Higher plants woody

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. 

Fig. 5.4 Plots of lignin oxidation product parameters permitting distinction of different higher plant tissues (a = non-woody angiosperm, wa = woody angiosperm, g = non-woody gymnosperm, wg = woody gymnosperm, n = non-vascular plant tissue).Amounts of syringyl and vanillyl components in (a) are expressed as wt % of vascular plant organic carbon (after Hedges Mann 1979).

The crystalline phases la and ip can occur in variable proportions according to the souree of the cellulose. The eelluloses produeed by primitive organisms (baeteria, algae, and the like) are enriched in the la phase, whereas the cellulose of higher plants (for instance, woody tissues, cotton, and ramie) eonsists mainly of the ip phase. Study... 

Starch is one of the most abundant polysaccharides occurring in nature. All organs of higher plants contain starch. Starch granules can be found in pollen, leaves, stems, woody tissues, roots, tubers, fruits, flowers, bulbs, and seeds. Starch can also be found in mosses, ferns, algae, and bacteria. 

Coal may be regarded as a combustible sedimentary rock. Whereas the majority of rocks are mostly inorganically derived, coal consists predominantly of organic matter, largely derived from a variety of plant remains (higher plants, ferns, fungi, algae) and different tissues (leaves, stalks, woody trunks, bark, pollen, spores, sclerotia, resins, etc.) with associated mineral constituents. 

Lignin is one of the principal costituents of the woody structure of higher plants, typically 30% of a plant s dry weight, (7) and structurally is a highly intricate aromatic polymer of phenylpropenoidic compounds (2-6). Oxidative processes are involved both in the polymerization of phenylpropenoidic phenols to lignin and in the degradation of lignin in the enviroment (7-8). The use of model systems for the... 

The flavonols reported in woody tissues are listed in Table 7.5.2. Some typical structures are 16 through 23. The most common flavonol of higher plants is quercetin and this substance is reported as a very frequent constituent of gymno-sperm woods and barks. In the angiosperm woods, the flavonols most frequently... 

H-)-a-Longipinene (347) arising from cation 337 was first found in wood of Pinus sylvestris (414). Many related compounds have since been isolated from woody tissues of higher plants (47) - for example, rastevione (348) from roots of Stevia serrata and S. rhombifolia (329). Longiborneol (juniperol, 349) is widely distributed in the Pinus spp. but was first obtained from bark of Juniperus... 

Carotenoids are essential components of all photosynthetic tissues. They have also been isolated from non-photosynthetic organs of higher plants, such as flowers, fruits, and seeds. However, they do not seem to occur in woody tissues, and hence will not be discussed any further. 

Polyprenols of higher plants have mostly been isolated from leaves solanesol (C45) was first obtained in 1956 from tobacco leaves. However, their occurrence in certain woody tissues has been demonstrated. Silver birch (Betula verrucosa) wood has been shown to contain fatty acid esters of betulaprenols -6 to -9 the major polyprenol, betulaprenol-7 has the structure cu-T-T-C-[C]2-C-OH (573) the poli renols from the leaves were free, and the major component had 11 isoprene units (188, 256). 

This review is intended to identify drugs currently in use that are found in woody parts of higher plants and to survey the current literature for additional pharmacologically active secondary metabolites extracted from wood that have interesting and/or potential future application as drugs for humans. The reader is directed to an interesting publication surveying potential useful secondary metabolites from Eastern hardwoods (884). 

There are currently about 25 drugs that occur appreciably in the woody parts of higher plants. Most of these are alkaloids. 

The higher plant cellulosic fiber is sub-divided into non-woody fibers (straw, grass, bast, trunk, stem, frond, leaf, seed and fruit) and woody fibers (pine, rubber. Acacia, teak) (Nazir, 2013). Different plant biomass possesses different composition of cellulose (g/g) such as jute (61-71.5%), flax (71%), hemp (60.2-74.4%), ramie (68.6-76.2%), kenaf (31-39%), sisal (67-78%), pineapple leaf fiber (70-82%), henequen (77.6%), cotton seed (82.7%), rice... 

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