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Metil salicilat ali metil 2-hidroksibenzoat je ester, rastlinskega izvora. Po videzu je pri sobni temperaturi bistra brezbarvna tekočina. Zaradi svojega močnega vonja se uporablja v dekorativni kozmetiki, šamponih, toaletnih milih, čistilih ali kot aroma za živila. Dokazano je tudi njegovo protibakterijsko, analgetično in protivnetno delovanje, zato se pogosto uporablja kot lokalna protivnetna ali analgetična učinkovina. Predstavlja glavno sestavino aromatične rastline zelenke (Gaultheria procumbens), iz listov katere pridobivamo eterično olje. Gre za eno bolj nevarnih eteričnih olj, saj se hitro absorbira iz prebavnega trakta in skozi kožo. Draži lahko oči, sluznice, zgornje dihalne poti in kožo, ob zaužitju pa je lahko celo smrtonosno. Vedno bolj priljubljeno postaja sintezno pridobivanje metil salicilata iz salicilne kisline. Namen diplomskega dela je bil sintetizirati derivate metil salicilata in končne produkte olfaktorno vrednotiti s pomočjo prostovoljcev. Želeli smo dobiti čim več hlapnih nizkomolekularnih derivatov s prijetnim vonjem, ki bi jih lahko uporabljali v kozmetični industriji. Reakcije estrenja in etrenja so potekale na prosti fenolni -OH skupini metil salicilata. Uspelo nam je sintetizirati štiri estre in tri etre, njihovo identiteto pa smo potrdili z instrumentalnima metodama: jedrsko magnetno resonanco in infrardečo spektroskopijo. Nastalim derivatom so nato prostovoljci določali prijetnost in jakost vonjev ter navedli tudi asociacije na druge vonje. Večini vzorcev so pripisali prijeten vonj in šibko ali srednje močno jakost. Za najprijetnejše so se izkazali 2-acetoksibenzoat, metil 2-(propioniloksi)benzoat in metil 2-izopropoksibenzoat. S pomočjo rezultatov te analize smo ugotovili, da ima sprememba kemijske strukture močan vpliv na prijetnost in jakost vonja. Methyl salicylate or methyl 2-hydroxybenzoate is an ester of plant origin. It looks like a clear, colorless liquid at room temperature. Due to its strong smell, it is used in decorative cosmetics, shampoos, toilet soaps, cleaning products or as a food flavoring. Its antibacterial, analgesic and anti-inflammatory effects have also been proven, so it is often used as a local anti-inflammatory or analgesic agent. It is the main component of the aromatic wintergreen plant. Essential oil is obtained from its leaves. It is one of the more dangerous essential oils, as it is quickly absorbed by the digestive system and through the skin. It may irritate the eyes, mucous membranes, upper respiratory tract and skin and can even be fatal if swallowed. Synthetic production of methyl salicylate from salicylic acid is becoming increasingly popular. The aim of the thesis was to synthesize methyl salicylate derivatives and evaluate the final products in an olfactory test with the help of volunteers. We strived to obtain as many volatile low-molecular derivatives with a pleasant smell as possible, which could be used in the cosmetics industry. Esterification and etherification reactions occurred on the free phenolic -OH group of methyl salicylate. We managed to synthesize four esters and three ethers and confirmed their identity by instrumental methods: nuclear magnetic resonance and infrared spectroscopy. The volunteers then determined how pleasant and strong each odor of the resulting derivates was. They also indicated associations with other odors. Most samples were attributed to a pleasant smell and a weak or medium strength. 2-acetoxybenzoate, methyl 2-(propionyloxy)benzoate and methyl 2-isopropoxybenzoate proved the most pleasant. The results of this analysis led us to discover that the change in chemical structure strongly influences the pleasantness and strength of the smell. |
