Phenolics are broadly distributed in the plant kingdom and are the most abundant secondary metabolites of plants. Plant polyphenols have drawn increasing attention due to their potent antioxidant properties and their marked effects in the prevention of various oxidative stress associated diseases such as cancer. In the last few years, the identification and development of phenolic compounds or extracts from different plants has become a major area of health- and medical-related research. This review provides an updated and comprehensive overview on phenolic extraction, purification, analysis and quantification as well as their antioxidant properties. Furthermore, the anticancer effects of phenolics in-vitro and in-vivo animal models are viewed, including recent human intervention studies. Finally, possible mechanisms of action involving antioxidant and pro-oxidant activity as well as interference with cellular functions are discussed.

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Plant phenolics: extraction, analysis and their antioxidant and anticancer properties.

In his recent review of the developing theory of insect-plant interactions, Gilbert (52) identified four major thrusts in research: insect-plant coevolution, host plants as islands, plant apparency and chemical defense, and resource predictability versus evolutionary strategies of insects. From his review it is evident that, with a few exceptions (23, 45, 53, 64), developing theory is addressing primarily a two trophic level system. In reality, of course, all terrestrial communities based on living plants are composed of at least three interacting trophic levels: plants, herbivores, and natural enemies of herbivores. We argue that theory on insect-plant interactions cannot progress realistically without consideration of the third trophic level. A closer look at the mechanisms of interactions reveals a paradox, and plants have many effects, direct and indirect, positive and negative, not only on herbivores but also on the enemies of herbivores. The third trophic level must be considered as part of a plant's battery of defenses against herbivores.

http://max2.ese.u-psud.fr/epc/conservation/PDFs/HIPE/Price1980.pdf

Interactions Among Three Trophic Levels: Influence of Plants on Interactions Between Insect Herbivores and Natural Enemies

Extraction and analysis of phenolics in food

Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. The elucidation of the biosynthetic pathways, as well as their regulation by MYB, basic helix-loop-helix (bHLH), and WD40-type transcription factors, has allowed metabolic engineering of plants through the manipulation of the different final products with valuable applications. The present review describes the regulation of flavonoid biosynthesis, as well as the biological functions of flavonoids in plants, such as in defense against UV-B radiation and pathogen infection, nodulation, and pollen fertility. In addition, we discuss different strategies and achievements through the genetic engineering of flavonoid biosynthesis with implication in the industry and the combinatorial biosynthesis in microorganisms by the reconstruction of the pathway to obtain high amounts of specific compounds.

/pdf/flavonoids-biosynthesis-biological-functions-and-140f6kuymp.pdf

Flavonoids: biosynthesis, biological functions, and biotechnological applications.

Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.

Phenolics in food and nutraceuticals

https://zenodo.org/record/1259683/files/article.pdf

The conversion of procyanidins and prodelphinidins to cyanidin and delphinidin

Maysin (rhamnosyl-6-C-(4-ketofucosyl)-5,7,3′, 4′ tetrahydroxyflavone (I), isolated from corn silks of the exotic strain Zapalote Chico’ has been shown to severely retard the growth of Heliothis zea (Boddie) when incorporated into the insect's diet. Data indicate that the presence of this flavone glycoside may be related to the natural resistance of corn against corn earworm.

Maysin, a Flavone Glycoside from Corn Silks with Antibiotic Activity Toward Corn Earworm

Several compounds that retard the larval growth of the tomato fruitworm,Heliothis zea (Boddie) have been isolated and identified from tomato leaves,Lycopersicon esculentum Mill. The major allelochemics are α-tomatine (I), chlorogenic acid (II), rutin (III), and a new caffeyl derivative of an aldaric acid (IV). The isolation, analyses, and toxicity of these compounds toH. zea are presented.

Bock G. Chan

Papers

The conversion of procyanidins and prodelphinidins to cyanidin and delphinidin

Maysin, a Flavone Glycoside from Corn Silks with Antibiotic Activity Toward Corn Earworm

Growth inhibitors in tomato (Lycopersicon) to tomato fruitworm (Heliothis zea).

Condensed tannin, an antibiotic chemical from Gossypium hirsutum

Effects of cotton condensed tannin on feeding and digestion in the cotton pest, Heliothis zea