Response surface methodology-based optimization of ultrasound-assisted extraction of β-sitosterol and lupeol from Astragalus atropilosus(roots) and validation by HPTLC method

Objective:To optimize the ultrasonication method for efficient extraction ofβ-sitosterol and lupeol from the roots of Astragalus atropilosus using Box-Behnken design of response surface methodology(RSM),and its validation by high performance thin layer chromatography(HPTLC)method.Methods:Ultrasonication method was used to extractβ-sitosterol and lupeol from Astragalus atropilosus(roots).RSM was used to optimize the different extraction parameters viz.liquid to solid ratio(10–14 m L/g),temperature(60-80℃)and time(40–60 min)to maximize the yield ofβ-sitosterol and lupeol.The quantitative estimation ofβ-sitosterol and lupeol was done in chloroform extract of Astragalus atropilosus by validated HPTLC method on 10 cm×20 cm glass-backed silica gel 60 F254 plate using hexane and ethyl acetate(8:2,v/v)as mobile phase.Results:A quadratic polynomial model was found to be most appropriate with regard to R1(yield of total extraction;R2/%CV=0.9948/0.28),R2(β-sitosterol yield;R2/%CV=0.9923/0.39)and R3(lupeol yield;R2/%CV=0.9942/0.97).The values of adjusted R2/predicted R2/signal to noise ratio for R1,R2,and R3 were 0.9782/0.9551/48.77,0.9904/0.9110/31.33,and 0.9927/0.9401/36.08,respectively,indicating a high degree of correlation and adequate signal.The linear correlation plot between the predicted and experimental values for R1,R2,and R3 showed high values of R2 ranging from 0.9905-0.9973.β-sitosterol and lupeol in chloroform extract of Astragalus atropilosus were detected at Rf values of 0.22 and 0.34,respectively,atλmax=518 nm.The optimized ultrasonic extraction produced 8.462%w/w of R1,0.451%w/w of R2 and 0.172%w/w of R3 at 13.5 m L/g liquid to solid ratio,78℃of temperature and 60 min of time.Conclusions:The experimental findings of RSM optimized extraction and HPTLC analysis can be further applied for the efficient extraction ofβ-sitosterol and lupeol in other species of Astragalus.

Acetylcholinesterase and Cytotoxic Activity of Chemical Constituents of Clutia lanceolata Leaves and its Molecular Docking Study

Phytochemical investigations of the ethanolic extract of leaves of Clutia lanceolata(Family:Euphorbiaceae)resulted in the isolation of four compounds viz.3,4-dihydroxy-2-methylbenzoic acid(1),2,20-dihydroxy-1,10-binaphthyl(2),1,3,8-trihydroxy-6-methylanthracene-9,10-dione(3)and 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one(4).Although all the isolated compounds were known but this was the first report from this plant source.Their structures were established on the basis of chemical and physical evidences viz.elemental analysis,FT-IR,1 H-NMR,13CNMR and mass spectral analysis.Structure of compound 2 and 4 was further authenticated by single-crystal X-ray analysis and density functional theory calculations.The isolated compounds(1–4)were screened for AChE enzyme inhibition assay in which compound 3 and 4 were found to be more potent AChE inhibitor.Molecular docking study of potent AChE inhibitor was performed to find the probable binding mode of the compounds into the active site of receptor.Moreover,the isolated compounds were also screened for in vivo cytotoxicity by brine shrimp lethality assay.