Yayınlanan Tezler
GÜZ YEMİŞİ (Elaeagnus umbellata Thunb.) MEYVE VE YAPRAK EKSTRAKTLARININ ANTİOKSİDANT VE ÜREAZ İNHİBİSYON AKTİVİTELERİNİN ARAŞTIRILMASI
Autumn olive (Elaeagnus umbellata Thunb.) is variety the angustifolia belonging to the Elaeagnus genus Elaeagnacea family. In thesis, the methanol, ethanol, water, ethyl acetate, acetone and hexane extracts of autumn olive fruit and leaves were determined spectrophotometrically component analysis, antioxidant and urease inhibition activites. The phenolics of autumn olive fruit methanol extract, the flavonoids of autumn olive fruit methanol extract, the anthocyanin of autumn olive leaf, β-carotene of autumn olive leaf hexane extract, the lycopene of autumn olive fruit hexane extracts and ascorbic acid of content autumn olive leaf were the highest found in the extracts prepared from the different solvents Butylated hydroxyanisole, butylated hydroxytoluene, trolox, tert-butylhydroquinone, vitamin E and ascorbic acid were used as a positive control in antioxidant activity assays. The extracts and the standards prepared different concentrations were increased antioxidant activity as concentration dependent and also the activities of extracts were exhibited higher than Standard antioxidants. The acetone extract of autumn olive fruit was found to be the most effective. The IC50 value of the autumn olive fruit acetone extract was 180 μg/mL in the urease inhibition test. The results of the activity and inhibition were evaluated the using ANOVA and DUNCAN tests in the SPSS (Statistical Packages for the Social Sciences; 20.0) software package and whether or not significant difference between results. In addition, the results were found to vary in direct proportion between the phenolic and flavonoid contents prepared different concentrations in the different solvent extracts and the results of different antioxidant activity tests.
NEPETA BAYTOPII HEDGE ET LAMOND BİTKİSİNİN FİTOKİMYASAL VE AKTİVİTE YÖNLENDİRMELİ İZOLASYON ÇALIŞMALARI
Nepeta species are the most important members of the Lamiaceae family, rich iniridoids and secondary metabolites and, have antioxidant, antimicrobial, diuretic, antiasthmatic, antiseptic, analgesic, anticancer, anti-inflammatory, insecticidal properties. Molecules were purified showing antioxidant, enzyme inhibitor, antibacterial, and DNA protection activities by performing activity-directed isolation studies of the aerial part of the endemic Nepeta baytopii Hedge & Lamond collected in Bingöl. The crude extract of the N. baytopii (NB) plant was obtained with a methanol:chloroform (MK) solvent mixture. The this extract applying silica gel column chromatography and first fractions were collected using n-hexane (H), chloroform (K), ethyl acetate (E), and methanol (M) solvents, respectively. Phytochemical analyzes and bioactivities of crude extract and first fractions were determined using spectroscopic techniques. Second fractions were obtained applying column chromatography the first fractions and were applied activity tests. Active fractions were determined by bioactivity guided fractions. Then, the compounds were purified using column chromatography or preparative-HPLC to bioactive fractions, and their molecular structures were elucidated by different NMR techniques. The activity results of the extract, fractions, and pure molecules were evaluated by principal component and SPSS analyses. The crude extract's total phenol and flavonoid amounts were determined as 20.24±0.15 mg GAE/g extract and 12.86±0.05 mg CE/g extract, respectively. It was noted that the main components of the extract were rosmarinic acid, cis-11- eicosanoate, and palmitate. The main component of the NBH fraction is 9,12,15- octadecatrienoic acid, its methyl ester and octadecanoic acid, methyl ester, while the NBK, NBE, and NBM is quercetin-3-glycoside. NBH fractions; showed high reducing power, H2O2 and superoxide anion scavenging, BChE, α-amylase, and tyrosinase inhibition. NBHFr4, NBHFr5, and NBHFr9 are active fractions. NBK fractions; showed effective antioxidant, BChE, and lipase inhibition, and NBKFr5 is the active fraction. NBE fractions; showed active in H2O2 scavenging and metal chelating activities, and NBEFr10 is the active fraction. NBM fractions; showed active reducing power and H2O2 scavenging activities and were recorded as active fractions of NBMFr3, NBMFr4, and NBMFr7. From the active fractions, apigenin, ixoroside, daucosterol, ursolic acid, β-sitosterol, and Molecule L were purified. The molecules' bioactivities, enzyme kinetics, and molecular docking structures were determined. As a result, it was determined that the molecules isolated by bioactivity-directed isolation studies were antioxidants against oxidative damages, regulating the activities of metabolic enzymes and protective molecules against DNA damages.