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Comparative analysis of six different brands of date fruits

Kursinszki L., Kalász H., Szőke É, Adeghate E, Hassan M. Y, Adem A

Acta Chromatographica

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2011

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Vol. 23, no. 4

603--610

EN

Flavonoid composition of six different brands of Phoenix dactylifera L. date fruit (Lulu, Khalas, Khenaiz, Al-Medina, Razaiz, and Fardh) was identified, determined, and compared. The separation was done on a Zorbax Eclipse XDB-C18 (150 × 4.6 mm ID) reversed-phase column using gradient elution of 1% aqueous formic acid (A) and acetonitrile (B). Gradient conditions were 00.00 min, 13% B; 20.00 min, 34% B; 25.00 min, 64% B; 29 min, 64% B; 35 min, 13% B; 39 min, 13% B. Monitoring was done using ultraviolet absorbance and MS/MS.

2

Triterpenes in traditional and supercritical-fluid extracts of Morus alba leaf and stem bark

Böszörményi A, Szarka Sz., Héthelyi É, Gyurján I, László M, Simándi B, Szőke É, Lemberkovics É

Acta Chromatographica

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2009

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Vol. 21, no. 4

659--669

EN

Our objectives were to establish a GC method capable of quantitative analysis of terpenoids without derivatisation and to examine the amount of β -sitosterol extracted from Morus alba L. leaf and stem bark by use of traditional organic solvent extraction and supercritical-fluid extraction (SFE). To measure β -sitosterol content without derivatization, GC-FID was used with 5- α -cholestan-3-one as internal standard. To identify terpenoid constituents, GC-MS was used; β -sitosterol, phytol, lanost-7-en-3-on, α -amyrin, β -amyrin, and lupeol were identified. We established that for Morus leaf the best SFE method for β -sitosterol was pilot scale SFE; the β -sitosterol content of this extract was higher than that of the hexane solvent extract. Among analytical SFE conditions, 200 bar for 90 min and 300 bar for 60 min resulted in extraction of the most β -sitosterol. For mulberry stem bark, solvent extraction with hexane and SFE at 400 bar and 40°C for 60 min proved the best methods.

3

HPLC monitoring of the microsomal stability of rutin and quercetin

Szőke É, Petroianu G., Tekes K., Benkő B, Szegi P., Laufer R., Veress G

Acta Chromatographica

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2009

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Vol. 21, no. 3

399--410

EN

Reversed-phase HPLC has been used to monitor the concentration of the two major Chamomile components rutin and quercetin during rat liver microsomal treatment. The possibility of microsomal oxidative metabolism or stability of these two components was examined using a guard-column without any clean-up. The concentration of quercetin decreased when exposed to rat liver microsomal media whereas the rutin concentration did not change significantly over one hour of treatment.

4

Betulaceae and platanaceae plants as alternative sources of selected lupane-type triterpenes. Their composition profile and betulin content

Felföldi-Gáva A, Simándi B, Plánder Sz., Szarka Sz., Szőke É, Kéry Á

Acta Chromatographica

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2009

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Vol. 21, no. 4

671--681

EN

Qualitative and quantitative analysis was performed on supercritical-fluid and conventional Soxhlet extracts of Betula pendula Roth., Alnus glutinosa (L.) Gaertn., and Platanus hybrida Brot. bark. The effect of the two extraction methods on extraction yields was compared. Lupeol and β-sitosterol were identified in the bark extracts by TLC and by GC-MS. The main components were betulin and lupeol followed by β-sitosterol; betulinic acid seemed to be a minor constituent. Betulin content was determined by RP-HPLC, with acetonitrile-water 80:20 ( v/v ) as mobile phase. Comparison of the extraction methods showed that supercritical-fluid (scCO 2 + EtOH) and ethanolic Soxhlet extraction resulted in the highest extraction yields. Accumulation of betulin derivatives was higher in supercritical-fluid extracts (scCO 2 + EtOH) than in conventional Soxhlet extracts.