Publication: 4- amino- 3,5- dimetil pirazol’den türeyen bazı tiyoüre bileşiklerinin in vivo metabolizması
Abstract
1. ÖZET 4-AMİNO- 3, 5 - DİMETİL PİRAZOL’ DEN TÜREYEN BAZI TİYOÜRE BİLEŞİKLERİNİN İN VİVO METABOLİZMASI Tiyoüre türevleri son yıllarda gösterdikleri antitüberküler, antibakteriyel, antifungal, anti HIV, antihipertansif ve özellikle antikonvulsan gibi önemli biyolojik aktiviteler nedeniyle dikkat çekmektedirler. Ancak çok sayıda biyolojik aktivite çalışması olmasına rağmen bu bileşiklerin metabolizmaları ile ilgili yayınlar oldukça az sayıdadır. Bu nedenle daha önce tarafımızdan sentezlenen ve antikonvulsan aktivite gösteren N-fenil–N'-(3,5-dimetilpirazol-4-il)tiyoüre üzerinde in vivo metabolizma çalışması yapılmıştır. Bu araştırmada substratın plazmada büyük ölçüde değişmeden kaldığı tespit edilmiştir. Ayrıca düşük konsantrasyonda bilinmeyen iki metabolit daha saptanmıştır. Bu çalışmada aromatik halka üzerinde sübstitüent taşıyan tiyoüre bileşikleri seçilerek in vivo metabolizma yolları ayrıntılı olarak incelenmiştir. Substratlar, N-(4-fluoro/ klorofenil)–N'-(1,3,5-trimetilpirazol-4-il)tiyoüre (T2 ve T3) ve ilgili metabolitleri sentez edilerek yapı tayinleri elemental ve spektral analizler ile yapılmıştır. Substratlar %5’lik arap zamkında çözülmüş ve sıçanlara 100 mg/ kg doz ve 0.1 ml hacimde olacak şekilde intraperitonal olarak uygulanmıştır. Kan örnekleri substrat verilmeden ve verildikten sonra 30 dakika, 1., 2., 4., 8., 12. ve 24. saatlerde alınmıştır. Substrat ve ilgili metabolitlerinin kromatografik ayrımları Hichrom chromasil C18 kolonda yapılmıştır. En uygun mobil faz bileşimi metanol ve suyun değişik oranlardaki karışımlarında sağlanmıştır. Tiyoüre bileşiklerinin metabolizma çalışmalarında N-dealkilasyon metabolitleri olan N-(4-fluoro/ klorofenil–N'-(3,5-dimetilpirazol-4-il)tiyoüre (T1 ve T4) ve plazmada değişmeden kalan substrat (T2 ve T3) referans standartları ile kıyaslanarak HPLC-UV/ DAD ile tespit edilmiştir. Ayrıca plazmada desülfürasyon metabolitleri saptanmamıştır. Bu bulgular farmakolojik aktif olan tiyoüre fonksiyonel grubunun desülfürasyon ile üreye dönüşmeyerek değişmeden plazmada kaldığını kanıtlamıştır 2.
IN VIVO METABOLISM OF SOME THIOUREAS COMPOUNDS FROM 4- AMINO-3,5 – DIMETHYL PYRAZOLE Thiourea derivatives have attracted attention during the last decades due to their significant biological activities as antitubercular, antibacterial, antifungal, anti-HIV-I, antihypertensive as well as good anticonvulsant properties. However among numerous studies, there are very few concerning the metabolism of thioureas. We therefore investigated the in vivo metabolism of N-phenyl-N'-(3,5-dimethylpyrazole-4-yl)thiourea as potent anticonvulsant. In this investigation, the previous results had showed that the substrate was metabolized largely unchanged in the plasma. Only two unknown metabolites were determined with low concentration. So we choosed the bearing substituted phenyl ring at thiourea compounds and in vivo metabolism pathway was studied in details in this study. Substrates, N-(4-fluoro/ chlorophenyl)-N'-(1,3,5-trimethylpyrazole-4-yl)thioureas (T2 and T3), and their possible metabolites were synthesized and the structures of the compounds were elucidated by spectral and elemental analysis. Substrates were dissolved in 5% gum arabica and administered intraperitoneally at 100 mg/ kg doses in approximately 0.1 ml volume. Blood samples were withdrawn before and 30 min, 1., 2., 4., 8., 12. and 24. h after dosing. Chromatographic separation of substrate and its metabolites were performed using a Hichrom chromasil C18 column (150 mm x 4.6 mm i.d., 5μm particle size), made of stainless steel. The optimal composition of the mobil phase was achieved by different mixtures of pure methanol and water. From the biotransformation of these thiourea compounds, N-dealkylation metabolites N-(4-fluoro/ chlorophenyl)-N'-(3,5-dimethylpyrazole-4-yl)thioureas (T1 and T4) were identified together with unchanged substrate (T2 and T3) in plasma by comparing their to reference standards by HPLC-UV/ DAD. Furthermore the desulfuration metabolites were not determined in plasma samples. These results proved that pharmacological active of thiourea functional group was unchanged in plasma due to not desulfuration to urea group.
IN VIVO METABOLISM OF SOME THIOUREAS COMPOUNDS FROM 4- AMINO-3,5 – DIMETHYL PYRAZOLE Thiourea derivatives have attracted attention during the last decades due to their significant biological activities as antitubercular, antibacterial, antifungal, anti-HIV-I, antihypertensive as well as good anticonvulsant properties. However among numerous studies, there are very few concerning the metabolism of thioureas. We therefore investigated the in vivo metabolism of N-phenyl-N'-(3,5-dimethylpyrazole-4-yl)thiourea as potent anticonvulsant. In this investigation, the previous results had showed that the substrate was metabolized largely unchanged in the plasma. Only two unknown metabolites were determined with low concentration. So we choosed the bearing substituted phenyl ring at thiourea compounds and in vivo metabolism pathway was studied in details in this study. Substrates, N-(4-fluoro/ chlorophenyl)-N'-(1,3,5-trimethylpyrazole-4-yl)thioureas (T2 and T3), and their possible metabolites were synthesized and the structures of the compounds were elucidated by spectral and elemental analysis. Substrates were dissolved in 5% gum arabica and administered intraperitoneally at 100 mg/ kg doses in approximately 0.1 ml volume. Blood samples were withdrawn before and 30 min, 1., 2., 4., 8., 12. and 24. h after dosing. Chromatographic separation of substrate and its metabolites were performed using a Hichrom chromasil C18 column (150 mm x 4.6 mm i.d., 5μm particle size), made of stainless steel. The optimal composition of the mobil phase was achieved by different mixtures of pure methanol and water. From the biotransformation of these thiourea compounds, N-dealkylation metabolites N-(4-fluoro/ chlorophenyl)-N'-(3,5-dimethylpyrazole-4-yl)thioureas (T1 and T4) were identified together with unchanged substrate (T2 and T3) in plasma by comparing their to reference standards by HPLC-UV/ DAD. Furthermore the desulfuration metabolites were not determined in plasma samples. These results proved that pharmacological active of thiourea functional group was unchanged in plasma due to not desulfuration to urea group.