Allium neapolitanum Cirillo: impact of the autolysis on chemical composition of sulfur compounds obtained by hydrodistillation : bachelor thesis

Abstract

Allium neapolitanum Cirillo (lat. Allium- češnjak, neapolitanum- napuljski) je višegodišnja biljka iz roda Allium, koji se sastoji od mnogo različitih vrsta. Ovu vrstu karakterizira specifičan okus, miris, lakrimacija (suzenje očiju) te farmakološka svojstva koja potječu od prisutnih hlapljivih sumporovih spojeva nastalih enzimskom hidrolizom nehlapljivih S-alk(en)il cistein sulfoksida. Eterično ulje dobiveno je iz različitih dijelova biljke (cvijet, list i stabljika, lukovica) destilacijom u aparaturi po Clevengeru. Pri tome je jedan uzorak destiliran bez autolize, dok je drugi prethodno autoliziran u vremenu od 48h. Destilacijom dobivena eterična ulja analizirana su plinskom kromatografijom- masenom spektrometrijom (GC-MS). Analizom je utvrđeno da svi uzorci u sebi sadrže hlapljive sumporove spojeve kao što su dimetil trisulfid, (metilsulfanil)metil disulfid i dimetil tetrasulfid. Također je utvrđeno da uzorak koji je prvo autoliziran pa potom destiliraliran sadrži značajno veću koncentraciju navedenih sumporovih spojeva. Iz toga je vidljivo da autoliza ima važan utjecaj na koncentraciju sumporovih spojeva zbog dužeg kontakta egzogenih enzima i S-alk(en)il cistein sulfoksida.Allium neapolitanum Cirillo (lat. Allium-garlic, neapolitanum-from Naples) is a perennial plant of the genus Allium, which has many different species. This one has a special taste, smell, lacrimation (eye tear), but also has the pharmacological characteristics which comes from volatile sulfur compounds formed by enzymatic hydrolysis of non-volatile S-alk(en)yl cysteine sulphoxide. Essential oil was obtained from different plant parts (flower, leaf and stem, and bulb) by distillation in Clevenger apparatus in two ways: direct distillation, and after the autolysis of the plant material for 48 hours before the distillation. The obtained essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS).The analysis showed that all the samples contain volatile sulfur compounds such as: dimethyl trisulfide, (methylsulfanyl)methyl disulfide and dimethyl tetrasulfide. Also, it was determined that 48 hour autolysed plant material contained significantly more volatile sulfur compounds. It was concluded that the autolysis has important impact on the concentracion of the sulfur compounds due to the longer contact with egzogenous enzymes with S-alk(en)il cysteine sulphoxide