Dalmatian sage (
Salvia officinalis
L.) is a Croatian medicinal herb with important biological and pharmacological properties due to diverse polyphenolic composition. Therefore, this study aimed at ...evaluating the effects of three solvents (30 % ethanol/water,
v
/
v
; 30 % acetone/water,
v
/
v
; water), time (3, 5, 7, 9, and 10 min), temperature (30, 50, 60, and 80 °C), and acidity (addition of 10 % HCl) with advanced extraction techniques such as microwave-assisted extraction (MAE) on phenolic compounds in Dalmatian sage extracts. Total polyphenols were better extracted with 30 % aqueous media with acetone (
v
/
v
), without HCl at 80 °C for 10 min. Considering individual phenolic compounds, in all extracts, rosmarinic acid was predominant and better extracted with 30 % ethanol/added HCl at 80 °C. The optimal polyphenol extraction conditions were methyl rosmarinate (30 % ethanol/added HCl/32 °C), syringic acid (30 % ethanol/without HCl/80 °C), salvianolic acid (any solvent/without HCl/80 °C), caffeic acid (water/added HCl/78 °C), and vanillic acid (30 % ethanol/added HCl/80 °C).
The effect of extraction solvents (30, 50 and 70 % aqueous solutions of ethanol and acetone, and 100 % distilled water), extraction temperature (60 and 90°C) and extraction time (30, 60 and 90 min) ...on the composition and mass fraction of polyphenolic compounds in Dalmatian wild sage (Salvia officinalis L.) extracts has been investigated. The total polyphenolic content of sage extracts was determined spectrophotometrically using Folin-Ciocalteu method, whereas the individual polyphenols were determined by HPLC UV/PDA method. Results indicated that the main polyphenols in sage extracts were vanillic, caffeic, syringic, salvianolic K and salvianolic I acids, methyl rosmarinate, 6-hydroxyluteolin-7-glucoside, luteolin-7-glucuronide, luteolin-7-glucoside, apigenin-7-glucunoride, apigenin-7-glucoside, with rosmarinic acid and luteolin-3-glucuronide as predominant compounds. The mass fractions of total and individual polyphenols significantly depend on the type of extraction solvent, solvent composition and extraction temperature. The results showed that binary solvent systems are more efficient than mono-solvent systems in the extraction of polyphenolic compounds in regard to their relative polarity. The aqueous solutions of ethanol or acetone (30 %), extraction temperature of 60°C and extraction time of 30 min were the most efficient for the extraction of polyphenols from dry sage leaves. Key words: sage, phenolic acids, flavone glycosides, extraction parameters
In order to determine the optimal conditions for the extraction of sage polyphenols, the influence of extraction solvent (water, 30% (by volume) aqueous ethanol and 30% (by volume) aqueous acetone), ...extraction time (3, 5, 7, 9 and 11 min) and microwave power (500, 600 and 700 W) on the composition and concentration of phenolic compounds of dry wild sage (Salvia officinalis L.) during microwave-assisted extraction (MAE) was studied. Optimized MAE method was compared with conventional extraction (CE). Based on the amount of total phenols, microwave power of 500 W and extraction time of 9 min were selected as optimal extraction conditions, resulting in higher content of polyphenols when compared with CE. Ethanol and acetone solutions were equally effective extraction solvents, both producing higher extraction capacity than water. Using HPLC coupled with UV/PDA, fourteen polyphenols were identified (caffeic and rosmarinic acid derivatives, luteolin- and apigenin-glycosides) with rosmarinic acid and luteolin glycosides at the highest concentrations. The mass fractions of all individual polyphenols were higher in the MAE extracts than in the CE ones. Key words: sage, phenolic compounds, conventional solvent extraction, microwave-assisted extraction
U radu je istražen utjecaj otapala (30, 50 i 70 %-tne vodene otopine etanola ili acetona te 100 %-tne destilirane vode), temperature (60 i 90 °C) i vremena ekstrakcije (30, 60 i 90 min) na sastav i ...maseni udjel polifenola u ekstraktima samonikle dalmatinske kadulje (Salvia officinalis L.). Ukupni je udjel polifenolnih spojeva određen spektrofotometrijski pomoću metode Folin-Ciocalteu, dok su udjeli pojedinačnih fenolnih spojeva određeni metodom HPLC UV/PDA. Rezultati pokazuju da se u ekstraktima kadulje nalaze sljedeći fenolni spojevi: vanilinska, kafeinska, siringinska te salvianolna K i I kiselina, metil-rozmarinat, 6-hidroksiluteolin-7-glukozid, luteolin-7-glukuronid, luteolin-7-glukozid, apigenin-7-glukuronid, apigenin-7-glukozid, te ružmarinska kiselina i luteolin-3-glukuronid kao najzastupljeniji spojevi. Maseni je udjel ukupnih i pojedinačnih polifenolnih spojeva ovisio o tipu i sastavu otapala te temperaturi ekstrakcije. Rezultati pokazuju da se vodenim otopinama etanola ili acetona može ekstrahirati više polifenolnih spojeva nego samim otapalima, i to zbog njihove veće polarnosti. Najviše je polifenolnih spojeva ekstrahirano iz listova kadulje pomoću vodenih otopina etanola i acetona (30 %), pri temperaturi od 60 °C tijekom 30 min.
Da bi se odredili optimalni uvjeti ekstrakcije polifenola iz kadulje, ispitan je utjecaj otapala (voda, 30 %-tna vodena otopina etanola i 30 %-tna vodena otopina acetona), vremena ekstrakcije (3, 5, ...7, 9 i 11 min) i snage mikrovalova (500, 600 i 700 W) na sastav i koncentraciju fenolnih spojeva tijekom ekstrakcije potpomognute mikrovalovima (MAE). Optimirana MAE metoda je zatim uspoređena s konvencionalnom metodom ekstrakcije (CE). Na temelju količine ukupnih fenola odabrani su optimalni uvjeti snage mikrovalova od 500 W i vremena ekstrakcije od 9 min pri kojima je ekstrahirana veća količina fenolnih spojeva u usporedbi s CE. Etanol i aceton bili su podjednako učinkovita otapala s većom djelotvornošću ekstrakcije od vode. Primjenom HPLC UV/PDA identificirano je četrnaest fenolnih spojeva (derivati kafeinske i ružmarinske kiseline, glikozidi luteolina i apigenina) i to najveći udjeli ružmarinske kiseline i glikozida luteolina. Svih pojedinačnih fenolnih spojeva bilo je više u ekstraktima dobivenim MAE metodom.
Soluble or instant espresso coffee in capsules with added values is a product that is increasingly recognized as a healthy lifestyle habit, which often goes together with the expansion of spa centers ...and spa hotels. In addition to the theoretical and empirical examination of sustainable drinking habits regarding different types of instant espresso coffee in Serbia, the aim was to define, by applying the theory of planned behavior, the relationship between certain factors that influence instant espresso coffee beverage reselection. The research model was developed using a sample of 1385 soluble/instant espresso coffee consumers. Structural equation modeling was applied to test the conceptual model and research hypotheses. The results indicate a statistically significant influence of certain predictors on the intention of consumers to rechoose soluble/instant coffee. One exception is perceived behavioral control, where statistical significance exceeds the allowed values, which indicate that the offer of functional soluble/instant espresso solutions should be extended outside high-quality service hotels and spa centers to be available to all consumers with healthy lifestyle habits. Defining the factors that influence instant espresso coffee reselection can help to understand influences on certain consumer behaviors and improve sustainability on the market.
Stilbeneylsydnone derivatives were synthesized by a sequence of reactions in good yields. Irradiation of 3-stilbeneyl-4-methylsydnone
4 gives 1
H-1,2-benzodiazepine derivative
7 as the main product ...along with 2-methylquinoline derivative
20. Irradiation of 3-stilbeneyl-4-phenylsydnone
5 afforded only 1
H-1,2-benzodiazepine derivative
8 whereas on irradiation of 4-unsubstituted 3-stilbeneylsydnone
3 no benzodiazepine derivative was detected. An efficient novel photochemical approach to 1
H-1,2-benzodiazepines has been found from the new 3-(
o-stilbeneyl)-4-substituted-sydnones via intramolecular 1,7-electrocyclization reaction of the photogenerated nitrile imines.
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