Wyniki wyszukiwania - Biblioteka Nauki

1

Optimization of (2E)-3,7-dimethyl-2,6-octadien-l-ol (geraniol) transformation process parameters using Response Surface Method (RSM)

100%

Fajdek-Bieda A. , Wróblewska A.

Polish Journal of Chemical Technology

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2024

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tom Vol. 26, nr 1

24--38

EN

This paper presents the results of studies on the transformation of geraniol (GA) in the presence of the natural mineral bentonite. The paper determines the influence of temperature, catalyst content, and reaction time on the course of the process. In order to determine the most favorable process conditions, the catalytic tests were carried out without solvent and under atmospheric pressure. Three functions were chosen to determine the most favorable process conditions: GA conversion and the selectivities of the main products: linalool – LO and beta-pinene – BP. In addition, the paper optimize GA transformation process based on response surface methodology (RSM). The impact of the most relevant process indicators was presented. For all factors of the method, their effects on all primary parameters were determined in the form of second-degree polynomials, and such process conditions were determined to achieve their maximum.

2

Isolation of citronellal and geraniol from citronella (Cymbopogon winterianus) oil by vacuum fractional distillation: Effect of operating conditions on the separation

100%

Le M.-T. , Vu D.-P. , Nguyen T. N. , Le X.-T.

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2023

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tom Vol. 25, nr 4

67--80

EN

This study used fractional distillation to separate citronellal and geraniol from citronella (Cymbopogon winterianus) essential oil to improve their market value. The one-factor-at-a-time methodology investigated operating parameters’ optimum conditions and effects, including system pressure, packing types, and column height. All investigations were evaluated based on their main fraction’s citronellal and geraniol content and recovery. Regarding the effect of the variables, a higher system pressure improved the separation while increasing the temperature range of each fraction and distillation time. The packing types would also improve the separation by providing a large surface area. Finally, the column height also positively impacted the separation. In the optimum citronella oil fractionation, citronellal content experienced a 2.5-fold increase, from 37.68% to 94.33%. Geraniol purity reached 40.61% from an initial content of 17.33% in the raw CW oil. The distillation could recover up to 90.00% of citronellal and 68.18% of geraniol.

3

Green method of conversion of geraniol to value-added products in the presence of selected minerals

100%

Fajdek-Bieda A. , Wróblewska A. , Perec A. , Miądlicki P.

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2023

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tom Vol. 25, nr 1

47--60

EN

The study presents the results of research on the process of geraniol (GA) transformation in the presence of natural minerals: montmorillonite, mironekuton, halloysite and also in the presence of halloysite modified with 0.1 M water solution of H2SO4. To obtain information on the structure of the used catalysts, instrumental studies were performed (SEM, XRD, FT-IR, XRF, BET). The second part of the research consisted in examining the influence of individual parameters (temperature, catalyst content, and reaction time) on the course of GA transformation process. The syntheses were carried out without the application of solvent and under atmospheric pressure. To determine the most beneficial process conditions, two functions were selected: GA conversion and selectivity of GA. The proposed method of GA transformation on such minerals: montmorillonite, mironekuton, halloysite, has not been described in the literature so far.

4

Prenyl sulfates as alkylating reagents for mercapto amino acids

86%

Maltsev S. , Sizova O. , Utkina N. , Shibaev V. , Chojnacki T. , Jankowski W. , Swiezewska E.

Acta Biochimica Polonica

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2008

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tom 55

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nr 4

807-813

EN

A new methodology for prenylation of thiol compounds has been developed. The approach is based on the use of prenyl sulfates as new reagents for S-prenylation of benzenethiol and cysteamine in aqueous systems. The C10-prenols geraniol and nerol that differ in the configuration (E or Z, correspondingly) of the α-isoprene unit were efficiently O-sulfated in the presence of a pyridine-SO3' complex. The obtained geranyl and neryl sulfates were tested as alkylating agents. These compounds were chosen to reveal the influence of the α-isoprene unit configuration on their alkylation (prenylation) ability. S-Geranyl cysteine was prepared to demonstrate the applicability of this method for prenylation of peptides containing mercapto amino acids.

5

Evaluation of chemical composition of essential oils derived from different Pelargonium species leaves

81%

Szutt A. , Dołhańczuk-Śródka A. , Sporek M.

Ecological Chemistry and Engineering. S

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2019

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tom Vol. 26, nr 4

807--816

EN

Plants have been used for their aromatic and medicinal purposes for centuries. The genus Pelargonium contains about 250-280 species and cultivated around the world for the production of essential oils and absolutes. Pelargonium species are remarkable for their odour diversity, from fresh, lemon and minty scent, through floral, rose, fruity up to spicy and camphoreous smell as well as many health beneficial properties, that is why their essential oils are widely used in perfume, cosmetic, food and pharmaceutical industries. The aim of this study was to determine variability in populations of Pelargonium genus by evaluating their differences in quantitative and qualitative essential oils compositions. This study determined that of all the examined essential oil, the one of P. graveolens indoor cultivar has the closest C:G ratio (1.16) which makes it a very valuable product. In comparison with available literature, beside the geographical region of plant growth, all essential oils from P. graveolens contain a diverse range of compounds, nevertheless, in every single one, geraniol and citronellol are present in the most significant fraction of the total oil. The examined P. roseum essential oil was characterized by the highest level of citronellol (44.62 % of total oil), but it can be due to the chemical reactions (conversion geraniol into citronellol) occurring in stored product.

6

Rodzaj Thymus L. - walory aromatyczne i lecznicze. Przegląd wybranych gatunków

81%

Nurzynska-Wierdak R. , Chrapek A.

Annales Horticulturae

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2022

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tom 31

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nr 2

7

Otrzymywanie środków zapachowych na drodze utleniania terpenów z wykorzystaniem zasad zrównoważonej chemii

81%

Feliczak-Guzik A. , Nowak I.

Wiadomości Chemiczne

|

2010

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tom [Z] 64, 9-10

787-808

EN

The review presents some of the key catalytic transformations of a major monoterpene feedstocks. Green chemistry is a philosophy of chemical research and engineering that encourages design of products and processes that reduce the use and generation of dangerous substances. Thus one of the challenging goals of organic synthesis and catalysis is to develop stable heterogeneous catalysts capable to operate at ambient conditions perform selectivity as high as that of homogeneous catalysts. Terpenes represent one of the largest and most diverse classes of compounds, with over 55,000 members isolated to date. Their further oxidation and rearrangement results in an almost endless number of conceivable structures. Monoterpenes are key ingredients in the flavor and fragrance industry, with α- and β-pinene (obtained from turpentine) being some of the most important. The review focuses on the terpenes: pinene, limonene, and the interconversion of the monooxygenates: geraniol, nerol, citronellol, and citronellal. The major areas covered are catalytic hydrogenation/hydrogenolysis, dehydrogenation, rearrangement/ isomerization. However, this review focuses mainly on the oxidation of pinene and geraniol on heterogeneous catalysts.

8

Proba okreslenia wplywu linaloolu, geraniolu i alfa-terpineolu na wlasciwosci sensoryczne piwa

72%

Baranowski K.

Przemysł Fermentacyjny i Owocowo-Warzywny

|

1993

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tom 37

|

nr 07

1-3

PL

adano wpływ wybranych składników olejków chmielowych: linaloolu, geraniolu i α-terpineolu na właściwości sensoryczne piwa oraz podjęto próbę określenia optymalnych zawartości tych związków w piwie. W tym celu do piwa o zawartości 12% ekstraktu i 20 mg/l izozwiązków, wyprodukowanego w skali mikrotechnicznej z brzeczki przemysłowej oraz z chmielu aromatycznego ,,Lubelski", dodawano jednocześnie w różnych stężeniach linalool, geraniol i α-terpineol. Przygotowane próbki oceniano pod względem smaku, zapachu i goryczy przy udziale 8 degustatorów. Ze statystycznego opracowania punktowych ocen sensorycznych wynika, że w wyższych stężeniach linalool, geraniol i α-terpineol wywierają negatywny wpływ na cechy sensoryczne piwa, przy czym w przypadku geraniolu wpływ ten jest największy. W niskich stężeniach wpływ linaloolu i α-terpineolu jest pozytywny.

EN

The effect of selected components of volatile oils of hop: linalool, geraniol and α-terpineol on sensoric properties of beer was investigated. Moreover, an attempt of determining optimal values of these compounds in beer has been undertaken. For this purpose to the beer containing 12% extract and 20 mg/l compounds, produced in the microtechnical scale from industrial wort and from aromatic hop ,,Lubelski", linalool, geraniol and α-terpineol in different concentrations were added simultaneously. The samples prepared in such a way were estimated with regard to taste, smell and bitterness by 8 degustators. Statistical analysis of sensoric estimates in scores has proved that linalool, geraniol and caterpineol affect negatively the sensoric traits of beer, most strongly in case of geraniol. The effect of linalool and α-terpineol in low concentrations proved to be positive.

9

Prenyl sulfates as alkylating reagents for mercapto amino acids

72%

Maltsev S. , Sizova O. , Utkina N. , Shibaev V. , Chojnacki T. , Jankowski W. , Swiezewska E.

Acta Biochimica Polonica

|

2008

|

tom 55

|

nr 4

807-813

EN

A new methodology for prenylation of thiol compounds has been developed. The approach is based on the use of prenyl sulfates as new reagents for S-prenylation of benzenethiol and cysteamine in aqueous systems. The C10-prenols geraniol and nerol that differ in the configuration (E or Z, correspondingly) of the α-isoprene unit were efficiently O-sulfated in the presence of a pyridine-SO3,complex. The obtained geranyl and neryl sulfates were tested as alkylating agents. These compounds were chosen to reveal the influence of the α-isoprene unit configuration on their alkylation (prenylation) ability. S-Geranyl cysteine was prepared to demonstrate the applicability of this method for prenylation of peptides containing mercapto amino acids.

10

The content of essential oil in ten sweet basil [Ocimum basilicum L.] cultivars and its composition

72%

Seidler-Lozykowska K. , Krol D.

Herba Polonica

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2008

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tom 54

|

nr 3

EN

The experiment was conducted in the Research Institute of Medicinal Plants in Poznań, Poland in 2005–2006 and concerned a collection of ten sweet basil cultivars such as: ‘Minette’, ‘Mittelgrossblättriges Grünes’, Piccolino’, ‘Rubin’, ‘Red Rubin’, ‘Genoveser’, ’Martina’ and two Polish cultivars: ‘Wala’ and ‘Kasia’. Moreover, ‘Lemonette’ cultivar of Ocimum americanum L. was also included in the collection. The content of essential oil in the dried herb was estimated and its composition was analyzed. The content of essential oil in the dried herb without stems ranged from 0.23% (‘Red Rubin’) to 1.67% (‘Kasia’). The main component of the oils that came from nine basil cultivars was linalool, (from 37.07% for ‘Piccolino’ to 76.22% for ‘Minette’). Considerable amounts of 1,8-cineol and eugenol, next β-pinene, α-terpinene and myrcene were also found. The content of 16 identified components in oil represented from 69.34% (‘Piccolino’) to 96.11% (‘Wala’) of the GC profiles. Both Polish cultivars were distinguished by high content of geraniol in essential oil.

PL

W latach 2005–2006 w Instytucie Roślin i Przetworów Zielarskich badano kolekcję składającą się z 10 odmian bazylii pospolitej: ‘Minette’, ‘Mittelgrossblättriges Grünes’, Piccolino’, ‘Rubin’, ‘Red Rubin’, ‘Genoveser’, ’Martina’, ‘Wala’, ‘Kasia’ oraz odmiany ‘Lemonette’ należącej do gatunku Ocimum americanum. W suchym, otartym zielu oznaczano zawartość olejku eterycznego oraz jego skład. Zawartość olejku wynosiła od 0,23% (‘Red Rubin’) do 1,67% (‘Kasia’). Głównym składnikiem olejków pochodzących z 9 odmian był linalol (od 37,07% w ‘Piccolino’ do 76,22% w ‘Minette’). Inne składniki olejku o znacznym udziale to 1,8-cyneol, eugenol, β-pinen, α-terpinen oraz mircen. Obie polskie odmiany ‘Wala’ i ‘Kasia’ wyróżniały się wysoką zawartością geraniolu w olejku.

11

Biological activity of essential oil from aerial parts of Artemisia aucheri Boiss. from Iran

58%

Mahboubi M. , Bidgoli F. G.

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2009

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tom 55

|

nr 4

96-104

EN

Artemisia aucheri Boiss. is a shrub from Asteraceae family has been widespread in Iran. In traditional medicine, A. aucheri is used for its astringent, disinfectant, antimicrobial and antiparasitic properties. The aim of this study was to evaluate the chemical composition and antimicrobial activity of essential oil from aerial parts of A. aucheri against different microorganisms including Gram positive, Gram negative bacteria, filamentous fungi and yeast by disc diffusion and micro broth dilution assays. The antioxidant activity of A. aucheri essential oil was evaluated by DPPH free radical scavenging system. Fifty five components were identified by GC and GC/MS analysis and quantified from the essential oil of A. aucheri, representing 98% of total oil. The major components were geranyl acetate (17.2%), E-citral (17.1%), linalool (12.7%), geraniol (10.7%), Z-citral (10.5%). The antimicrobial results showed that Pseudomonas aeruginosa was resistant to the oil and Staphylococcus aureus and Candida albicans showed the best sensitivity to the oil. The A. aucheri has powerful antioxidant activity than that of Trolox. Some investigations were be done for evaluating the efficacy of essential oil.

PL

Artemisia aucheri Boiss. jest krzewem z rodziny Asteraceae rozpowszechnionym w Iranie. W medycynie tradycyjnej A. ancheri jest używana jako środek ściągający, odkażający, przeciwbakteryjny i przeciwpasożytniczy. Celem niniejszej pracy było określenie składu chemicznego i działania antybakteryjnego części nadziemnych Artemisia aucheri przeciwko różnym mikroorganizmom, w tym bakteriom Gram-dodatnim i Gram-ujemnym, grzybom nitkowatym i drożdżakom za pomocą metody dyfuzji krążkowej i metodą rozcieńczeń. Działanie antyutleniające olejku eterycznego z A. aucheri określono metodą z użyciem DPPH. Stosując GC i GC/MS zidentyfikowano 55 składników olejku i określono ich zawartość w olejku eterycznym A. aucheri (stenowiło to 98% całości olejku). Głównymi składnikami były: octan geranylu (17,2%), E-citral (17,1%), linalool (12,7%) i Z-citral (10,5%). Badania działania przeciwbakteryjnego wykazały, że oporny na działanie olejku był Pseudomonas aeruginosa, natomiast najbardziej wrażliwe były Staphylococcus aureus i Candidia albicans. Działanie przeciwutleniające A. aucheri jest tak samo silne jak działanie Troloxu. Dla określenia skuteczności działania olejku eterycznego konieczne są dalsze badania.

12

Kryteria i zasady oceny jakosci chmielu

58%

Baranowski K.

Przemysł Spożywczy

|

1996

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tom 50

|

nr 09

23-25

PL

Przedstawiono najważniejsze kryteria i zasady oceny jakości chmielu stosowane przez przemysł piwowarski oraz handlowców i przetwórców, opisane w Polskiej Normie (PN-R-50255 „Chmiel Piwowarski"). Z punktu widzenia przede wszystkim przemysłu piwowarskiego najważniejszym kryterium jakościowym chmielu goryczkowego i jego produktów jest stała, niezmienna w czasie i zgodna z deklaracją producenta zawartość w nim alfa-kwasów, a dla chmielu aromatycznego i jego produktów zawartość składników olejków chmielowych odpowiedzialnych za powstawanie w piwie charakterystycznego zapachu i smaku chmielowego. Dla handlowców i przetwórców, a także dla przemysłu piwowarskiego istotna jest tzw. jednorodność odmianowa chmielu, wilgotność chmielu, jak również rodzaj stosowanych przez plantatora środków ochrony roślin.

EN

The most important criteria and principles of evaluation of hops quality useful for breweries, merhants and processors, described at the Polish norm PN-R-50255 Hop has been presented. From the point of view of breweries the most significant criterion of quality for a bitter hop and its products is a constant, invariable and according with producer declaration contents of acid and for an aromatic hop and its products is a contents of hop oil componds which are responsible for characteristic hop flavour in beer. Homogeneus hop varieties, hop humidity and the kind of pesticides used by cultivators are also significant for merchands, processors and brewery industry.

13

Postrzeganie zapachu. O roli zapachów w życiu rodziny pszczelej słów kilka

51%

Janiszewska K.

Pasieka

|

2010

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nr 3