Anthocyanins transport

Grapevine MATE-type proteins act as vacuolar H+-dependent acylated anthocyanin transporters. Plant Physiol 150 402-415. 

Goodman CD, Casati P, Walbot V. 2004. A multidrug resistance-associated protein involved in anthocyanin transport in Zea mays. Plant Cell 16 1812-1826. 

More studies should be carried out in what concerns anthocyanin transport across biological membranes. There are studies aimouncing neuroprotective effects of anthocyanin-rich foods, but there is a gap in the knowledge concerning, for example, anthocyanin (and metabolites) transport across blood-brain barrier. On top of this, it is urgent to know dietary factors able to modulate anthocyanin bioavailability, helping health professionals to make dietary recommendations. These recommendations will be relevant for a healthy life but also to alert medical doctors as to possible pharmacological interactions with anthocyanins. 

In spite of this genetic evidence, implying an evolutionary conserved role of sequence-divergent GSTs in anthocyanin transport (Alfenito et al., 1998 Larsen et al, 2003), the biochemical function of anthocyanin-related GSTs remains obscure, most importantly because neither Bz2 nor An9 catalyze the fonnation of an anthocy-anin-conjugate with GSH (Mueller et al, 2000). In contrast, tran -cinnamic acid and some derivatives had been shown to be capable of the... 

The semiconductor structure is crucial for both electron injection and charge transport after the exciton separation. Meng et al. [35] published a theoretical study focused on the electron injection mechanism in dyad anthocyanine-Ti02 nanowires. 

Secondary compounds produced by plants may have other significant survival roles, such as signals to attract insects, birds, or other animals to enhance pollination or seed dispersal. In addition to any potential functions, secondary compounds may concomitantly serve a physiologic function, such as protection against ultraviolet (UV) light or frost, or provide a function in nitrogen transport and storage. In several instances, compounds can serve multiple functions in the same plant. Anthocyanins or monoterpenes can be... 

There is also a preliminary report of a P. frutescens cDNA encoding a membrane protein of unknown function (8R6) that promotes anthocyanin uptake into protoplasts and anthocyanin accumulation when overexpressed in A. thaliana transgenics.Within the vacuole of some plants (but not A. thaliana) the anthocyanins may occur in protein containing bodies, termed anthocyanic vacuolar inclusions (AVIs), whose function is as yet unknown but may relate to transport activities. ... 

There are few studies on vacuolar importation of flavonoids other than anthocyanins and PAs. Klein et al. reported uptake of flavone glycosides by isolated H. vulgare primary leaf vacuoles via a vacuolar H -ATPase linked mechanism,and by vacuoles from Secale cereale (rye) mesophyll via a possible ABC transporter mechanism. Li et al. "" found medicarpin conjugated to glutathione was also sequestered by an ABC transporter mechanism. 

Mathews, H. et al.. Activation tagging in tomato identifies a transcriptional regulator of anthocyanin biosynthesis, modification, and transport. Plant Cell, 15, 1689, 2003. 

This biotransformation is common to many xenobiotics and diminishes the potential toxicity of the substrate and facilitates its biliary and urinary elimination by increasing its hydrophilicity. Flavonoid metabolites are transported to extrahe-patic tissues and eventually to the kidneys, where they are excreted in the urine or incorporated into bile and excreted in feces.13 Because phase II metabolism is highly efficient with respect to the flavonoids, aglycones (except for anthocyanins)... 

In some instances, additional functions are the attraction of pollinating or seed-dispersing animals, for example, by colored compounds such as betalains (within the Centrospermae), anthocyanins, carotenoids, and flavonoids or by fragrances such as terpenes, amines, and aldehydes 15,17). Physiological roles, such as UV protection [by fiavonoids or cou-marins 4,17)], nitrogen transport or storage 14,36,37), or photosynthesis (carotenoids), may be an additional function. 

S aij a A, Princi P, D Amico N, De Pasquale R, Costa G. Effect of Vaccinium myrtillus anthocyanins on triiodothyronine transport into brain in the rat. Pharmacol Rev 1990 22 59-60. 

Although no fiirther work has been published on transport of indole alkaloids across the tonoplast, much work has since been published about tonoplast transporters, which may add some relevant clues. It was shown that in maize, the last step in anthocyanin biosynthesis involves its conjugation to glutathione and this conjugate is then recognized for transport into vacuoles by the glutathione pump [158]. This pump is... 

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