Pėdų grybelis (lot. Tinea pedis) – tai dermatofitų Trichophyton rubrum, Trichophyton mentagrophytes ir Epidermophyton floccosum sukeltas lėtinis pėdų, kojų tarpupirščių pažeidimas, pasireiškiantis odos įtrūkimais, pleiskanojimu, nemaloniu kvapu ir niežuliu. Vaistinio čiobrelio (lot. Thymus vulgaris L.) eterinis aliejus, savyje turintis timolio (36 – 55 proc.), gali apsaugoti pėdas nuo grybelio atsiradimo. Čiobrelių eterinį aliejų patogu įvesti į aliejinę terpę, tačiau aliejinius tirpalus naudoti nėra patogu. Todėl šio darbo tikslas pagaminti lipofilinį gelį, skirtą pėdų grybelio prevencijai. Šis tyrimas apima: 1) timolio kiekio nustatymą čiobrelių eteriniame aliejuje; 2) optimalaus aliejaus ir gelifikuojančios medžiagos santykio parinkimą; 3) pagaminto lipofilinio gelio su čiobrelių eteriniu aliejumi klampos, pH reikšmės ir išvaizdos įvertinimą; 4) oleogelio veiksmingumo nustatymą, atliekant mikrobiologinį tyrimą. Rezultatai: ESC būdu nustatyta, kad čiobrelių eteriniame aliejuje timolio yra 41,06±0,03 proc. Oleogelio pagrindu nuspręsta naudoti alyvuogių aliejų, nes skystojo parafino ir alyvuogių aliejaus mišinys nesudarė stabilios gelinės struktūros. Pagaminti oleogeliai visą stebėjimo laiką (6 mėn.) išlaikė savo išvaizdą – vientisą struktūrą, skaidrumą, šviesiai geltoną spalvą, čiobrelių kvapą ir pusiau kietą konsistenciją. Atlikus pH reikšmės stebėjimus nustatyta, kad oleogelių pH reikšmė reikšmingai nekito ir išliko atitinkanti žmogaus fiziologinę odos pH reikšmę... [toliau žr. visą tekstą] / Foot fungus (lat. Tinea pedis) is a skin disease caused by dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum. The symptoms are cracks, itch, dandruff and unpleasant odor of the feet skin. Thyme (lat. Thymus vulgaris L.) essential oil containing of 36 – 55 percent of thymol can protect feet from fungus. Thyme essential oil is convenient to introduce in oil medium, but oil solutions are uncomfortable to use. Therefore, the aim of this work is to produce a lipophilic gel for prevention of foot fungus. This study includes the following: 1) determining the amount of thymol in the thyme essential oil; 2) determination of the optimal ratio of oil and gelling agent material; 3) pH value and appearance evaluation of the produced lipophilic gel with thyme essential oil viscosity; 4) the effectiveness of the lipophilic gel in microbiological research. The results: using HPLC method it has been found out that thyme essential oil contains 41.06±0.03 percent thymol. It was decided to use olive oil on oleogel basis because liquid paraffin and olive oil mixture didn’t make stable gel structure. Produced oleogels kept the same appearance features for all observation time (6 months) such as homogenous structure, clearness, light yellow color, the smell of thyme and semi – solid consistency. During the measurement of pH values of oleogels, it has been found out that pH values matched human physiological pH value. During the measurement of viscosity of... [to full text]

<p><strong>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</strong></p><p>Ispitana je ekstrakcija timijana (<em>Thymus vulgaris L.</em>) primenom ugljendioksida u superkritičnom stanju kao ekstragensa. Razrađen je postupak tečne hromatografije pod visokim pritiskom (HPLC) za određivanje farmakolo&scaron;ki aktivnih fenolnih jedinjenja, timola i karvakrola, koji obezbeđuje visok stepen reproduktivnosti određivanja (za timol K_w = 1,29%). Za kvalitativnu i kvantitativnu analizu proizvoda na bazi timijana, etarskog ulja i ekstrakata, primenjen je metod gasne hromatografije (GC) sa masenom spektrometrijom (MS). Sadržaj etarskog ulja određen oficinalnim postupkom koji propisuje jugoslovenska farmakopeja iznosi 1,75% (V/m). Dominantna komponenta etarskog ulja timijana je timol čiji je sadržaj 50,06% (m/m), dok je karvakrol prisutan, praktično, u tragovima (1,15%). Od prisutnih parafina u etarskom ulju, največi sadržaj ima n-tetradekan (16,11%). U totalnom ekstraktu timijana dobijenom metilen- hloridom primenom ekstrakcije sa povremenim ispu&scaron;tanjem ekstrakta (Ekstrakcija po Soxhlet-u), koji je dobijen u prinosu 4,95% (m/m), dominantna komponenta je n-tetradekan (47,18%), dok je sadržaj timola 16,11%.<br />Kinetika ekstrakcije timola se može uspe&scaron;no predstaviti analogno izrazu za kinetiku reakcije prvog reda, primenom koje se dobija največa vrednost konstante brzine ekstrakcije (k) 0,2209 h^-1 za selektovani protok superkritičnog ugijendioksida 97,725 dm³/h.<br />Primenom timijana stepena usitnjenosti d₂ srednjeg prečnika 0,35 mm za ekstrakciju superkritičnim ugijendioksidom (100 bar; 40&deg;C; 2,5 sata) postiže se kvantitativna ekstrakcije prisutnog etarskog ulja. Po svom sastavu ovaj ekstrakt je najsličniji etarskom ulju timijana dobijenom destliacijom pomoću vodene pare. Produžavanje vremena ekstrakcije iznad 2,5 sata ima za posledicu povećani prinos, pre svega, parafina.<br />Primenom ugljendioksida male moći rastvaranja (80 bar; 40⁰C;&nbsp; d=0,1918 g/cm³) ne postiže se kvantitativna ekstrakcija etarskog ulja. Povećavanjem radnog pritiska od 100 do 400 bar, usled povećanja moći rastvaranja, dobijaju se ekstrakti koji su po svom sastavu sve sličniji totalnom ekstraktu dobijenom ekstrakcijom metilenhloridom.<br />Za modelovanje ekstrakcionog sistema timijan - superkritični ugljendioksid je primenjena jednačina Reverchon-a i Sesti Osseo-a:<br />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Y = 100 [1-exp(-t/t_i)]<br />gde je: Y - normalizovani ekstrakcioni prinos (%); t - vreme ekstrakcije (s) i t_i -&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; vreme unutra&scaron;nje difuzije (s)<br />odnosno njen modifikovani oblik:<br />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Y = 100 [1 - ehr (at + b)]<br />Izračunate vrednosti standardne gre&scaron;ke regresije (S_Y,X) ukazuju da u osnovi modifikovana jednačina bolje fituje normalizovane prinose kako totalnog ekstrakta, tako i timola, u odnosu na polaznu jednačinu.<br />Jednačine:<br />&nbsp;&nbsp; log S = a m_rel + b<br />i<br />&nbsp;&nbsp; log S = a <em>d</em>_C02 + b<br />gde je: S - rastvorljivost totalnog ekstrakta (g/dm³), odnosno timola (mg/dm ) u ugljendioksidu; m_rel - relativna masa ugljendioksida (g CO2/g timijana) i <em>d</em>_CO2 zapreminska masa ugljendioksida (g/cm³)<br />se mogu, takođe, uspe&scaron;no primeniti za modelovanje ekstrakcije ispitivanog sistema.<br />Primenom ugljendioksida u tečnom stanju (65 bar; 23&deg;C) se dobija ekstrakt timijana sličan po svom sastavu ekstraktu dobijenom ekstrakcijom superkritičnim ekstragensom na pritisku 100 bar.<br />U cilju dobijanja ekstrakta timijana koji je po svom kvalitativnom i kvantitativnom sastavu najsličniji etarskom ulju dobijenom oficinalnim postupkom destilacije pomoću vodene pare, neophodno je za ekstrakciju koristiti ugljendioksid zapreminske mase 0,6302 g/cm³( 100 bar;40&deg;C), biljni materijal stepena usitnjenosti d₂, vreme ekstrakcije 2,5 sata i protok ekstragensa 97,725 dm³/h.</p> / <p><strong>Abstract was processed by technology for Optical character recognition (OCR).</strong></p><p>The extraction of thyme (Thymus vulgaris L.) by supercritical carbon dioxide as an extragent was investigated. The developed HPLC (High Pressure Liquid Chromatography) method for determination of pharmacologically active phenolic compounds, thymol and carvacrol, showed a high reproducibility (Kw for thymol 1.29%). Qualitative and quantitative analyses of thyme products, essential oil and extracts, were carried out by gas chromatography - mass spectrometry (GC-MS). The content of essential oil determined by an official procedure given by Yugoslav pharmacopoeia was 1.75% (V/w). The predominant compound of the essential oil is thymol (50.06%; w/w), while carvacrol is present, practically, in traces (1.15%; w/w). The content of n-tetradecane in the thyme essential oil (16.11%; w/w) is higher than that of other paraffins. In the total thyme extract obtained by methylene chloride using extraction with periodical exchange of the extract (Soxhlet extraction) in a yield of 4.95%(w/w), the predominant compound was n-tetradecane (47.18%), while the content of thymol was 16.11%.</p><p>The extraction kinetic of thymol can be successfully expressed by analogy to first order reaction kinetic, and a highest value of extraction rate constant (k) of 0.2209 h-1 for the selected flow rate of supercritical carbon dioxide of 97.725 dm3/h.<br />A quantitative extraction of thyme essential oil by supercritical carbon dioxide (100 bar; 40&deg;C; 2.5hours) was obtained using thyme of the grinding degree d2 (mean particle diameter 0.35 mm). The composition of this extract is very similar to that of the essential oil obtained by steam distillation. A higher yield of extraction, primarily of paraffins, was obtained by prolonging the extraction time over 2.5 hours. The use of carbon dioxide of low solubility power (80 bar; 400C; d =0.1918 g/cm3) did not yield a quantitative extraction of thyme essential oil.<br />Ву increasing extraction pressure from 100 to 400 bar, i.e. solubility power, the extract composition was more and more similar to the composition of total extract obtained by methylene chloride.<br />То model extraction of the system thyme - supercritical carbon dioxide use was made of the Reverchon - Sesti Osseo equation:</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Y = 100 [1-exp(-t/ti)]</p><p>where: Y - normalized extraction yield (%); t - extraction time (s) and ti - internal diffusion time (s)<br />i.e. of its modified form:<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Y = 100 [1 - ехр (at + b)]<br />The calculated values of standard error of regression (SY,X) show that the modified equation is generally a better fit for the normalized yields of total extract and thymol compared to the original equation.<br />Equations:</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; log S = a mrel + b<br />and<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; log S = a dC02 + b<br />where: S - solubility of total extract (g/dm3), i.e. of thymol (mg/dm3) in carbon dioxide; mrel - relative mass of carbon dioxide (g CO2/g thyme) and dCO2 carbon dioxide density (g/cm3)</p><p>could be successfully used for modelling of the investigated extraction system.<br />The composition of thyme extract obtained by liquid carbon dioxide (65 bar; 23&deg;C ) is very similar to that obtained by supercritical extragent at a pressure of 100 bar.<br />То obtain a thyme extract whose qualitative and quantitative characteristics are most similar to those of the essential oil obtained using official procedure by steam distillation, it is necessary to use a carbon dioxide density of 0.6302 g/cm3 (100 bar; 400C), grinding degree of thyme d2, extraction time of 2.5 hours and extragent flow rate of 97.725 dm3/h.</p>