Glucosinolate profile of white wall rocket (Diplotaxis erucoides). Conventional vs. microwave assisted isolation of volatiles : bachelor thesis

Glukozinolati su sekundarni metaboliti koji su zastupljeni u 16 botaniĉkih porodica reda Capparales, a najznaĉajnija je porodica Brassicaceae u koju se ubrajaju dobro poznate biljke iz svakodnevne prehrane kao što su kupus, brokula, cvjetaĉa, prokulice, rotkvica, repa, gorušica i druge. Po kemijskoj strukturi to su β-tioglukozidni-N-hidroksisulfati s varijabilnim boĉnim lancem. Glukozinolati su kemijski i biološki neaktivni. Njihovom enzimskom, kemijskom ili termiĉkom razgradnjom nastaje niz biološki aktivnih produkata od kojih su najviše istaţivani izotiocijanati. U ovom radu primjenjene su razliĉite metode izolacije ukljuĉujući hidrodestilaciju, autolizu te mikrovalnu destilaciju i ekstrakciju kako bi se istraţila termiĉka, enzimska i mikrovalovima potpomognuta razgradnja glukozinolata. Posebno je zanimljiva mikrovalna ekstrakcija jer predstavlja pravi primjer uporaba zelene tehnologije. Cilj ovoga rada bio je izolirati i identificirati hlapljive sumporove spojeve iz dvoredca (Diplotaxis erucoides). Biljni materijal sakupljen je u Splitu u travnju 2019. Izolacija hlapljivih spojeva provedena je hidrodestilacijom po Clevengeru, autolizom te mikrovalnom destilacijom i ekstrakcijom bez dodatka otapala. Za identifikaciju izoliranih hlapljivih spojeva korištena je GC-MS tehnika. U listu i komuški dvoredca preko razgradnog produkta alil-izotiocijanata identificiran je sinigrin, dok je u korijenu, cvijetu i stabljici identificiran sinigrin preko alil-izotiocijanata te glukonasturcin preko 2-feniletil-izotiocijanata. HPLC-DAD tehnikom preko desulfoglukozinolata potvrĊeno je njihovo prisustvo te su navedeni spojevi i kvantizirani. Koncentracija sinigrina u listu bila je 12,0996 μmol/g, u stabljici 10,4135 μmol/g, u komuški 28,8295 μmol/g, u korijenu 2,6966 μmol/g i u cvijetu je 16,3358 μmol/g. Koncentracija glukonasturcina u stabljici bila je 0,7765 μmol/g, u korijenu 16,4398 μmol/g i u cvijetu je 0,2485 μmol/g.Glucosinolates are secondary metabolites present in 16 botanical families of the Capparales order, among which the most important is Brassicaceae family, which includes well-known plants of everyday nutrition such as cabbage, broccoli, cauliflower, broomsticks, radis, beets and others. Chemically these are β-thioglucoside-N-hydroxysulfates with a variable side chain. Glucosinolates are chemically and biologically inactive. Their enzymatic, chemical, and thermal degradation result in formation of series of biologically active products, among which the most studied ones are isothiocyanates. In our study, we used different methods including hydrodistillation, autolysis followed by extraction, and microwave assisted distillation and extraction in order to investigate thermal, enzymatic, and microwave-assisted decomposition of glucosinolates. Microwave extraction is particularly interesting because it represents a true example of green technology. The aim of this study was to isolate and identify volatile sulfur compounds from white wall rocket (Diplotaxis erucoides). Plant material was collected in Split in April 2019.The isolation of volatile compounds was performed by hydrodistillation in Clevenger type apparatus, autolysis and microwave distillation and extraction without solvent addition. GC-MS technique was used to identify the isolated volatiles. The leaf and siliquae volatile extractscontained allyl-isothiocyanate, the breakdown product ofsinigrin, while the root, flower and stem next to allyl-isothiocyanate also contained 2-phenylethyl- isothiocyanate, which originated from gluconasturtiin. Glucosinolates were also confirmed and quanified by HPLC-DAD technique. Leaf contained 12,0996 μmol/g of sinigrin, stem 10,4135 μmol/g, siliquae 28,8295 μmol/g, root 2,6966 μmol/g and flower 16,3358 μmol/g. Gluconasturtiin concentration in stem was 0,7765 μmol/g, in root 16,4398 μmol/g and in flower 0,2485 μmol/g