Exudate resin

Benzoic acid had been known for several hundred years by the time of Mitscher lich s experiment Many trees exude resinous materials called balsams when cuts are made m their bark Some of these balsams are very fragrant which once made them highly prized articles of commerce especially when the trees that produced them could be found only m exotic faraway lands Gum benzoin is a balsam obtained from a tree that grows m Java and Sumatra Benzoin is a word derived from the Erench equivalent benjoin which in turn comes from the Arabic luban jawi meaning incense from Java Benzoic acid is itself odorless but can easily be isolated from gum benzoin... 

Natural resins are substances with a high viscosity, semisolids or solid and insoluble in water. They are formed in the so-called resiniferous canals of several trees. Many varieties of plants spontaneously exude resins as a product of their metabolism, to protect themselves against excessive loss of water and attack from micro-organisms. 

CBN) from the exuded resin of Indian hemp ( charas ), which analyzed for C2iH2602- Another, big step was made by Cahn, who advanced the elucidation of the structure of CBN (Cahn, 1932). Several years later, Todd s group and Adam s group elucidated the correct structure of CBN by synthesizing and comparing various possible structures. ... 

Figure 14, SEM resin ducts in spruce wood. (A) Vertical duct with exuded resin droplets. (Reproduced from Ref. 39. C( yright 1982, American Chemical Society.) (d) Horizontal ducts contained in fusiform rays (FR) of the wood tangential surface.

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. 

Many plants, when damaged, exude resinous materials as a defence mechanism. Rosin is produced as a physical barrier to infectious organisms, by pine trees when the bark is damaged. Similarly, rubber is... 

Many plants, particularly trees, exude resins when their bark is damaged. Deliberate damage and subsequent collection of the resin is known as tapping. This method is used to collect latex for rubber production and for gum turpentine. It is also used to produce frankincense (also known as olibanum), myrrh and other similar fragrance materials although in these cases there is usually further processing of the resin after collection. 

The terpenoids can be defined as a group of natural products whose structure may be divided into isoprene units (13). Isoprene, or isopentenyl, is a C5 (five carbon atom) compound, which can be viewed as the terpenoid building block (Figure 2). Both the lower terpenoids (monoterpenoids and sesquiterpenoids) and the higher terpenoids (diterpenoids and triterpenoids) are built up from multiples of these isoprene units. When freshly exuded, resins tend to be liquid or semi-liquid, as they contain either one or the other of the two higher terpenoids in solution in a mixture of the more volatile lower terpenoids. 

The most important natural sources of flavors are the essential oils derived from spices, fruits, and flowers as well as extractives and exudates (resins) from certain plant sources and animal secretions, e.g., musk. Essential oils are aromatic substances which are widely used in several industries such as perfume, pharmaceutical, food, and nutrition. These are mixtures of more than 200 compounds [14,16]. It contains monoterpenes, sesquiterpene hydrocarbons, and their oxygenated derivatives, along with aliphatic and aromatic aldehydes, alcohols, esters, and nonvolatile residues. Generally, terpenes are unsaturated com-... 

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