Investigation of vitamin B6 derivatives by one- and two-dimensional NMR techniques

U sklopu ovog istraživanja sintetizirani su novi spojevi derivata vitamina B6 i to piridoksina s aminokiselinama (alanin i fenilalanin), te neutralnog piridoksala s primarnim aminom (2-amin-4-klorfenol) u molarnom omjeru 1 : 1. Amino skupina alanina zaštićena je s tert-butiloksikarbonilnom skupinom (Boc), a fenilalanina s karboksibenzil zaštitnom skupinom (Z). Oba aminokiselinska estera dobivena su reakcijom aminokiselina s dicikloheksilkarbodiimidom (DCC) i α4,α5-izobutiliden piridoksinom. Schiffova baza prethodno neutraliziranog piridoksal hidroklorida dobivena je njegovom reakcijom s 2-amin-4-klorfenolom. Dobiveni spojevi okarakterizirani su 1D i 2D spektroskopijom NMR u otopini, spektrometrijom masa (ESI-MS) te spektroskopijom IR zračenja u čvrstom stanju. Od 1D tehnika NMR korištene su 1H i 13C APT, a od 2D 1H—1H COSY, 1H—1H NOESY, 1H—13C HMQC, 1H—13C HMBC i 1H—15N HMBC.Three compounds of vitamine B6 derivatives were prepared by reaction of pyridoxine with amino acids (alanine and phenylalanine), and by reaction of neutral pyridoxal and primary amine (2-amino-4-chlorophenol). As N(alpha)-amino protecting group, tert-butoxycarbonyl (Boc-Ala) and carboxybenzyl group (Z-Phe) were used. Both aminoacids esters were prepared by reaction of aminoacids with N,N'-dicyclohexylcarbodiimide (DCC) and α4,α5- isobutylidene pyridoxine. Schiff's base was synthesized by reaction of neutral pyridoxal and 2-amino-4-chlorophenol. All synthesized compounds were identified by NMR spectroscopy in solution and mass spectrometry. Used one-dimensional NMR techniques were 1H and 13C APT, while the two-dimensional used techniques were 1H—1H COSY, 1H—1H NOESY, 1H—13C HMQC, 1H—13C HMBC and 1H—15N HMBC. In solid state the compounds were characterized by IR spectroscopy