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In this study, numerous coumarin compounds were synthesized by Pechmann and Knoevenagel methods, and the substitution of the formyl group was provided by the Duff reaction. The FTIR spectra and melting points of the synthesized compounds were compared with the literature values. The structures were also confirmed by GC/MS analysis. Besides, the synthesized coumarin derivatives were compared in terms of antioxidant activity according to DPPH and CUPRAC methods. The main aim of the study is to determine the effects of substituents on antioxidant activity. © 2020, Turkish Chemical Society. All rights reserved. Part of this work is from the master’s thesis of Oktay Sin. It was supported by the Research Fund of the İstanbul University-Cerrahpaşa. Project number: FYL-2017-23395.

This study was undertaken to examine the possible cytotoxic effect of anilide and semicarbazone derivatives of (4-12) monoketo eicosanoic acids (3.125 – 100 µM) on canine mammary tumour cell line (CMT-U27) as compared with doxorubicin. Among these compounds, 8-semicarbazone eicosanoic acid (3) and 10-keto eicosanoic acid anilide (9) displayed effective cytotoxic potential against CMT-U27 and IC50 concentrations were recorded at 1.952 µM and 54.00 µM, respectively.

Biologically active compounds containing nitrogen, natural molecules and drugs are important for organic synthesis. Mannich reaction is one of the most common methods used for the synthesis of these compounds. Bi(NO3)3 was used as an efficient catalyst for the one-pot three-component Mannich reactions of ketones with different aromatic amines and aromatic aldehydes at room temperature. It is a good method to prepare β-aminocarbonyl compounds in excellent yield. The high efficiency using simple starting materials and a catalytic amount of a reusable catalyst is especially noteworthy. © 2019, Turkish Chemical Society. All rights reserved. Istanbul Üniversitesi: 57459 This work was supported by Scientific Research Projects Coordination Unit of Istanbul University. Project number: 57459.

New Schiff bases were synthesized by condensation of methyl-5-(furan-2-yl)-5-oxopentanoate, methyl-4-(furan-2-yl)-4-oxobutanoate, methyl-5-(thiophene-2-yl)-5-oxopentanoate, and methyl-4-(thiophene-2-yl)-4-oxobutanoate with p " role="presentation"> p p p -anisidine and n " role="presentation"> n n n -butylamine. The structures of these synthesized compounds were clarified on the basis of elemental analysis, IR, 1 " role="presentation"> 1 1 ^{1} H NMR, 13 " role="presentation"> 13 13 ^{13} C NMR, and GC-MS spectroscopic techniques. In addition, antioxidant activity of the synthesized compounds was evaluated on the basis of DPPH radical.

Successive reaction of long chain w-1, w-2, w-4 and w-5 hydroxycarboxylic acids 1a-1e with a cyanuric chloride (CC) and triethylamine afforded the corresponding racemic lactones 2a-2e in high yields. Optically pure R lactones 4a-4e were synthesized stereoselectively by porcine pancreas lipase-catalysed resolution of racemic 2a-2e. The resolution conditions were investigated, determined and optical rotations were measured. The mentioned chiral lactones were synthesized by this method for the first time. The obtained racemic and chiral lactones were analysed by NMR, IR, Mass, optical rotation and C,H analysis.

In this work eight different crude biocatalysts together with six Lewis and three Bronsted acids were used for asymmetric aldol reactions of aromatic, heteroaromatic, cyclic, and acyclic six ketones and eleven aldehydes. Optimum reaction conditions were determined by changing temperature and enzyme, ketone, aldehyde, solvent, cofactors types, amounts, and ratios. PPL (porcine pancreatic lipase) of animal and AL-AN (amano lipase A from Aspergillus niger) of fungal origins were the best ones and compared with each other. CoCl2 was the best cofactor and catalyzed the enzymatic aldol reaction better than without cofactor. CoCl2 was not used before for enzymatic aldol reactions. The method in this study, using crude biocatalysts (PPL or AL-AN) and CoCl2 in acetonitrile–water was found as an conventionally useful biocatalytic way for asymmetric aldol reaction and has given better ee values than in the literature.

In this study, we investigated the antioxidant capacity and total phenolic and flavonoid contents of aqueous of Ziziphus jujuba from Çanakkale. The antioxidant capacity of the aqueous extract from Ziziphus jujuba fruits was measured by various assays including DPPH radical scavenging, nitric oksit scavenging activity, iron chelating activity and reducing power. Total phenolic and flavonoid content of the extract were measured as pyrocatechol and catechin equivalent respectively, 15.21 ± 1.05 μg pyrocatechol and 2.05 ± 0.45 μg catechin. It is especially important to support the cultivation of this fruit, which is very rich in phenolic and flavonoid substances, and to increase its use among the people. Data suggested that Ziziphus jujuba grown in Çanakkale may be importance source as natural antioxidant when it was compared with standarts and old articles about the same methods., Bu çalışmada; Çanakkale’de yetişen Ziziphus Jujuba adlı meyvenin sulu ekstresinin antioksidan aktivitesi ve toplam fenolik, flavonoid ve antosiyanin madde miktarları tayin edildi. Antioksidan kapasite tayini için; DPPH radikalini süpürme aktivitesi, nitrik oksit giderici etkisi, Fe2+ kelatlama aktivitesi ve indirgeyici gücü belirlendi. Ekstredeki toplam fenolik ve flavonoid madde miktarları sırasıyla, 1 mg hünnap meyvesinin sulu ekstresinde 15.21 ± 1.05 μg pirokateşole eşdeğer ve 2.05 ± 0.45 μg kateşine eşdeğer olarak bulundu. Özellikle fenolik ve flavonoid madde açısından oldukça zengin olan bu meyvenin tarımının desteklenmesi ve halk arasında kullanımının arttırılması önemlidir. Çanakkale’de yetişen Ziziphus Jujuba, standartlar ve yapılmış bazı çalışmalarla karşılaştırıldığında doğal bir antioksidan madde kaynağıdır.

Fifteen novel aryl, substituted aryl and heteroaryl γ-hydroxy- (2a-e), γ-methoxyimino- (3a-e), and γ-benzyloxyimino- (4a-e) butyric acid methyl esters were investigated for their enzyme inhibition, and the synthesis of 10 compounds (3a-e, 4a-e) is given in this study. The other five compounds (2a-e) were synthesized before in another study. Compounds 3a-e and 4a-e were synthesized in this work as original compounds and characterized by 1 H and 13 C NMR, IR, mass, and elemental analyses. Their (E/Z)-isomerisation ratios were analyzed by 1 H and 13 C NMR. All of them are of pure (E)-configuration. Due to the literature survey, the elastase inhibition activity was not studied for these compounds. Elastase inhibition ability was investigated in this work for five γ-hydroxy- (2a-e), five γ-methoxy- (3a-e), and five γ-benzyloxyimino- (4a-e) butyric acid methyl esters. All these 15 compounds showed elastase inhibition activity. Compound 2b was the best one and exhibited a better activity than the standard ursolic acid whereas compound 2a worked like the standard. All these compounds can be novel elastase inhibitor agents in the pharmaceutical and cosmetic industries.

The preparation of novel 3-, 4-, 6-, and 13-amino-tetradecanoic acid methyl esters (2a-d) obtained by the reduction of 3-, 4-, 6-, and 13-oximino-tetradecanoic acid methyl esters (1a-d), was investigated. Oximino esters were reduced to afford the corresponding amino esters using NaBH4-ZrCl4 reducing system with good yields (58-82%). On the other hand, the reduction of oximino esters with LiAlH4 and BH3. THF gave the corresponding novel 3-, 4-, 6-, and 13-oximino alcohols (3a-d), and 3-, 4-, 6-, and 13-amino alcohols (4a-d) respectively with good chemical yields.

The preparation of novel 3-, 4-, 6-, and 13-amino-tetradecanoic acid methyl esters (2a–d) obtained by the reduction of 3-, 4-, 6-, and 13-oximino-tetradecanoic acid methyl esters (1a–d), was investigated. Oximino esters were reduced to afford the corresponding amino esters using NaBH4–ZrCl4 reducing system with good yields (58–82%). However, the reduction of oximino esters with LiAlH4 and BH3. Tetrahydrofuran gave the corresponding novel 3-, 4-, 6-, and 13-oximino alcohols (3a–d), and 3-, 4-, 6-, and 13-amino alcohols (4a–d) respectively with good chemical yields.

In this study, it is aimed to investigate the chemical composition of the essential oils, antioxidant activity, and polyphenol content of methanol extracts of M.comminus L. leaves and berries. M.comminus L. Plant was collected from Yalova, Marmara region of Turkey. Its essential oil was prepared by hydrodistillation in a Clevenger-type apparatus in 0.5%. The chemical composition of the essential oil was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC–MS), using two columns with stationary phases of different polarity (polar ZB-WaxMS/apolar ZB-5MS). On both columns monoterpenes were determined to be the dominant compounds. The myrtenyl acetate, α-pinene, 1,8-cineole, linalool, and limonene were the remarkable substances. As polyphenol compounds, the flavanoids and anthocyanidins in leaves and berries were detected by HPLC and furthermore, their antioxidant activities were studied with DPPH, Cuprac and Folin – Ciocalteu method of the methanolic extracts.

The aim of this study was to investigate the chemical composition of Mentha pulegium L.’s essential oils from Bodrum, Turkey and to compare it with the literature values. The essential oils in this study were prepared by two different methods, by Clevenger and Steam Distillation. The yields of the essential oils, obtained by Clevenger and steam distillation were 1.6 % and 1.1 %, respectively. The composition of the essential oils were analysed by GC and GC-MS using Carbowax-20M as polar and DB-5 as apolar columns. The headspace analysis of this plant was examined, too. The basic components of steam distillation method on apolar DB-5 column, were isomenthone (42.1 %), pulegone (28.9 %), piperitenone (11.8 %) and piperitone (11.6 %). Analysis of Clevenger type method on the same column gave pulegone (34.6 %), piperitenone (31.4 %), isomenthone (17.9 %) and piperitone (9.7 %) as main components. The major components of headspace analysis of Mentha pulegium L. on DB5 column were isomenthone (52.6 %),...