Determination of glucosinolates in Biscutella laevigata and Eruca vesicaria and their isolation using accelerated solvent extraction : diploma thesis

Abstract

U ovom radu određen je glukozinolatni profil sjemena rokule (Eruca vesicaria) i odabranih biljnih dijelova biokovske i poljske glatke dvoštitke (Biscutella laevigata) izravnom UHPLC-DAD-MS/MS analizom preko odgovarajućih desulfoglukozinolata. Ekstrakcija glukozinolata provedena je sukladno modificiranoj ISO 9167-1 metodi. Dodatno, glukozinolati sjemena rokule izolirani su metodom ubrzane ekstrakcije otapalom pri povišenom tlaku (ASE) s ciljem kvalitativne i kvantitativne usporedbe dobivenih glukozinolata s ISO metodom. Ispitana je ekstrakcijska učinkovitost ASE na temperaturama od 50 ºC, 70 ºC i 90 ºC i s ulaznim količinama biljnog materijala od 1 g i 100 mg. Analizom sjemena rokule, neovisno o primijenjenoj metodi izolacije, dokazana je prisutnost glukoerucina u najvišim koncentracijama (6,13-90,24 μmol/g suhog biljnog materijala). U dosta nižem sadržaju pronađeni su glukorafanin (0,14-1,46 μmol/g) i glukosinalbin (0,13-0,65 μmol/g), a ostali glukozinolati su prisutni u tragovima. Pojedinačni i ukupni (92,35 μmol/g) sadržaji glukozinolata pokazali su se značajno višim primjenom ISO 9167-1 metode. Najveći sadržaj glukozinolata za ASE dobiven je pri temperaturi 70 ºC, tj. 32,57 μmol/g za 1 g i 7,80 μmol/g za 100 mg. Glukohirsutin i glukobrasicin su pronađeni u svim biljnim dijelovima biokovske glatke dvoštitke, a najveći sadržaj bio je u komuški (43,57 μmol/g za glukohirsutin i 14,08 μmol/g za glukobrasicin). Općenito, komuška se pokazala najbogatijom glukozinolatima (57,85 μmol/g), a najsiromašnija je bila stabljika (6,49 μmol/g). Analizom poljske glatke dvoštitke, glukozinolati su ustanovljeni samo u sjemenu unutar kojeg je najsadržajniji bio glukohirsutin (30,51 μmol/g), dok uzorak dobiven in vitro nije sadržavao glukozinolate.In this paper, the glucosinolate profile of rocket seeds (Eruca vesicaria) and selected plant parts of Biokovo and Polish buckler mustard (Biscutella laevigata) was determined using UHPLC-DAD-MS/MS analysis by their desulfo-counterparts. Glucosinolate extraction was performed according to the modified ISO 9167-1 method. Additionally, the glucosinolates of rocket seeds were isolated by accelerated solvent extraction at elevated pressure (ASE) with the aim of comparing the qualitative and quantitative glucosinolate profile with the ISO method. The extraction efficiency of ASE was tested at temperatures of 50 ºC, 70 ºC and 90 ºC with the amounts of plant material of 1 g and 100 mg. The analysis of rocket seeds, regardless of the applied isolation method, revealed the presence of glucoerucin having the highest content (6.13-90.24 μmol/g of dried plant material). Glucoraphanin (0.14- 1.46 μmol/g) and glucosinalbin (0.13-0.65 μmol/g) were found in much lower concentrations, and other glucosinolates were present in traces. Individual and total (92.35 μmol/g) glucosinolate contents were shown to be significantly higher using the ISO 9167-1 method. The highest yield for ASE was obtained at 70 ºC with total glucosinolate content of 32.57 μmol/g for 1 g and 7.80 μmol/g for 100 mg. Glucohirsutin and glucobrassicin were found in all plant parts of buckler mustard from Biokovo and the highest contents were found in siliquae (43.57 μmol/g for glucohirsutin and 14.08 μmol/g for glucobrassicin). In general, siliquae proved to be the richest in glucosinolates (57.85 μmol/g), while the stem had the lowest (6.49 μmol/g). By analyzing the Polish buckler mustard, glucosinolates were found only in the seeds, the most abundant of which was glucohirsutin (30.51 μmol/g), while the glucosinolates were absent in the plant sample obtained in vitro