Special Issue "Phenolics and Polyphenolics"

Guest Editor
Prof. Dr. Liselotte Krenn
Institute of Pharmacognosy, PharmaCenter Vienna, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria
E-mail:

Editorial Advisor
Prof. Dr. Paula Andrade
REQUIMTE/Serviço de Farmacognosia, Faculdade de Farmácia, Universidade do Porto, R. Aníbal Cunha, 164, 4050-047 Porto
E-mail:

Editorial Advisor
Prof. Dr. José Alberto Pereira
CIMO/Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Sta Apolónia, Apartado 1 172, 5301-855 Bragança, Portugal
E-mail:

Dear Colleagues,

This special issue of the International Journal of Molecular Science is dedicated to phenolics and polyphenols. Polyphenols are among the most abundant substances produced in plant kingdom comprising numerous diverse classes of secondary metabolites such as phenolic acids, flavonoids, tannins, coumarins, stilbenes, lignans.

During the recent decades such compounds have gained an enormous interest in research. Their diverse functions in plants, biosynthesis, biological properties etc. are studied in detail. Besides that the health effects of phenolics and polyphenols are investigated intensively. Numerous representatives of these compounds are e.g. assumed to contribute by different modes of action to the prevention of chronic diseases associated with oxidative stress such as cancer or cardiovascular diseases. This has stimulated investigations not only on the activites but also on the concentrations of such compounds in all kinds of food and medicinal plants as well as on their intake, absorption, bioavailability and metabolism. Recommendations to ingest of high amounts for preventional purposes have raised the question of toxicity and led to respective studies.

For the use of extracts rich in polyphenols in herbal medicinal products and food supplements, the development of appropriate analytical methods and optimum formulations are important research fields as well.

Nevertheless, there are still apparent gaps in the knowledge concerning phenolics and polyphenols. Besides many others e.g. the full understanding of their role and function in plants at the molecular level or interactions in the environment need further investigation. Thus, this special issue shall help to fill some of the gaps in all above mentioned fields of research.

Liselotte Krenn
Guest Editor

Submission

All papers should be submitted to ijms@mdpi.org. To be published continuously until the deadline and papers will be listed together at the special issue website.

Submitted papers should not have been published previously, nor be under consideration for publication elsewhere. All papers are refereed through a peer-review process. A guide for authors is available on the Instructions for Authors page. The International Journal of Molecular Sciences is an international peer-reviewed monthly journal published by Molecular Diversity Preservation International.

Open Access publication fees are 800 CHF per paper. English correction fees and/or formatting fees (250 CHF) will be added in certain cases (1050 CHF per paper for those papers that require extensive additional formatting and/or English corrections).

Also see a list of papers published on the same topic in Molecules in 2007.

• phenolics
• polyphenolics and molecular sciences

Feature Papers

Type of Paper: Review
Title: Methylation of Dietary Flavones Increases Their Metabolic Stability and Chemopreventive Effects
Authors: Thomas Walle
Affiliations: Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA; Tel. +1 843 795-3492; E-mail: wallet@musc.edu
Abstract: Dietary flavones have been shown to have promising chemopreventive properties, in particular with regard to cancer. However, problems with too low oral bioavailability and sometimes unacceptable toxicity have made them questionable for use as protective additives to normal diets. Research in pharmacognosy has revealed many flavone derivatives, some of which may have superior chemopreventive properties, e.g. methylated flavones, or methoxyflavones. First, recent studies have shown that methylation of free phenolic hydroxyl groups leads to derivatives lacking the propensity for undergoing conjugation to either glucuronic acid or sulfate conjugates, resulting in much increased metabolic stability. Such methylation also leads to greatly improved transport through biological membranes, such as in intestinal absorption. Second, recent studies also indicate that methylation results in derivatives with increasing potency to kill cancer cells, although these effects may be cell-specific. They also show high potency towards inhibition of hormone-regulating enzymes, e.g., aromatase, responsible for production of estrogen hormones, critically important in the causation of breast cancer. Third, preliminary studies suggest that methylation of the flavones results in more soluble derivatives, of great importance for pharmaceutical preparations. Importantly, although the data are limited, they also suggest that methylation of flavones results in derivatives with much diminished ability to produce unwanted side-effects. In conclusion, it appears that methylation of dietary flavones as well as other food products may produce derivatives with much improved health effects.

Type of Paper: Review
Title: Recent Progress of Flower Color Modification by Biotechnology
Authors: Yoshikazu Tanaka 1,* and Stephan Chandler 2
Affiliations: 1 Institute for Plant Science, Suntory Ltd., 1-1-1 Wakayamadai, Shimamoto, Mishima, Osaka 618-8503, Japan 2 Florigene Pty Ltd., 1 Park Drive, Bundoora, Victoria - 3083, Australia
* Author to whom correspondence should be addressed; Tel. +81 75-962-8807; Fax: +81 75-962-3791; E-mail: Yoshikazu_Tanaka@suntory.co.jp
Abstract: Genetically-modified, colour-altered varieties of the important cut-flower crop carnation have now been commercially available for nearly ten years. In this review we describe the manipulation of the anthocyanin biosynthesis pathway that has lead to the development of these varieties and how similar manipulations have been successfully applied to both pot plants and another cut-flower species, rose. From this experience it is clear that both down- and up-regulation of the flavonoid and anthocyanin pathway is both possible and predictable. The major commercial benefit of the application of this technology has so far been the development of novel flower colours through the development of transgenic varieties that produce, uniquely for the target species, delphinidin-based anthocyanins. These anthocyanins are ubiquitous in nature, and occur in both ornamental plants and common food plants. Through the extensive regulatory approval processes that must occur for the commercialization of genetically modified organisms, we have accumulated considerable experimental and trial data to show the accumulation of delphinidin-based anthocyanins in the transgenic plants poses no environmental or health risk.

Type of Paper: Review
Title: Structural Features and Biological Properties of Ellagitannins in Some Plant Families of the Order Myrtales
Authors: Takashi Yoshida et al.
Affiliations: College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime, 790-8578, Japan; Tel. +81 89 926 7128; Fax: +81 89 926 7565; E-mail: tyoshida@cc.matsuyama-u.ac.jp
Abstract: Vegetable tannins, one of major groups of antioxidant polyphenols in medicinal plants, food and beverages have attracted a lot of attention in recent years because of their multifunctional properties beneficial to human health. The tannins with diverse structures are divided into two large groups, hydrolysable and condensed tannins. Among more than 500 hydrolysable tannins so far characterized, ellagitannins constitute the largest group which includesC-glucosidic ellagitannins and their condensates with flavan 3-ol (complex tannin), and oligomers which are biogenetically producible through intermolecular C-O or C-C coupling between monomers. These tannins distribute in dicotyledoneous plants of angiosperm. This review describes an outline and chemotaxonomical significance of structural features for various types of ellagitannins, focusing on the representative examples found in the polyphenol-rich plants belonging to Myrtaceae (Eucalyptus, Melaleuca, Eugenia, Psidium, and Syzygium genera), Lythraceae (Woodfordia, Lythrum and Lagerstroemia genera), Onagraceae (Oenothera species) and Melastomataceae of the order Myrtales. Biological activities of ellagitannins, which are related with antitumor and antibacterial effects, are also reviewed.

Type of Paper: Review
Title: Managing Phenol Contents in Crops by Phytochemical Farming and Breeding - Visions and Constraints
Authors: Dieter Treutter
Affiliations: Unit Fruit Science, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Dürnast 2, D-85354 Freising, Germany; Tel. +49 8161 71 3753; Fax: +49 8161 71 5385; E-mail: dieter.treutter@wzw.tum.de
Abstract: Phenolic compounds occur widely in plants and are a biological important and chemical diverse group of secondary metabolites. By contrast to earlier assessments, these compounds are no longer judged as waste products or as evolutionary remnants without current functions, nor as mere metabolic end products that are toxic to the plant and are therefore stored away in vacuoles. The beneficial effects of phenolics in protecting plants from pests and pathogens or for human health, provokes the idea of actively stimulating their biosynthesis and accumulation.
Agricultural Practices and Breeding
It is suggested that pathogens induce the biosynthesis of resistance related metabolites but non-pathogenic strains are also capable of eliciting secondary metabolites. Furthermore, the phenylpropanoid and flavonoid synthesis varies and is induced by factors such as UV-light, hydric stress, temperature or ozone. Agricultural practices have been evaluated in this context. Enhancing the colour of flowers of ornamental plants and of fruits such as apples is obviously a subject of plant breeders. The aim of creating a cultivar with a particular phenolic fingerprint is not easily attained since there are many enzymes and therefore many genes involved. Recently, test crossing made with buckwheat species revealed that breeding for increased flavonoid content may be successful. Alongside conventional breeding, genetic engineering may be a valuable tool for introducing new phenolics.
Constraints
Biosynthesis and accumulation of phenolic compounds are mostly restricted to specialized cells and tissues and moreover at a subcellular level. The secondary metabolism is integrated into programmes of growth and differentiation which means that relevant enzymes are not always present and active. This is known for instance for fruits, such as apples, pears, and strawberries. This complex integration is responsible for the fact that the responses of plant tissues to eliciting agents are highly variable and sometimes weaker than expected. The directed induction of both phenol biosynthesis and accumulation may be limited by ontogenetic constraints and, by limited substrate availability, this means carbon supply and energy which growth and secondary metabolism are competing for. The outcome of all those treatments which are targeted on the biosynthesis and accumulation of particular phenolics can only be predicted if the metabolism is fully understood. An attempt to introduce red pigmentation in forsythia flowers by introducing genes encoding for dihydroflavonol-reductase and anthocyanidin-synthase resulted only in a rather weak anthocyanin accumulation. At that time, the existence of an anthocyanidin-reductase converting anthocyanidins to epicatechin was still unknown. Even despite of exact knowledge of pathways, the quantitative availability of metabolic precursors may result in unpredicted events. When the goal of increasing the content of specific phenolic compounds in the target tissues is reached, possible feedbacks need to be considered since phenolics are potentially physiologically active. Interaction with plant hormones may explain the observed growth promotion of callus cultures by chlorogenic acid on auxin-free media. It is obvious that flavonoids may regulate auxin transport in plants. Inhibition of growth and xylogenesis and promotion of vacuolation in Prunus callus by the flavanone prunin was observed. Phenolics can alter membrane properties thus increasing leaching and tissue browning. Some phenolics are described as leaf-movement factors.
Conclusions
There are many instruments available to increase the content of phenolic compounds in plants. If there is success in reaching the goal enhancing the agronomic value of a given plant and increasing its stress resistance, this mainly depends on the integration of biosynthesis into growth and differentiation programmes. Therefore, breeding or genetic engineering may set the basis but success requires exact knowledge of the mechanisms of biosynthesis. The response of tissues to elicitation and induction of biosynthesis depends on the actual stage of growing and differentiation which can be influenced by various agricultural practices. A once induced accumulation of physiologically active phenolics may influence growth and differentiation processes as a feed back.

Type of Paper: Review
Title: Hypericins as Potential Leads for New Therapeutics
Authors: Anastasia Karioti, Maria Camilla Bergonzi and Anna Rita Bilia *
Affiliations: Department of Pharmaceutical Sciences; Via Ugo Schiff 6; I - 50019 Sesto Fiorentino (FI); Italy
* Author to whom correspondence should be addressed; Tel.
+39/055/4573708; Fax: +39/055/4573679; E-mail: ar.bilia@unifi.it
Abstract: One of the most promising group of polyphenols is represented by the naphthodianthrones hypericin and pseudohypericin, known for their antitumor, antiviral and antidepressant properties. Notably, hypericin is one of the most potent naturally occurring photodynamic agents; it is able to generate the superoxide anion and a high quantum yield of singlet oxygen that are considered to be primarily responsible for its biological effects. The produced ROS stimulate lipid peroxidation and protein cross-linkages associated to the formation of carbonyl products. The prooxidant photodynamic properties of hypericin have been exploited for the photodynamic therapy of cancer (PDT), as hypericin, in combination with light, very effectively induces apoptosis of cancer cells. In addition, hypericin inhibits several enzymes such as monoaminooxidase, protein kinase C, cytochrome P-450, telomerase and reverse transcriptase, most of these inhibitions requiring light and oxygen.

Type of Paper: Review
Title: Chemistry of Secondary Polyphenols Produced during Food Processing
Authors: Takashi Tanaka
Affiliations: Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan; Tel. +81-95-819-2433; Fax: +81-95-819-2477; E-mail: t-tanaka@nagasaki-u.ac.jp
Abstract: This review will introduce recent progress in the chemistry of secondary polyphenols produced during food processing. Production mechanism of the secondary polyphenols in black tea, whisky, cinnamon, and persimmon fruits will be mainly introduced. In the process of black tea production, tea leaf catechins are enzymatically oxidized to yield a complex mixture of oxidation products including theaflavins and thearubigins. Despite importance of the beverage, most of the chemical constituents have not been clarified yet due to the complexity. However, the reaction mechanisms at the initial stage of the catechin oxidation are explained by simple quinone–phenol coupling reactions. In vitro model experiments indicated occurrence of interesting regio- and stereoselective reactions. Recent results on the reaction mechanisms will be introduced. During the aging of whisky in oak wood barrels, ellagitannins originated from oak wood are oxidized and reacted with ethanol to give characteristic secondary ellagitannins. As for cinnamon, the major part of the cinnamon procyanidins is polymerized by copolymerization with cinnamaldehyde. In addition, anthocyanidin structural units were generated in the polymer molecules by oxidation and it account for the reddish coloration of cinnamon extract. The reaction is related to insolubilization of proanthocyanidins in persimmon fruits by condensation with acetaldehyde. In addition to oxidation, reaction of polyphenols with aldehydes may be important in food processing.

Type of Paper:Review
Title: The Creation and Physiological Relevance of Divergent Hydroxylation Patterns in the Flavonoid Pathway
Authors: Heidi Halbwirth
Affiliation: Inst. f. Verfahrenstechnik, Umwelttechnik und Techn. Biowissenschaften, Faculty of Technical Chemistry, Technical University of Vienna, Getreidemarkt 9, A-1060 Vienna; Austria
Tel. +43-1-58801x16601; Fax: +43-1-58801-16699; E-mail: hhalb@mail.zserv.tuwien.ac.at
Abstract: Flavonoids and the biochemically related chalcones are important secondary metabolites, which are ubiquitously present in plants and therefore also in human food. They fulfill a broad range of physiological functions in planta such as pollinator and bird attraction, UV and light protection, metal chelation, herbivore deterrence and pathogen defense. In addition, there are numerous reports on their physiological relevance for humans. Flavonoids have a basic C6-C3-C6 skeleton structure in common consisting of two aromatic rings (A and B) and a heterocyclic ring (C) containing one oxygen atom, whereas the chalcones, as the intermediates in the formation of flavonoids, have not yet established the heterocyclic C-ring. According to the oxidative status of the C-ring, flavonoids are classified into 8 different groups: flavans, flavanols, flavan diols, flavanones, flavones, dihydroflavonols, flavonols and anthocyanidins. More than 8000 different flavonoids and chalcones are known. The large number of divergent chalcones and flavonoid structures is due to extensive modification of the basic molecules. Introduction of additional hydroxyl groups frequently occurs and the hydroxylation pattern has an impact on physiological properties like flower color, antioxidative capacity and pest control. The most common flavonoids show a basic 5,7-hydroxylation pattern in the A-ring and one hydroxyl group in position 4’ of ring B. Furthermore, most flavonoid classes possess hydroxyl groups in ring C. The elucidation of the hydroxylation reactions is of particular interest. This review will summarize the knowledge on (i) the structural relationship between physiological function and the hydroxylation pattern and (ii) the enzymes and genes involved in the introduction of hydroxyl groups in the flavonoid structure.

Type of Paper: Review
Title: Bioactivity of Isoflavones: A Controversial Issue… or Maybe Not
Authors: M. G. Campos * and M. P. Matos
Affiliations: Centre of Pharmaceutical Studies - Laboratory of Pharmacognosy & Phytoterapy - Faculty of Pharmacy - University of Coimbra, Pólo III Ciências da Saúde, Azinhaga de Santa Comba 3000-548 Coimbra, Portugal; * Author to whom correspondence should be addressed; E-mail: mgcampos@ff.uc.pt
Abstract: The increase of life span will have profound implications in health in decades to come. By 2030 there will be 1.2 billion women in postmenopause. Hormone Replacement Therapy with synthetic hormones is still full of risks and according to the latest developments is to be used for as short a time possible. Searching for alternative drugs is inevitable in this scenario and science must provide physicians with other substances that can be used to treat the same symptoms with less side-effects.
Systematic research carried out on this issue now involves isoflavones but the randomised controlled trials and reviews of randomised trials concerning postmenopause therapy that could have an important impact on human health are very controversial.
The theoretical calculation that we propose in this paper integrates different knowledge about this subject and sets methodological boundaries that can be used to analyse data already published. The outcome should set some consensus for new clinical trials using isoflavones (isolated or included in mixtures) that will be evaluated for its therapeutical activity.
Probably this theoretical method for evaluation of a possible efficacy could be applied to other herbal drug extracts when a synergistic or contradictory bioeffect is not verified. In this way we may contribute to the understanding and the development of new therapeutic approaches.

Regular Papers

Type of Paper: Article
Title: Diurnal Variation in the Phenolic Content of Lettuce in Response to UV Irradiation
Authors: Athanasios Koukounaras ¹, Anastasios S. Siomos ^1,*, Dimitrios Gerasopoulos ² and Katerina Karamanoli ³
Affiliations: ¹ Department of Horticulture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
² Department of Food Science and Technology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
³ Department of Field Crops and Ecology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
* Author to whom correspondence should be addressed; E-Mail: siomos@agro.auth.gr
Abstract: Fresh-cut lettuce has become popular. However, the browning of the cut surface is a major problem. Phenolic compounds could increase the browning susceptibility because they are natural substrates of oxidative enzymes such as polyphenol oxidase and peroxidase. The accumulation of phenolic compounds in lettuce is affected by a range of pre- and post-harvest factors. It has been reported that UV radiation induces phenolics in plant tissues. A further potentially important factor is the time of day that the lettuce is harvested, since leaf functional attributes are known to alter diurnally, but this subject is still unresolved. Several postharvest treatments (physical or chemical) are used in the control of browning. The objective of this study was to investigate whether a reduction of phenolics in harvested lettuce could be achieved by cultivation under UV block plastic film in combination by harvesting at different times during the course of the day in order to control browning of fresh-cut product. Red (Lollo Rosso) and green leaf (Paris Island) lettuce grown under one common and two types of plastic films that varied in transparency to UV radiation (designated as UV block and UV open) were harvest during two successive days at 06:30 (beginning of day), 13:30 (mid of day) and 20:30 (end of day). At harvest, total phenolics were determined by the Folin-Ciocalteu assay. After harvest, the leaves were cut at 2 cm segments stored for up to 6 days at 4 °C in plastic boxes covered with semipermeable film. The browning of the cut edges of the lettuce segments was evaluated visually every day.

Type of Paper: Article
Title: Phenolic Content of White Asparagus Spears in Relation to Pre- and Post-Harvest Factors
Authors: Eleftherios Papoulias ¹, Anastasios S. Siomos ^1, *, Athanasios Koukounaras ¹ and Dimitrios Gerasopoulos ²
Affiliations: ¹ Department of Horticulture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
² Department of Food Science and Technology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
* Author to whom correspondence should be addressed; E-Mail: siomos@agro.auth.gr
Abstract: Convincing scientific evidence showed that fruit and vegetables are beneficial to health, due to their antioxidant constituents. Among commonly consumed vegetables in Europe, United States and Japan, asparagus is one of richest in total quantity and quality of antioxidants. The main components responsible of asparagus bioactivity are phenols and their content is affected by a range of pre- and post-harvest factors as well as by the cooking process. The objectives of this work were to evaluate phenolic content of white asparagus spears in relation to genetic material (8 cultivars), season of harvest (4 sampling dates through the 40-days harvesting period), spear diameter (12-16, 16-20, 20-24 and 24-28 mm), spear segment (0-7, 7-14 and 14-21 cm from the tip), spear tip color (white and violet), storage (0 and 6 days at 2 ^oC) and preparation for consumption (peeling and cooking) and to correlate with antioxidant activity. Total phenolics were determined by the Folin-Ciocalteu assay and antioxidant capacity by ferric reducing-antioxidant power (FRAP) assay as well as the DPPH method.

Type of Paper: Article
Title: Influence of Different Ways of Cooking on the Total and Individual Antioxidant Content of Eight Vegetables
Authors: J. Pincemail*, J. Dommes, J. O. Defraigne and C. Kevers
Affiliations: University of Liège - CHU, Dept of Cardiovascular Surgery - CREDEC B35 Sart Tilman 4000 Liège, Belgium
* Author to whom correspondence should be addressed; E-mail: J.Pincemail@chu.ulg.ac.be
Abstract: The public recommendation is to consume at least five or more servings (400 g) of fruits and vegetables daily in order to maximize prevention against cancer, cardiovascular diseases and diabetes. Such an effect of plant foods seems to be attributed to their high content in antioxidants able to decrease oxidative damages to key structures of the body including lipids, DNA and proteins. However, recent antioxidant databases have been elaborated on the basis of analytical data from raw plant material and do not, therefore, take in account the effect domestics of cooking on antioxidants. In the present study, 8 vegetables (broccoli, cabbage, potato, carrot, bean, Brussels sprout, tomato and leek) and 1 fruit (apple) were analyzed for the evolution of their total antioxidant capacity (ORAC) and their content of polyphenols (PPs) and ascorbic acid (AA) according to three way of cooking (water, steam, microwave). When compared to the dry weight, microwave produced an overall increase in polyphenols and ascorbic acid except for leek. ORAC values were either increased or remained unchanged. Water cooking was associated with negative effects on ORAC values except for potato, carrot and tomato. However, this was not systematically correlated with the evolution of PPs and AA. Steam cooking seems to well preserve the antioxidant content with respect of the three investigated parameters (except for AA in leek and Brussel sprouts). Our findings suggested that there was not an ideal way of cooking to preserve antioxidant qualities of all vegetables. Moreover, interpretation of data could be totally opposite according to the investigated parameters since no global correlation was found between ORAC, PPs and AA evolution after cooking.

Type of Paper: Article
Title: Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences
Authors: Panos V. Petrakis ^1,*, Kostas Spanos ² and Alan Feest ³
Affiliations: ¹ N. AG.RE.F., Institute for Mediterranean Forest Ecosystem Research, Laboratory of Entomology, Terma Alkmanos, 11528 Athens, Greece
² N.AG.RE.F., Forest Research Institute, 57006, Vassilika, Thessaloniki, Greece
³ Water and Management Research Centre, Faculty of Engineering, Univ. of Bristol, Bristol BS8 1TR, U.K. and ecosulis ltd, The Rickyard, Newton St. Loe, Bath, BA2 9BT, UK
* Author to whom correspondence should be addressed; E-Mail: pvpetrakis@fria.gr
Abstract: 1. Beech forests play an important role in all temperate and north Mediterranean ecosystems in Greece since they occupy extreme infertile montane soils. Until the last glacial maximum, Fagus sylvatica was confined to Southern Europe where it dominated and within the last thousand years dominated central Europe. Therefore it is suspected that beech decline is accompanied by a decline in the insect richness of beech forests.
2. We sampled four different beech forest types and we excluded coppice forests because they contained a lot of tourist insects from other deciduous trees (mainly Quercus, Ostrya, and Betulus). There were found 298 insect species in beech forests associated with the beech tree and its dead wood. Only a few were phytophagous whilst the majority included ground predators, detritivorous, and scavengers.
3. Whilst Fagus sylvatica belongs to the same family with Quercus and both genera include climax species, it exhibits great differences in terms of richness of the harbored entomofauna. Insect species that inhabit beech forests are almost one fifth of those species living in oak dominated forests besides the fact that beech is the most abundant central and north European tree.
4. There is an impressive paucity of monophagous species on beech trees and insect species are shared between co-occurring deciduous tree species and beech. For this lack the vegetation history and secondary plant chemistry have been implicated.
5. Bark biophenols from beech indicate that differences in plant secondary metabolites may be responsible for the differences in the richness of entomofauna among communities dominated by beech and other deciduous trees. Secondary plant chemistry and histochemistry may also be responsible for the mixing of beech with conifers or deciduous species.

Type of Paper: Review
Title: Biological Activities of Phenolics in Olive Oil
Authors: Sara Cicerale and Russell S. J. Keast
Affiliations: School of Exercise and Nutrition Sciences, Faculty of Health, Medicine, Nursing and Behavioural Sciences, Deakin University, Burwood, 3125, Australia
Abstract: The Mediterranean diet is associated with a lower incidence of degenerative diseases such as atherosclerosis, cardiovascular disease and certain types of cancer. These health benefits have been partially attributed to the dietary consumption of extra virgin olive oil by Mediterranean populations. Most recent interest has focused on the biologically active phenolic compounds naturally present in extra virgin olive oils. Studies (human, animal, in vivo and in vitro) have shown that olive oil phenolics have positive effects on a number of physiological processes, such as plasma lipids, oxidative damage, inflammation, platelet and cellular function and antimicrobial activity. Presumably, regular dietary consumption of extra virgin olive oil containing phenolic compounds manifests in health benefits associated with a Mediterranean diet. This paper summarizes current knowledge on the biological activities of olive oil phenolics.

Type of Paper: Review
Title: Biological Activities of Phenolics in Olive Oil
Authors: Sara Cicerale and Russell S. J. Keast
Affiliations: School of Exercise and Nutrition Sciences, Faculty of Health, Medicine, Nursing and Behavioural Sciences, Deakin University, Burwood, 3125, Australia
Abstract: The Mediterranean diet is associated with a lower incidence of degenerative diseases such as atherosclerosis, cardiovascular disease and certain types of cancer. These health benefits have been partially attributed to the dietary consumption of extra virgin olive oil by Mediterranean populations. Most recent interest has focused on the biologically active phenolic compounds naturally present in extra virgin olive oils. Studies (human, animal, in vivo and in vitro) have shown that olive oil phenolics have positive effects on a number of physiological processes, such as plasma lipids, oxidative damage, inflammation, platelet and cellular function and antimicrobial activity. Presumably, regular dietary consumption of extra virgin olive oil containing phenolic compounds manifests in health benefits associated with a Mediterranean diet. This paper summarizes current knowledge on the biological activities of olive oil phenolics.

Type of Paper: Review
Title: Flavonoids and Cardiovascular Health: A Review of Current Evidence
Authors: Sonia de Pascual-Teresa ¹, Diego A. Moreno ^2,* and Cristina García-Viguera ²
Affiliations: ¹ Departamento de Metabolismo y Nutrición, Instituto del Frío (IF), CSIC. Madrid, Spain
² Departamento de Ciencia y Tecnología de los Alimentos, Centro de Edafología y Biología Aplicada del Segura (CEBAS), CSIC, Murcia, Spain
* Author to whom correspondence should be addressed; E-Mail: dmoreno@cebas.csic.es
Abstract: Nowadays it is accepted that flavonoids present in foods and beverages, besides their technological relevance and organoleptic properties, may have potential health-promoting effects on consumers, as can be outlined from many epidemiological and experimental evidences. The beneficial biological effect of these food bioactives may be guided by two of their characteristic properties: their affinity for proteins and their antioxidant activity. Over the last 15 years, numerous publications have demonstrated that besides the demonstrated in vitro antioxidant capacity, certain phenolic compounds, such as anthocyanins, catechins, proanthocyanidins, and other non coloured flavonoids may regulate different signalling pathways involved in cell survival, growth and differentiation. In this review we will update the knowledge on the cardiovascular effects of anthocyanins, catechins, proanthocyanidins, and other non-coloured flavonoids as implied by the in vitro and clinical studies on these compounds. Nonetheless, we will also review the information on structure, distribution and bioavailability of these compounds being all necessary factors involved in the real importance of flavonoids in the human diet and the potenctial beneficial effect on cardiovascular disseases of these phytochemicals.