Kromon türevi Schiff bazı metal komplekslerinin sentezi ve katekol oksidaz benzeri aktivitelerinin incelenmesi
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Dosyalar
Tarih
2017
Yazarlar
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Yayıncı
Hatay Mustafa Kemal Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, doğal bir furanokromon olan visnagin, Hatay bölgesinde yabani olarak yetişen Ammi visnaga L. bitkisinden izole edildi. Visnagin, daha sonra H2SO4/K2Cr2O7 yardımıyla ve 70-80ºC'de 6-formil-7-hidroksi-5-metoksi-2-metilbenzopiran-4-on bileşiğine yükseltgendi. Visnagin ve onun yükseltgenme ürünü olan bileşiğin yapıları literatürde verilmiş olan Rf ve erime noktası değerleri ile karşılaştırma yapılarak doğrulandı. Bir simetrik yapıda dört dişli (H2L1) ve bir de asimetrik yapıda dört dişli (H2L2) olmak üzere iki adet Schiff bazı ligandı, visnaginin yükseltgenme ürünü (6-formil-7-hidroksi-5-metoksi-2-metilbenzopiran-4-on) ile sırasıyla 2,3-diaminonaftalin ve 4-nitro-o-fenilendiamin bileşiklerinin kondenzasyon reaksiyonları sonucu elde edildi. Schiff bazlarının yapıları elementel analiz ve FT-IR, NMR, Kütle ve UV-Vis spektroskopi teknikleriyle aydınlatıldı. Bu Schiff bazı ligandlarının Cu(II) ve Fe(II) kompleksleri ise, ligandlar ve uygun metal tuzlarının 1:1 oranında geri soğutucu altında kaynatılması ile elde edildi. Bu kompleksler, FT-IR, UV-Vis ve Kütle spektroskopisi, elementel ve AAS analizleri, magnetik duyarlılık, TGA ve molar iletkernlik metotları yardımı ile karakterize edildi. Sentezlenen komplekslerin katekol oksidaz benzeri aktiviteleri model substrat olarak 3,5-di-tert-bütilkatekol (3,5-DTBC) kullanılarak, oda sıcaklığında, metanol ve dimetilsülfoksit ortamlarında araştırıldı. Katalitik aktivite çalışmaları, tüm komplekslerin katekol oksidaz aktivite gösterdiklerini doğruladı. Hesaplanan kinetik parametreler ise, Fe(II) komplekslerinin Cu(II) komplekslerinden daha iyi bir katalitik aktiviteye sahip olduklarını, protik solventlerin 3,5-DTBC'nin yükseltgenmesi için aprotik solventlere göre daha iyi bir tercih olduğunu ve elektron çekici grupların katalitik aktiviteyi azalttığını gösterdi.
In this study, visnagin, a natural furanochromone, isolated from Ammi visnaga L. which has been growing in Hatay region as a wild plant. Visnagin was oxidized to 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one by using H2SO4/K2Cr2O7 at 70-80ºC. The structures of visnagin and its oxidation product were confirmed by comparing the Rf value and the melting point of the compound with the values reported in the literature. A symmetric tetradentate Schiff base ligand (H2L1) and an assymmetric tetradentate Schiff base ligand (H2L2) were synthesized by condensation reaction of oxidation product of visnagin (6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one) with 2,3-diaminonaphthalene and 4-nitro-o-phenylenediamine, respectively. The structure of Schiff bases were characterized by elemental analyses and spectroscopic methods such as FT-IR, NMR, Mass and UV-Vis spectroscopy. The synthesis of Cu(II) and Fe(II) complexes of Schiff base ligands was carried out by refluxing of appropriate metal salts with the ligands at 1:1 ratio. They were characterized by FT-IR, UV-Vis and Mass spectroscopy, elemental and AAS analyses, magnetic susceptibility, TGA, molar conductivity methods. The catechol oxidase-like activity of the complexes synthesized was investigated using 3,5-di-tert-butylcatechol (3,5-DTBC) as a model substrate in methanol and in dimethylsulfoxide at room temperature. The catalytic activity studies revealed that all complexes showed catechol oxidase activity. According to the calculated kinetic parameters, Fe(II) complexes have more significant catalytic activity than Cu(II) complexes, protic solvents are observed to be a better choice than aprotic solvents for the oxidation of 3,5-DTBC and electron withdrawing substituents reduced the catalytic activity.
In this study, visnagin, a natural furanochromone, isolated from Ammi visnaga L. which has been growing in Hatay region as a wild plant. Visnagin was oxidized to 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one by using H2SO4/K2Cr2O7 at 70-80ºC. The structures of visnagin and its oxidation product were confirmed by comparing the Rf value and the melting point of the compound with the values reported in the literature. A symmetric tetradentate Schiff base ligand (H2L1) and an assymmetric tetradentate Schiff base ligand (H2L2) were synthesized by condensation reaction of oxidation product of visnagin (6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one) with 2,3-diaminonaphthalene and 4-nitro-o-phenylenediamine, respectively. The structure of Schiff bases were characterized by elemental analyses and spectroscopic methods such as FT-IR, NMR, Mass and UV-Vis spectroscopy. The synthesis of Cu(II) and Fe(II) complexes of Schiff base ligands was carried out by refluxing of appropriate metal salts with the ligands at 1:1 ratio. They were characterized by FT-IR, UV-Vis and Mass spectroscopy, elemental and AAS analyses, magnetic susceptibility, TGA, molar conductivity methods. The catechol oxidase-like activity of the complexes synthesized was investigated using 3,5-di-tert-butylcatechol (3,5-DTBC) as a model substrate in methanol and in dimethylsulfoxide at room temperature. The catalytic activity studies revealed that all complexes showed catechol oxidase activity. According to the calculated kinetic parameters, Fe(II) complexes have more significant catalytic activity than Cu(II) complexes, protic solvents are observed to be a better choice than aprotic solvents for the oxidation of 3,5-DTBC and electron withdrawing substituents reduced the catalytic activity.
Açıklama
Anahtar Kelimeler
Kimya, Chemistry
