Nusret Genc

Isolation and identification of a new neo-clerodane diterpenoid from Teucrium chamaedrys L.

Teucrium chamaedrys L. is an aromatic and medicinal plant used as traditional medicine. Aerial parts of the plant material were dried and extracted with hexane–dichloromethane (extract 1), ethyl acetate–dichloromethane (extract 2) and methanol–dichloromethane (extract 3) in a ratio of 1:1 at rt successively. The solvents were evaporated to give crude extracts. Extract 1 was suspended in water at 60°C then partitioned successively with hexane and ethyl acetate to give hexane and ethyl acetate portions. After the column chromatography (silica gel) of ethyl acetate extract, one new and four known compounds were isolated. The new compound was named as 1(12S,18R)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,l2-olide-l8,l9-hemiacetal (teuchamaedryn D) (4). The known compounds were teucrin A (1), dihydroteugin (2), teucroxide (3), syspirensin A (5). The chromatographic methods were also applied for extract 3 to isolate verbascoside (6) and teucrioside (7). The structure of isolated compounds was elucidated by spectroscopic methods including LC-TOF/MS, 1D NMR and 2D NMR.

Changes in flavonoid and phenolic acid contents in some Rosa species during ripening

In this study, fruits of Rosa dumalis, R. canina, and R. villosa were cultivated and harvested at six different time points based on colour changes during the ripening period. Phenolic acid and flavonoid contents in fresh hypanthium were determined by HPLC-DAD. Derivatives of organic acid (gallic, caffeic, p-coumaric, and ferulic acids) and flavonoid (catechin, eriocitrin, rutin, apigenin, quercetin, apigenin-7-O-glucoside and kaempferol) were quantified using calibration curves. Phenolic acid contents of the Rosa species increased nonlinearly depending on the harvesting time. The highest amount of catechin was found at the fifth harvest time point (H-5) ranged from 323 to 472mgkg-1. The highest level of caffeic acid content was found in the R. dumalis ranged from 24 to 77mgkg-1. The total amount of flavonoid increased up to the fifth harvest time point (H-5), whereas the amount of total phenolic acid tended to decrease until the same harvest period.

Antioxidant activity of an anatolian herbal tea—Origanum minutiflorum: isolation and characterization of its secondary metabolites

ABSTRACT Origanum species are significant aromatic and medicinal plants used in food and pharmaceutical industries. Isolation of bioactive compounds was executed on n-butanol extract to yield the compounds responsible for the activities. Tricosan-1-ol (1), (8E,16E)-tetracosa-8,16-diene-1,24-diol (2), azepan-2-one (3), 3,4-dihydroxybenzoic acid (4), apigenin (5), eriodictyol (6), globoidnan-A (7), luteolin (8), rosmarinic acid (9), apigenin-7-O-glucuronide (10), and vicenin-2 (11) were isolated by chromatographic methods (column chromatography and semi-preparative High Performance Liquid Chromatography (HPLC) and structures were elucidated on the basis of spectroscopic techniques including 1D/2D nuclear magnetic resonance (NMR) and Liquid chromatography/Time-of-flight/Mass spectrometry (LC-TOF/MS). The isolated compounds and extracts were applied for antioxidant assays including 1,1-diphenyl-2-picrylhydrazyl (DPPH•) scavenging, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+) scavenging, reducing power, and cuprac techniques. 3,4-Dihydroxy benzoic acid (4), eriodictyol (6), luteolin (8), and rosmarinic acid (9) revealed the considerable antioxidant activities.

Antiproliferative, antioxidant, computational and electrochemical studies of new azo-containing Schiff base ruthenium(II) complexes

A new series of ruthenium(II) complexes 7–11 containing the –NN– group are synthesized and characterized via elemental analysis, and IR, UV-visible and 1H–13C NMR spectroscopy. The solid-state structures of 2, 6 and 9 are determined by single crystal X-ray diffraction studies. The antiproliferative activities of the Schiff base ligands and their ruthenium(II) complexes are investigated in vitro against non-small cell lung cancer cells (H2126), prostate adenocarcinoma cells (PC3) and breast cancer cells (MCF7). The cell proliferation tests are performed as dose-dependent assays at eight concentrations, and 5-fluorouracil is used as the positive control. Compounds 4 and 5 show higher antiproliferative activities against PC3 cells than the other synthesized compounds. Furthermore, the antioxidant capacities of the Schiff base ligands and their ruthenium(II) complexes are investigated in vitro via ferric reduction power, DPPH free radical, and ABTS cation radical scavenging activity tests. The radical scavenging activities of complexes 7–11 are found to be higher than BHT, BHA, and Trolox, which are used as positive controls. The antioxidant activity of the complexes is found to be 30–150 fold higher than the ligands. According to obtained results, the ruthenium complexes in this study may be used as antioxidant agents in the food, drug and cosmetic industries.

Isolation and Identification of Functional Components in Seed of Cherry Laurel (Laurocerasus officinalis Roem.) and Investigation of Their Antioxidant Capacity

In generally, bioactive compounds are named functional compounds. There is trend to investigate of isolation, identification and biological activities of functional compounds from natural sourcs in recent years. The aim of this work is to investigate functional compounds analysis and their antioxidant capacity of cherry laurel seed. In this work some functional compounds were isolated by chromatographic techniques and identification of their structure by spectroscopic (NMR, IR, UV, etc.) methods. Amygdalin, prunasin, and β-sitosterol compounds were isolated. These compounds firstly were isolated from cherry laurel seed. The antioxidant capacities of these compounds have been investigated with some different antioxidant methods. In this study, it has been shown that reduction power activities of these compounds were higher than BHA and lower than BHT and α-tocopherol.