Publications

Publications serve as the concrete art form for the scientist. It is his modus operandi. Authorship is akin to success and achievement. It cannot and should not deteriorate into a bargaining tool or commodity. Dardik
Kamatou, G.P.P., Chen, W., Viljoen, A.M. 2012. Quantification of rosmarinic acid in Salvia species indigenous to South Africa by HPTLC. Journal of Planar Chromatography 5: 403-408.

The genus Salvia (Lamiaceae) encompasses about 900 species worldwide of which 26 are found in southern Africa. Salvia spp have several medicinal uses in South Africa such as antimicrobial, anticancer, antimalarial and antituberculosis properties. Rosmarinic acid (RA) has been identified as one of the major molecules responsible for these various medicinal properties. Eleven Salvia species (18 samples) collected at different localities in South Africa were extracted with methanol in order to determine the level of RA present in the extracts. HPTLC analysis was performed on glass silica gel 60 F254 plates developed with ethyl acetate, toluene and formic acid (6:3:1, v/v), while a gradient of acetic acid and methanol was used for HPLC–UV analysis. Densitometric quantification was performed at λ = 328 nm (the wavelength of maximum absorption of RA) by fluorescence scanning using a CAMAG TLC scanner III. Polynomial regression (HPTLC) and linear regressions (HPLC–UV) analyses were used to determine the amount of RA in the extracts. The mobile phase used for HPTLC produced good separation for RA (Rf = 0.42). A good polynomial regression model was obtained in the range of 100–1000 ng and peak areas and heights with the correlation coefficient (R2) of 0.9995 and 0.9992, respectively. The limits of detection and quantification were 59.61 and 180.64 ng per band, respectively. The relative percentage standard deviations (RSD) of intra-day and inter-day precision of RA at 400 ng per band were 1.63 and 2.01, respectively. Salvia runcinata contained the highest (143.92 μg mg-1) RA content. The paired sample t-test showed no statistical significant difference in the estimation of the amount of RA in the solvent extracts using the two chromatographic techniques. The prescribed method is simple, fast, reliable, sensitive and here proposed for the routine assay of Salvia extracts containing RA.




Salvia african-caerulea | Lamiaceae | bloublomsalie | flower | botanical - Harold Porter Botanical Garden, Betty's Bay, Western Cape, South Africa [2008 © alvaroviljoen.com]