Anthocyanins have been shown to possess specific antioxidant capacities, which may provide an underlying protective effect against many chronic diseases . Although the antioxidant capacity of anthocyanins has been well established, less is known about the extent to which specific anthocyanin composition affects total antioxidant capacity . The aim of the present study was to compare the antioxidant capacity of two different soft fruits, blackcurrant and grape, which have distinctly different anthocyanin profiles. The anthocyanin profiles of grape and blackcurrant were characterized by HPLC/MS coupled with a diode array detector. Results showed that blackcurrant contained four predominant anthocyanins, cyanidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-rutinoside, and delphinidin 3-rutinoside . In contrast, malvidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and peonidin 3- glucoside were the major anthocyanins found in grape . The concentration of individual anthocyanins in all berries was quantified with HPLC/UV using cyanidin 3-glucoside as an external standard . Finally, results showed a greater (p<0.05) antioxidant capacity of blackcurrant compared to grape. The total antioxidant capacity of crude extracts from each was measured by Oxygen Radical Absorbance Capacity (ORAC) and ABTS assays. Anthocyanin antioxidant capacity index (AACI), derived from the product of antioxidant (ORAC) activity for each of major anthocyanin present in blackcurrant and grape, was also used to determine whether the antioxidant capacity of crude anthocyanin fractions represents either the sum total anthocyanin content or, alternatively, a synergy between different anthocyanins components . Our results indicated that a plausible potential synergy between anthocyanin components in regards to ORAC antioxidant capacity existed in blackcurrant and grape semi-purified anthocyanin extracts. Furthermore, it could be concluded that both total anthocyanin content as well as the composition of individual anthocyanins in soft fruits is important to assess total antioxidant capacity of different berry sources .

Anthocyanins have been shown to possess specific antioxidant capacities, which may provide an underlying protective effect against many chronic diseases . Although the antioxidant capacity of anthocyanins has been well established, less is known about the extent to which specific anthocyanin composition affects total antioxidant capacity . The aim of the present study was to compare the antioxidant capacity of two different soft fruits, blackcurrant and grape, which have distinctly different anthocyanin profiles. The anthocyanin profiles of grape and blackcurrant were characterized by HPLC/MS coupled with a diode array detector. Results showed that blackcurrant contained four predominant anthocyanins, cyanidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-rutinoside, and delphinidin 3-rutinoside . In contrast, malvidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and peonidin 3- glucoside were the major anthocyanins found in grape . The concentration of individual anthocyanins in all berries was quantified with HPLC/UV using cyanidin 3-glucoside as an external standard . Finally, results showed a greater (p<0.05) antioxidant capacity of blackcurrant compared to grape. The total antioxidant capacity of crude extracts from each was measured by Oxygen Radical Absorbance Capacity (ORAC) and ABTS assays. Anthocyanin antioxidant capacity index (AACI), derived from the product of antioxidant (ORAC) activity for each of major anthocyanin present in blackcurrant and grape, was also used to determine whether the antioxidant capacity of crude anthocyanin fractions represents either the sum total anthocyanin content or, alternatively, a synergy between different anthocyanins components . Our results indicated that a plausible potential synergy between anthocyanin components in regards to ORAC antioxidant capacity existed in blackcurrant and grape semi-purified anthocyanin extracts. Furthermore, it could be concluded that both total anthocyanin content as well as the composition of individual anthocyanins in soft fruits is important to assess total antioxidant capacity of different berry sources .

Anthocyanins have been shown to possess specific antioxidant capacities, which may provide an underlying protective effect against many chronic diseases . Although the antioxidant capacity of anthocyanins has been well established, less is known about the extent to which specific anthocyanin composition affects total antioxidant capacity . The aim of the present study was to compare the antioxidant capacity of two different soft fruits, blackcurrant and grape, which have distinctly different anthocyanin profiles. The anthocyanin profiles of grape and blackcurrant were characterized by HPLC/MS coupled with a diode array detector. Results showed that blackcurrant contained four predominant anthocyanins, cyanidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-rutinoside, and delphinidin 3-rutinoside . In contrast, malvidin 3-glucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and peonidin 3- glucoside were the major anthocyanins found in grape . The concentration of individual anthocyanins in all berries was quantified with HPLC/UV using cyanidin 3-glucoside as an external standard . Finally, results showed a greater (p<0.05) antioxidant capacity of blackcurrant compared to grape. The total antioxidant capacity of crude extracts from each was measured by Oxygen Radical Absorbance Capacity (ORAC) and ABTS assays. Anthocyanin antioxidant capacity index (AACI), derived from the product of antioxidant (ORAC) activity for each of major anthocyanin present in blackcurrant and grape, was also used to determine whether the antioxidant capacity of crude anthocyanin fractions represents either the sum total anthocyanin content or, alternatively, a synergy between different anthocyanins components . Our results indicated that a plausible potential synergy between anthocyanin components in regards to ORAC antioxidant capacity existed in blackcurrant and grape semi-purified anthocyanin extracts. Furthermore, it could be concluded that both total anthocyanin content as well as the composition of individual anthocyanins in soft fruits is important to assess total antioxidant capacity of different berry sources . / Land and Food Systems, Faculty of / Graduate

Cardiovascular disease (CVD) claims more lives than any other disease in the world. Although numerous biological pathways share the blame, ventricular tachyarrhythmia (VT) is estimated to account for ~25% of all CVD deaths. A complete understanding of the molecular mechanisms underlying VT is unknown but recent studies have linked VT to improper calcium handling in the heart (canine). The principle calcium regulator in the muscle cell is the calcium ion release channel (aka RyR). Numerous endogenous and exogenous compounds can affect the way the RyR regulates calcium. In particular, abnormal levels of oxidants (reactive oxygen species) can oxidize critical thiol groups on the RyR and modulate its activity. Interestingly, high levels of oxidants are also associated with numerous bodily disease states including cancers, muscle fatigue/failure, and CVD. In this thesis, two important dietary antioxidant compounds, the anthocyanidins pelargonidin and delphinidin, are evaluated for their effects on regulating the transport of calcium through the calcium release channel (RyR1) of the sarcoplasmic reticulum of skeletal muscle. Pelargonidin and delphinidin are structurally similar with delphinidin only differing from pelargonidin by the addition of two hydroxyl groups. Both compounds undergo time dependent structural changes in aqueous solutions at physiological pH and a mixture of more than four structures of each compound can be present in solution simultaneously. Pelargonidin and delphinidin show distinct differences in their calcium flux regulating effect on the RyR1. Delphinidin stimulates calcium flux and RyR1 activity where as pelargonidin can cause both inhibition and stimulation of the RyR1. The strength of stimulation and inhibition of calcium transport through the RyR by delphinidin and pelargonidin may be attributed to the structural and chemical changes in those compounds that occur in solutions near physiological pH and the subsequent chemical characteristics of the diverse set of structures that are simultaneously present in solution.

L'obésité et ses complications métaboliques comme le syndrome métabolique (SM) deviennent des épidémies mondiales qui partagent une composante commune qu’est l'inflammation chronique. Les acteurs principaux de cette inflammation sont les lymphocytes T. L’utilisation des polyphénols capables de moduler les fonctions de lymphocytes T pour lutter contre les maladies métaboliques inflammatoires fait l’objet de nombreuses investigations. Dans cette étude, nous avons analysé l'effet de la delphinidine, un anthocyane connu pour préserver l'intégrité de l'endothélium par un mécanisme dépendant au récepteur aux oestrogènes alpha (ERα), sur la prolifération, l’apoptose et la différentiation de lymphocytes T isolés à partir de sujets sains et de patients atteints de SM. La delphinidine diminue la prolifération et l’apoptose de lymphocytes T isolés à partir de sujets sains et stimulés par différents agents mitogènes et proapoptotiques, respectivement. Par ailleurs, la delphinidine inhibe la différenciation des lymphocytes vers des profilsTh1, Th17 et Treg, sans affecter le profil Th2. Enfin, la delphinidine inhibe la prolifération, l’apoptose et la différenciation des lymphocytes T isolés à partir de patients présentant des risques cardiovasculaires associés au SM. Les mécanismes moléculaires mis en jeu ont été identifiés, avec l’implication d'ERα, d'ERK1/2, de NFAT et d'HDAC en relation avec le signal calcique. Nos résultats suggèrent que la delphinidine, en agissant sur ERα, via des cibles cellulaires multiples, pourrait représenter une nouvelle approche pour traiter les troubles métaboliques inflammatoires chez les patients présentant des facteurs de risque cardiovasculaire. / Obesity and its metabolic complications like metabolic syndrome (MetS) are becoming worldwide epidemics which share a common component of chronic low-grade inflammation. T lymphocytes play a central role in the triggering of this inflammatory process. Modulation of T lymphocytes functions by using polyphenols, as a possible approach to alleviate chronic inflammatory metabolic diseases has become the subject of many scientific investigations. Here, we analyzed the effect of delphinidin, an anthocyanin known to possess vasculoprotection properties, via an estrogen receptor alpha (ERα)-dependent mechanism, on proliferation, apoptosis and differentiation of T lymphocytes from healthy subjects and MetS patients. We found that delphinidin decreased proliferation and apoptosis of T lymphocytes from healthy subjects stimulated by different mitogen and apoptotic agents, respectively. Further, delphinidin suppressed the differentiation of hese cells toward Th1, Th17 and Treg without affecting Th2 subsets. Interestingly, delphinidin inhibited proliferation, apoptosis and differentiation of T cells taken from patients with cardiovascular risks associated with MetS. We also identified the molecular mechanism involved, with the implication of ERα, ERK1/2, NFAT and HDAC pathways in relation with calcium signaling. Together, we propose that delphinidin by acting on ERα, via multiple cellular targets, may represent a new approach in the treatment of chronic inflammatory metabolic disorders caused by excessive T lymphocyte responses, in with cardiovascular risk factors.

The base-catalysed reaction of 4H-pyran-4-one with a range of nucleophiles, namely diethyl malonate, ethyl acetoacetate, nitromethane, acetylacetone and ethyl cyanoacetate, was developed as a reliable, high yielding method for the preparation of para-substituted phenols. The methodology was extended to include the use of the substituted pyranones, maltol, 2,6-dimethyl-4H-pyran-4-one and diethyl chelidonate. Reactions were studied using conventional heating methods and microwave irradiation. Microwave irradiation had definite beneficial effects, with improved yields, reduced reaction times and cleaner reaction profiles. The potential of this methodology was examined for the regioselective placement of ¹³C-atoms into benzene rings using ¹³C-labelled nucleophiles or ¹³C-labelled 4H-pyran-4-ones. [3,5-13C₂]4H-Pyran-4-one and [2,6-13C₂]4H-pyran-4-one were prepared from various ¹³C-labelled versions of triethyl orthoformate and acetone. This methodology was applied to the synthesis of [1,3,5-¹³C₃]gallic acid, via the base-catalysed reaction of [3,5-¹³C₂]4H-pyran-4-one with diethyl [2-¹³C]malonate, followed by subsequent transformations to yield [1,3,5-¹³C₃]gallic acid. The preparation of [2-¹³C]phloroglucinol was carried out via [2-¹³C]resorcinol, with regioselective placement of a single ¹³C-atom into the aromatic ring. This was accomplished from non-aromatic precursors, with the source of the ¹³C-atom being [¹³C]methyl iodide. The key step in this synthesis was the introduction of the third hydroxyl group, which was achieved using a modified iridium-catalysed C-H activation/borylation/oxidation procedure. The scope of an existing C-H activation/borylation reaction was modified and expanded to include a range of protected resorcinol derivatives. A catalyst system was developed which allowed high conversion to the intermediate arylboronic acids, followed by oxidation using aqueous Oxone® to yield the corresponding phenols. Finally, to demonstrate the potential of these new methods for application in the synthesis of isotopically labelled natural products and polyphenols, the syntheses of ¹³C-labelled anthocyanins were studied. A route was developed that could be applied to the synthesis of either cyanidin-3-glucoside or delphinidin-3-glucoside. Only the final coupling/cyclisation step to yield the desired anthocyanin targets remains to be carried out.