Box-Behnken Design for Optimum Extraction of Biogenetic Chemicals from P. lanceolata with an Energy Audit (Thermal x Microwave x Acoustic): A Case Study of HPTLC Determination with Additional Specificity Using On-line/Off-line Coupling with DAD/NIR/ESI-MS

IntroductionThe genus Pluchea comprises about 80 species distributed worldwide, out of them, only Pluchea lanceolata (DC.) Oliv. & Hiern, is used extensively in the traditional system of India. No chromatographic method is available for its quality. ObjectivesTo perform the energy audit for the extraction of biogenetic pentacyclic triterpene, its acetate and sterol from P. lanceolata utilising organic and four alternative solvents. Additionally to resolve the uncertainty of TLC determination, on-line/off-line coupling with a diode-array detector (DAD), and near-infrared (NIR) and electrospray ionisation (ESI) MS was introduced. MethodsThe extraction of taraxasterol (Tx), taraxasterol acetate (TxAc) and stigmasterol (St) from P. lanceolata was performed using three energy modes. The effects of different operating parameters were studied for optimum extraction yield using the design of experiments, that is, the central composite design and Box-Behnken design. In addition to the retention factor (R-f) and visible spectral matching, two additional optical spectroscopic techniques, that is, NIR and ESI-MS, were applied for extended specificity. ResultsThe method was developed for Tx, TxAc and St determination using HPTLC at 645 nm. The optimum extraction yield of targeted compounds was found to be higher with organic solvents than eco-friendly surfactants. The pulse ultrasonic assisted extraction (PUAE) has resulted in optimum extraction of compounds comparable to hot extraction. Both NIR and ESI-MS provided extended specificity in determination. ConclusionThe 5/1-PUAE was determined to be effective, reproducible, simple and energy efficient for the determination of Tx, TxAc and St in P. lanceolata. The offline coupling of NIR and ESI-MS with HPTLC led to considerable improvement in specificity. Copyright (c) 2014 John Wiley & Sons, Ltd. A study of three different energy sources, using response surface methodology, for the extraction of three compounds of biogenetic importance from Pluchea lanceolata was made. Separation, quantification, specificity of determination, was carried out using densitometric HPTLC coupled with DAD, NIR and ESIMS. The validated HPTLC method for simultaneous detection of taraxasterol (Tx), taraxasterol acetate (TxAc) and stigmasterol (St) was found to be applicable to P. Lanceolata and is expected to be applicable other plants of Asteraceae family.