Eksperimentalni i teorijski opis vitamina C

master's thesis

• Title (english): Experimental and theoretical description of the vitamin C
• Author: Ema Podravski
• Mentor: Vladimir Dananić (mentor)
• Committee member: Vladimir Dananić (predsjednik povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Committee member: Vesna Ocelić Bulatović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-02-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Cilj ovog rada je pregled teorije vitamina C te izrada infracrvenog spektra za pet različitih uzoraka koji sadrže vitamin C. Prikazana su strukturna, fizikalna i kemijska svojstva ovog vitamina. Sprječava bolest skorbut pa se naziva askorbinska kiselina. Vitamin je L-enantiomer molekule. Gotovo je planarni peteročlani laktonski prsten s postraničnim lancem. Ima mogućnost reverzibilne oksidacije do dehidroaskorbinske kiseline i stvaranja relativno stabilnih slobodnih radikala te može djelovati kao sakupljač slobodnih radikala u reakcijama koje uključuju reaktivne oksidacijske vrste (ROS). Nasuprot tome, u nekim slučajevima može djelovati i prooksidativno. Albert Szent-Györgyi je 1928. godine izolirao molekulu vitamina C, a stvarnu strukturu je 1933. godine razradio Norman Haworth, nakon čega je Tadeus Reichstein objavio i patentirao komercijalno izvedivu metodu sinteze iz glukoze. Navedene su brojne funkcije i važnost kod biljaka, životinja i ljudi. Sudjeluje u zaštiti drugih antioksidansa, pomaže tijelu da apsorbira željezo, može inaktivirati i neutralizirati histamin te ima ulogu u imunološkom sustavu. Povezuje se sa zaštitom lipida, DNK i proteina od oksidansa te djeluje u mnogim mono- i dioksigenazama za održavanje metala u reduciranom stanju. Neophodan je za ispravno odvijanje fotosinteze te može kontrolirati diobu, produljenje i diferencijaciju stanica, kao i programiranu staničnu smrt. Navedene su količine vitamina C u prehrambenim izvorima te dnevne potrebe kod ljudi za sve uzraste. Kod većih doza ne dolazi do potpune apsorpcije, a velik dio apsorbirane doze se ne metabolizira i izlučuje urinom. Glavni metaboliti askorbinske kiseline u organizmu su dehidroaskorbinska kiselina, 2,3-diketo-gulonska kiselina i oksalna kiselina. Dostupne su brojne analitičke metode za opis vitamina C od kojih je u ovom radu korištena infracrvena spektroskopija s Fourierovom transformacijom. Vitamin C ima mnoge primjene u medicini te prehrambenoj, kemijskoj i kozmetičkoj industriji.

Abstract (english)

The aim of this paper is to review the theory of vitamin C and to create an infrared spectrum for five different samples containing vitamin C. The structural, physical and chemical properties of this vitamin are presented. It prevents the disease scurvy, which is why it got the name ascorbic acid. Vitamin is the L-enantiomer of the molecule. It is an almost planar five-membered lactone ring with a side chain. In addition to the possibility of reversible oxidation to dehydroascorbic acid, it can form relatively stable free radicals and can act as a scavenger of free radicals in reactions involving reactive oxidizing species (ROS). On the other hand, in some cases it can also act as a pro-oxidant. Albert Szent-Györgyi isolated the vitamin C molecule in 1928, and the actual structure was worked out by Norman Haworth in 1933, after which Tadeus Reichstein published and patented a commercially viable method of synthesis from glucose. Numerous functions and importance in plants, animals and humans are listed. It participates in the protection of other antioxidants, helps the body to absorb iron, can inactivate and neutralize histamine and plays a role in the immune system. Further, it is associated with the protection of lipids, DNA and proteins from oxidants and acts in many mono- and dioxygenases to maintain metals in a reduced state. It is necessary for the proper development of photosynthesis and can control the division, elongation and differentiation of cells, as well as programmed cell death. Amounts of vitamin C in food sources and daily requirements for people of all ages are listed. With larger doses, complete absorption does not occur, and a large part of the absorbed dose is not metabolized and is excreted in the urine. The main metabolites of ascorbic acid in the body are dehydroascorbic acid, 2,3-diketo-gulonic acid and oxalic acid. Numerous analytical methods are available for the description of vitamin C, of which infrared spectroscopy with Fourier transformation was used in this work. Vitamin C has many applications in medicine as well as in the food, chemical and cosmetic industries.

• Keywords: vitamin C; askorbinska kiselina; askorbat; dehidroaskorbinska kiselina
• Keywords (english): vitamin C; ascorbic acid; ascorbate; dehydroascorbic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:149:314638
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-10 12:32:58