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  • Author or Editor: Sagar Mishra x
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An efficient, sensitive, and precise high-performance thin-layer chromatographic (HPTLC) method has been established for analysis of 6-gingerol in marketed Ayurvedic formulations and in the rhizomes of different varieties of Zingiber officinale . HPTLC separation was performed on aluminum foil-backed HPTLC plates coated with 0.2-mm layers of silica gel 60 F 254 , with n -hexane-acetone, 7.2:2.8 ( v/v ) as mobile phase. Plates were developed to a distance of 78 mm at 20 ± 4°C in a chamber previously saturated for 4 min. Under these condition the retention factor ( R F ) of 6-gingerol was 0.23 and the compound was quantified at 286 nm, its wavelength of maximum absorbance. The limits of detection and quantification were 40 and 150 ng per band, respectively. Response to 6-gingerol was a linear function of amount over the range 150 to 900 ng per band; the correlation coefficient was 0.9997, indicating a good relationship between peak area and amount. Recovery from 98.46 to 101.11% showed the accuracy of the method was excellent. The method is very accurate, simple, and cost effective, and enables sensitive quantitative analysis of 6-gingerol.

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HPTLC has been used for quantitative analysis of aloin, as marker compound, in commercial Ayurvedic preparations, in the solid dosage form, containing Aloe vera Linn as major herbal ingredient. Chromatography was performed on aluminum plates coated with 0.2-mm layers of silica gel 60 F 254 , with ethyl acetate-methanol-water 10:1.4:1 ( v/v ) as ternary mobile phase after saturation at 30 ± 4°C for 5–7 min. The development distance was 70 mm. Aloin was quantified at 360 nm, its wave length of maximum absorbance. The limits of detection and quantification were 10 and 20 ng per band, respectively. Regression analysis of the calibration data revealed a good linear relationship ( r = 0.9998) between peak area response and concentration in the range 20 to 100 ng per band. Instrumental precision and the repeatability of the method were 0.44% and 0.89% (CV), respectively. The accuracy of the method, determined by measurement of recovery at three different levels, was in the range 98.13 to 99.75%. These results are indicative of the excellent reliability, reproducibility, accuracy, and precision of the method. The method has been successfully used for analysis of aloin in commercial formulations containing Aloe vera .

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A high-performance thin-layer chromatography (HPTLC) method has been developed and validated for the quantification of two bioactive lupane triterpenoids, namely, lupeol and betulin from Diospyros melanoxyon stem bark. Chromatographic separation was achieved on aluminium foil-backed HPTLC plates using ethyl acetate-hexane (1.8:8.2, v/v) as mobile phase. The compounds were quantified at their wave length of maximum absorbance in the range of 100–500 ng per spot. The instrumental precision was 0.82% and 1.07% (CV) and the repeatability of the method was 1.33% and 1.17% (CV), respectively, for lupeol and betulin. The minimum detectable amount was found to be 40 and 50 ng per spot for lupeol and betulin, respectively. The linear regression analysis data for the calibration plots showed a good linear relationship with r 2 = 0.9996 for lupeol and 0.9997 for betulin. The method was validated for precision, recovery, and repeatability as per the International Conference on Harmonization guidelines. The developed HPTLC method is very accurate and precise, and has been successfully applied for the assay of these bioactive molecules in D. melanoxylon stem bark.

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A simple, sensitive, and rapid high-performance thin layer chromatographic (HPTLC) method has been established for estimation of piperine in commercial Ayurvedic formulations and in the fruits of Piper nigrum Linn, and Piper longum Linn. Chromatography was performed on aluminum foil HPTLC plates coated with 0.2 mm layers of silica gel F 254 , with hexane-acetone 6.5: 3.5 ( v/v ) as mobile phase. The development distance was 76 mm, the temperature 25 ± 5°C, and the chamber was saturated for 5 min. Piperine was quantified at 340 nm, its wavelength of maximum absorbance. Under the conditions used the R F of piperine was 0.33 and the limit of detection (LOD) was 4 ng per zone. The calibration plot was linear in the range of 10 to 60 ng per zone with a correlation coefficient of 0.9996. Recovery was in the range 98.76 to 100.70%. This HPTLC method was found to be reproducible, accurate, and precise and could be used to detect piperine at nanogram levels. The method is a very simple and cost-effective means of quantitative estimation of piperine in Ayurvedic formulations.

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The bioactive molecule, α-amyrin acetate, was isolated from the nhexane extract Streblus asper stem bark by column chromatography. The structure of the compound was characterized with the help of physical and spectroscopic data. A high-performance thin-layer chromatography (HPTLC) method has been developed and validated for its quantification in S. asper leaf, stem bark, and root. Chromatographic separation of the compound was achieved on high-performance precoated TLC plates by using optimized binary mobile phase consisting of n-hexane-ethyl acetate (9.6:0.4, v/v). HPTLC scanning was performed at 472 nm after derivatization of the plate with methanol-sulphuric acid reagent in reflection/absorption mode. The method was validated according to International Conference on Harmonization (ICH) protocol for specificity, sensitivity, linearity, accuracy, precision, repeatability, and robustness. The developed method is found to be very simple, rapid, precise, sensitive, and accurate for the quantification of α-amyrin acetate in S. asper.

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