Flavonoids distribution

Before a species is analyzed with respect to its flavonoid content, knowledge about earlier reports on the chemistry and flavonoid distribution within the genus and related species may be of value. The most exhaustive source for such information is Chemical Abstracts, and excellent reviews on structures and distribution of flavanoids have been compiled regularly.Several reviews have recently addressed the general field of flavonoid analysis.Among the earlier reviews in the field, we will particularly recommend consulting Techniques of Flavonoid Identification by Markham and Plant Phenolics by Harborne. References to review articles on specific spectroscopic techniques applied on flavonoids will be cited under the various spectroscopic methods covered in this chapter. Spectroscopic information of importance is also presented in several other chapters in this book. 

Charriere-Ladreix, Y. and Tissut, M., Foliar flavonoid distribution during Spinacia chloroplast isolation, Planta, 151, 309, 1981. 

Flavonoids can bind to plasma albumin,41 possibly decreasing their diffusion into cells.42 A 10% reduction of plasma albumin in older individuals43 44 could impact flavonoid distribution to tissues however, in fact, age-related decreases of albumin binding appear to have a minimal impact on the Vd of drugs 45... 

Anthocyanins are a proanthocyanidin-type of flavonoid distributed in various fruits. These anthocyanins are the most important visible plant pigments in the natural kingdom. Anthocyanins have been clinically used in many folklore medicines worldwide for the treatment of age-related diseases and other disease. This review presents the functionality of anthocyanins in relation to their chemistry, synthetic pathway, antioxidant activity, antitumor activity (including apoptosis-inducing activity), pharmacodynamics (absorption, metabolism, distribution, and excretion) and toxicity, and discusses their possible use as food and dietary supplements and usage in potential nutraceuticals. 

Barreca, D., Bellocco, E., Caristi, C., Leuzzi, U. and Gattuso, G., 2011. Kumquat Fortunella japonica Swingle) juice Flavonoid distribution and antioxidant properties. Food Research International 44(7), 2190-2197. 

We are concerned here with systems that have been studied using secondary products—flavonoids and terpenoids in particular— but other information, including micro- and macrofossils, and occasionally chromosome numbers, will be included in the discussions when snch information is available. The majority of current research on postglacial reestablishment of plant distribution patterns is based on DNA seqnence information. In a few instances below, reference will be made to such information, but this in not the place for a detailed review of that literature. 

Table 4.3 Distribution of flavonoids in Restionaceae in Australia and Africa (from Williams etal., 1998)...

A detailed study of the flavonoid chemistry of the island endemics, the closely related G. tinctoria, and live additional species from the mainland provided additional evidence pointing toward G. tinctoria as the ancestral species (Pacheco et al., 1993). The flavonoid profiles of all species consisted of flavonol glycosides as major components with an unidentified flavone glycoside and several unidentified phenolic compounds (presumably not flavonoids). The pattern of distribution of the flavonol glycosides and unidentified flavones within the set of nine species proved to be extremely informative. (The phenols were ubiquitous and are not considered further.) Kaempferol glycosides were seen in neither the island species nor G. tinctoria, but were present, in several combinations, in the rest of the mainland taxa. The isorhamnetin glycosides showed the reverse pattern, with one exception the island endemics and G. tinctoria exhibited these compounds, whereas four of the other mainland species did not. The sole exception is G. boliviari, which exhibited one of the isorhamnetin derivatives. 

Chrysosplenium enjoys a distribution that qualifies it for inclusion in several categories in this review. Members are known from northern Enrope, North America, eastern Asia (principally Japan), and extreme southern Sonth America. The similar flavonoid chemistry of the eastern North American-western North American species pair C. americanum and C. glechomaefolium was mentioned earlier, along with comments on apparent flavonoid differences between sections Alternifolia and Oppositifolia. 

Valant-Vetschera, K. M. and Wollenweber, E. 1988. Leaf flavonoids of the Achillea millefolium group. 11. Distribution patterns of free aglycones in leaf exudates. Biochem. Syst. Ecol. 16 605-614. 

There has been some evidence of a higher antioxidant effect when both flavonoids and a-tocopherol are present in systems like LDL, low-density lipoproteins (Jia et al., 1998 Zhu et al, 1999). LDL will incorporate a-tocopherol, while flavonoids will be present on the outside in the aqueous surroundings. A similar distribution is to be expected for oil-in-water emulsion type foods. In the aqueous environment, the rate of the inhibition reaction for the flavonoid is low due to hydrogen bonding and the flavonoid will not behave as a chain-breaking antioxidant. Likewise, in beer, none of the polyphenols present in barley showed any protective effect on radical processes involved in beer staling, which is an oxidative process (Andersen et al, 2000). The polyphenols have, however, been found to act synergistically... 

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