Extractives biosynthesis

Bacterial polymers obtained by any form (e.g. extraction, biosynthesis methods, tailor-made synthesis) are used for various industrial, agricultural, and biomedical applications [120]. The details of the applications are listed in Table 11.1. 

Kumar, R., Roopan, S.M., Prabhakam, A., Khanna, V.G., Chakroborty, S., 2012. Agricultural waste Annona squamosa peel extract biosynthesis of silver nanoparticles. Spectrochim. Acta A 90, 173—176. 

Another technique that will be of increasing help in our understanding of extractives biosynthesis are detailed studies of the location of various enzymes within the tree. A recent example of such work is that of Stich and Ebermann (55) who showed that isoenzymes of peroxidase and polyphenol oxidase were identical in the sapwood and heartwood of oak. This work shows that there is a potential for polymerization of monomers to lignin in unlignified parenchyma cells at the sapwood/heartwood boundary as well as in the zone of active lignification close to the cambium. It could also help to explain the formation of the heartwood lignin-like polymers mentioned in Section 11.6.5. 

The earliest references to cinnamic acid, cinnamaldehyde, and cinnamyl alcohol are associated with thek isolation and identification as odor-producing constituents in a variety of botanical extracts. It is now generally accepted that the aromatic amino acid L-phenylalanine [63-91-2] a primary end product of the Shikimic Acid Pathway, is the precursor for the biosynthesis of these phenylpropanoids in higher plants (1,2). 

The significance of these metabolites in the biosynthesis of the thiamine thiazole in considered next. Although, from their constitution, and from the tracer experiments, the metabolites are undoubtedly the products of transformation of 1-deoxy-D-t/ireo-pentulose, their significance in the biosynthesis of the thiazole of thiamine is not clear. The thiazole glycol is not a product arising from a transformation of the thiazole (5) of thiamine. Reduction to this thiazole (5) occurs in dialyzed extracts of disrupted cells, in the presence of ATP, NADH, and NADPH, but only at 0.2% the rate of synthesis of the thiamine thiazole (5) by intact cells. The behavior of the thiazole glycol on plates is merely a consequence of the extreme sensitivity of the tetrazolium reagent. 

Suzuki, T. and Takahashi, E., Biosynthesis of caffeine by tea-leaf extracts, Biochemistry, 146,87,1975. 

As the result of a screening program examining microbial fermentation products for pharmacological activity (other than antibiotic activity), fusaric acid (10) was isolated from Fusarium oxysporum following the discovery that extracts were potent inhibitors of dopamine p-hydroxylase, and thus interfered with the biosynthesis in vivo of the pressor neurohormone, norepinephrine. To refine this lead, amidation of 10 via the acid chloride was carried out... 

Natural thickeners are derived from plants by extraction from part of the plant itself or from a plant secretion their biosynthesis is now a possibility. These products are generally polysaccharides and are thus closely related to cellulose. They consist of homo- or... 

Ankamwar, B., Damle, C., Ahmad, A. and Sastry, M. (2005) Biosynthesis of gold and silver nanoparticles using Emhlica Officinalis fruit extract, their phase transfer and transmetallation in an organic solution. Journal for Nanoscience and Nanotechnology, 5, 1665-1671. 

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