Phytochemicals definition

Classification Phytochemical Definition Predominant flavonoid in iemons and sweet oranges Empirical C28H34O15... 

It is clear, however, that the extensive problems concerning phytochemical relationships which have been raised as the result of the work summarized in this review cannot be resolved in the present state of knowledge. So far, in spite of the considerable attention given by many workers in this difficult field, little more than a preliminary survey of the possibilities has been achieved. Further investigations, which will almost certainly require novel methods of approach, will be necessary in order to decide unequivocally the structural formulas of the components of pectic materials, and only when such further knowledge is available will it be feasible to reach definite conclusions regarding their phytochemical relationships. 

No new alkaloids have been discovered within this family. A phytochemical investigation of plants of the Boraginaceae indigenous to France has been carried out.11 Pyrrolizidine alkaloids were detected in 23 species from 14 genera, and N-oxides were present in 12 species. No definite identifications were made. 

Ultimately, the definitive structure elucidation of unknown molecules is most often accomplished via NMR. NMR has traditionally been performed on the purified natural product isolated using bioassay-guided fractionation. With the advent of hyphenated techniques such as LC/NMR, these data can now be obtained prior to purification [130,131]. LC/NMR can prove useful even in the dereplication phase, particularly when LC/UV/MS data are insufficient for unambiguous peak identification. LC/NMR has played an important role in natural products structure elucidation, where several related compounds (factors) are often encountered in a single sample. For example, isobaric or isomeric mixtures that may prove difficult or impossible to differentiate by MS, can often be readily distinguished by NMR. Several thorough reviews of LC/NMR in natural products discovery and phytochemical analysis have recently appeared [132,133]. 

Interest in enzyme stereospecificity and the stereochemistry of prochiral centres, such as the methylene groups of mevalonic acid, has necessitated more precise definitions of the stereochemistry of the various molecules involved and of the enzymological consequences. The use of multiply labelled mevalonic acid in terpenoid and steroid biosynthesis has been reviewed by Hanson. The Proceedings of the 1970 Phytochemical Society symposium have been published. They include a general discussion of terpenoid pathways of biosynthesis by Clayton and specific chapters on monoterpenoids, diterpenoids, eedysones, carotenoids, isoprenoid quinones, and chromanols. Other reviews concerning biosynthesis have appeared on furanocoumarins, indole alkaloids, monoterpenoids, and diterpenoids. ... 

Nutraceuticals are nonspecific biological therapies used to promote wellness, prevent malignant processes, and control symptoms. It is a broad umbrella term used to describe any product derived from food soiuces that provides extra health benefits in addition to the basic nutritional value foimd in foods. The definition of nutraceuticals and related products often depends on the soiuce. Phytochemicals and antioxidants are two specific types of nutraceuticals. It has been proved that phytochemicals found in foods may help to provide protection from diseases such as cancer, diabetes, heart disease, and hypertension, for example, carotenoids found in carrots. Antioxidants may be helpful in avoiding chronic diseases, by preventing oxidative damage in body [8]. There are multiple different types of products that come imder the category of nutraceuticals ... 

It is premature to draw any definitive conclusions about the systematic significance of alkylquinolin/ones in bacteria on the basis of the presently insufficient phytochemical data. The above comments are only speculations. 

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