes have been isolated as by-products of turpentine manufacture and by collection of the resin from plants of this group. Crude mixtures of many of these compounds have been called naval stores. ... 

Pinaceae, usually are diterpenes with a 5a,10p-configura-tion. Many plants serve as commerical sources of resins the genera Hymenaea and Copaifera (Fabaceae) and Pinus and Agatha (gymnosperms) are probably the best known producers. Resins are used as feedstocks for products such as insecticides, incense, varnishes, rosin, and adhesives, and as components of drugs and polishes. Fossilized deposits of diterpenes are known as amber (Langenheim, 1990). 

Representatives of 55 families of vascular plants have been found to contain L.Gymnosperms feature prominently as L.-containing plants. L. occur in all parts of the plant, wood and resin being especially rich sources. L. have been isolated which possess antitumor, antimitotic, antiviral, insecticidal, piscicidal, antibacterial and fungistatic properties. Some L. inhibit mammalian cyclic AMP phosphodiesterase, and... 

D-Pinitol (lD-3-O-methyl-cA/ro-inositol) is the most widely distributed inositol ether. It has been found in six gymnosperm families and 13 angiosperm families (137). In gymnosperms, it is a component of the resin of Pinus lamber-tiana (see 137) the bark of Picea abies, Pinus nigra (71), Pinus halepensis, and Schinus molle (72) (where its content has been determined as a function of season) the cambial sap of Pinus silvestris, Picea abies, and Abies alba (114) and the wood of Pinus spp. (see 6, 137) and Sequoia sempervirens (153). It also occurs in various plant parts, including latex and wood Acacia mollissima), of angio-sperms (see 137). 

Woody biomass, either gymnosperms (softwoods) or angiosperms (hardwoods) is inherently anisotropic and hygroscopic it is porous material, with the porosity caused by the hollow fibers that make up the woody material. Any number of wood technology texts (see, for example, Haygreen and Bowyer [13]) describe the physical structure of woody biomass. The porosity or void volume of wood exists as macropores—tracheids, rays, resin canals and related structures useful in moving moisture and nutrients within the tree. Chemically, woody biomass is comprised of cellulose, the hemicelluloses, one or another type of lignin, and extractives such as pinoresinol, catechin, pinosylvin, and related compounds. 

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