Nesrin Colak

Bog bilberry phenolics, antioxidant capacity and nutrient profile

Phenolics and nutrient profiles of bog bilberry (Vaccinium uliginosum L.) collected from high mountain pastures in northeast Anatolia (Turkey) were examined for the first time in this study. The major soluble sugar identified in the berry was fructose, following by glucose, and the main organic acid identified was citric acid, followed by malic acid. Eleven phenolic acids and 17 anthocyanin 3-glycosides were identified and quantified. Caffeic acid in the free and glycoside forms and syringic acid in the ester form were the major phenolic acids, and the major individual anthocyanin present in the berry was malvidin 3-glucoside (24%). The highest total phenolics and anthocyanin contents were obtained from the anthocyanin fraction in conjunction with the highest antioxidant capacity, followed by the polyphenolic and aqueous fractions, FRAP, ORAC and DPPH, in that order. Our findings can be used to compare bog bilberry with other Vaccinium berries and to help clarify the relative potential health benefits of different berries.

Comparison of phenolics and phenolic acid profiles in conjunction with oxygen radical absorbing capacity (ORAC) in berries of Vaccinium arctostaphylos L. and V. myrtillus L.

Abstract Caucasian blueberry (Vaccinium arctostaphylos L.) and bilberry (V. myrtillus L.), both native to Turkey, were evaluated for their total phenolics (TP) and anthocyanin (TAC) contents. Individual compositions of free phenolic acids and phenolic acids liberated from ester and glycoside forms were analyzed using UPLC-MS/MS. Berry extracts of each species were separated into three different fractions (sugar/acid, polyphenolic and anthocyanin) by solid phase extraction (SPE). The anthocyanin fractions of each species had the highest level of TP and TAC contents and ORAC values. Each species contained 10 phenolic acids representing each fraction, but in different quantities. The phenolic acids liberated from the esters and glycoside forms were caffeic acid and p-coumaric acid. The fractions containing phenolic acids liberated from ester and glycoside forms had a higher antioxidant capacity than that from free phenolic acids. The data suggest that both berries have potential as good dietary sources of phenolic antioxidants.

Comparison of nutrient content in fruit of commercial cultivars of eggplant (Solanum melongena L.).

Abstract Eggplant (Solanum melongena L.) is one of the most popular common major vegetable crops worldwide. This study evaluated the nutritional content of seven commercial eggplant fruits in terms of fatty acid, mineral, sugar, organic acid, amino acid and polyamine contents. The most abundant fatty acid was linoleic acid (range, 39.14-53.81%, ave. 45%), and the most abundant mineral was K (range, 1556.2-3171.6 mg/kg fw, ave. 2331.9). The major organic acid was malic acid (range, 129.87-387.01 mg/g fw, ave. 157.49), and the major sugar was fructose (range, 1242.81- 1379.77 mg/100 g fw, ave. 1350.88). The major polyamine was putrescine (11.54 and 25.70 nmol/g fw, ave. 17.86), and the major amino acid was glutamine (148.4 and 298.75 mg/100 g fw, ave. 219.74). Overall, taking into account the export potential of eggplants, these results may contribute to further studies aiming to improve other nutrient-rich varieties of eggplant in breeding programs.

Evaluation of chemical profile and antioxidant activity of Tripleurospermum insularum, a new species from Turkey

This article presents the very first phytochemical investigation on new species Tripleurospermum insularum Inceer & Hayırlıoglu-Ayaz. The volatile profile of odorous parts of the plant was analysed by GC/MS, and compounds were identified in headspace and essential oil obtained from aerial parts, representing 70.81% and 92.44% in total, respectively. The major volatiles were n-alkanes (38.43–59.22%), while essential oil was also rich in globulol (13.45%) and β-sesquiphellandrene (9.29%). The content of phenolic compounds in methanolic extract and oil was 3621.62 and 14.4 mg GAE/100 g of dry plant, respectively. Moreover, potential medicinal effects were found in mean of antioxidant activity of this plant measured by using two different assays: radical-scavenging activity and ferric-reducing activity. Samples revealed values ranging from 0.33 to 146.80 μmol TE/100 g for DPPH assay, and from 2.29 to 5414.17 μmol AAE/100 g for FRAP assay.

Synthesis, biological activity and structure activity relationship studies of novel conazole analogues via conventional, microwave and ultrasound mediated techniques

1,2,4-Triazole derivatives containing a piperazine nucleus (4a-d and 10) were prepared starting from 1-(2-methoxyphenyl)piperazine or ethyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate via several steps. The synthesis of fifteen compounds (7a-l and 13a-c), which can be considered as new analogues of azole class antifungals was performed starting from 1,2,4-triazoles (4a-d and 10) via three steps containing the condensation with 2-bromo-1-(4-chlorophenyl)ethanone, reduction of carbonyl group to alcohol and alkylation of OH group, respectively. All the reactions were examined under conventional, ultrasound and microwave irradiation conditions as green chemistry techniques, and optimum conditions were defined. The newly synthesized compounds were screened for their biological potentials including antimicrobial, antioxidant, antiurease and anti α-glucosidase activities and promising results were obtained. The enzyme inhibitory potentials of these compounds were further validated through molecular docking.