Sinteza hlapnih derivatov kafre in mentola ter olfaktorno vrednotenje

Bohnec, Klara (avtor), Obreza, Aleš (mentor)

Mentol je ciklični monoterpenski alkohol, ki je pomembna sestavina več kot 100 eteričnih olj. Najbolj znana je njegova prisotnost v raznih vrstah iz rodu Meta (Mentha). Mentol najpogosteje pridobivamo iz eteričnega olja poprove mete s parno destilacijo. Pri standardnih pogojih je trden, v obliki belih ali brezbarvnih kristalov. Kafrovec spada v družino lovorovk (Lauraceae) in je pogost v vzhodni in južni Aziji. Je eden izmed najpomembnejših naravnih virov kafre. Kafra nastaja v celicah, ki so porazdeljene po celotnem drevesu. Naravno kafro pridobivajo s parno destilacijo lesa kafrovca, ki ji sledi čiščenje, najpogosteje s kristalizacijo ali sublimacijo. Pojavlja se v obliki brezbarvnih ali belih kristalov z močnim, značilnim vonjem. Namen naše diplomske naloge je bil preveriti vpliv manjših sprememb v strukturah kafre in mentola na vonj produktov kemijskih reakcij. V eksperimentalnem delu naloge smo najprej uspešno reducirali kafro. Nato smo z uporabo klasičnih metod organske kemije izvedli šest kemijskih reakcij, katerih produkti so bili hlapni derivati reducirane kafre ali mentola. Kolonsko adsorpcijsko kromatografijo smo uporabili za izolacijo in čiščenje produktov. Uspešnost reakcij in identiteto produktov smo potrdili z uporabo instrumentalnih analiznih metod, v našem primeru z jedrsko magnetno resonanco in infrardečo spektroskopijo. Masnih spektrov z obstoječimi napravami na Katedri za farmacevtsko kemijo, Fakultete za farmacijo, zaradi slabe ionizacije produktov nismo uporabili. Z vonjalno analizo smo ovrednotili mentol, kafro, reducirano kafro in dva produkta naših sintez. Preizkuševalci so morali oceniti prijetnost in jakost vzorcev. Na koncu pa so morali v tabelo vpisati še asociacije, ki so se jim porodile pri posameznih vzorcih. Večina testirancev je ocenila njihov vonj kot prijeten. Kot najintenzivnejši vonj so anketiranci ocenili vonj mentola. Izdelali smo tudi preprost poltrdni kozmetični izdelek, in sicer hidrogel, ki je vseboval kafro in mentol. Ob nanosu na kožo se je pojavil hladilni občutek. Čez nekaj tednov smo zaznali razrast mikroorganizmov zaradi pomanjkanja konzervansa in posledično slabe protimikrobne zaščite.

• Jezik: Slovenski jezik
• Ključne besede: kafra, mentol, kromatografske metode, sinteza, vonjalna analiza
• Vrsta gradiva: Diplomsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2020
• PID: 20.500.12556/RUL-119232
• Datum objave v RUL: 05.09.2020

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Synthesis of volatile derivatives of camphor and menthol and olfactory evaluation

Izvleček

Menthol is a cyclic monoterpene alcohol which is an important ingredient in more than 100 essential oils. Its presence is best known in various plants that belong to the mint genus (Mentha). Menthol is obtained primarily from essential peppermint oil by steam distillation. At room temperature it is solid and in the form of white or colorless crystals. Camphor tree belongs to the laurel family (Lauraceae) and it is widespread in East and South Asia. It is one of the most important natural sources of camphor. Camphor is formed in cells that are distributed throughout the entire tree. Natural camphor is obtained by steam distillation of camphor wood, followed by crystallization or sublimation. It appears in the form of colorless or white crystals with a strong and distinctive smell. The aim of our thesis was to test the effect of minor changes in structures of menthol and camphor on the smell of products of chemical reactions. In the experimental part, we first successfully reduced camphor. Then using classical methods of organic chemistry, we performed six syntheses, the products of which were volatile derivatives of reduced camphor or menthol. Column adsorption chromatography was used to isolate and purify our desired products. The success of the reactions and the identity of the products were verified by using instrumental methods of analysis, in our case nuclear magnetic resonance spectroscopy and infrared spectroscopy. We did not use the mass spectrometry devices at The Chair of Pharmaceutical Chemistry at the Faculty of Pharmacy due to poor ionization of the products. By odor analysis we have made olfactory evaluation of menthol, camphor, reduced camphor and two of our synthesis products. The respondents had to evaluate the pleasantness and strength of the samples. Finally, they had to write down the associations that came to their mind for all individual samples. Most of the test subjects rated their smell as pleasant. Respondents rated the smell of menthol as the most intense. In addition, we formed a hydrogel which is a simple semi-solid cosmetic product. It contained camphor and menthol. When applied to the skin, a cooling sensation appeared. After a few weeks, we detected an overgrowth of microorganisms due to lack of preservative and consequent poor antimicrobial protection.

• Ključne besede: camphor, menthol, chromatography methods, synthesis, odor analysis