Evaluation of Synergistic Effect of Different Compositions of Liquid Extract of Citrus limonium and Its Linkage with β-cyclodextrin for the One-pot Multicomponent Synthesis of Pharmacological Bioactive Compounds with Application of Exploratory Analysis

Abstract

The ability of liquid extract of Citrus limonium and Citrus limonium-β-cyclodextrin composite to promote multicomponent reactions of pharmacologically bioactive compounds from a diversity of aromatic aldehydes has been described. Development of Citrus limonium-β-cyclodextrin composite was characterized using scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). Liquid extract of Citrus limonium efficiently catalyzed one pot two and three component reaction of α-aminophosphonates, 1H-benzo[d]imidazoles and 9,10-dihydrobenzo[a]xanthen-11(12H)-ones, whereas, Citrus limonium-β-cyclodextrin composite showed a higher catalytic activity for four component reaction of 6-amino-2,4-dihydro-3-methylpyrano[2,3-c]pyrazole-5-carbonitriles and 3,4-dihydro-2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-triones. The method is superior to the existing methods as catalysts provide less reaction time, easier workup and afford good to excellent yields under solvent-free condition. Application of principal component analysis and variable correlation analysis extract the information and further evaluate the catalytic efficiency of liquid extract of Citrus limonium and Citrus limonium-β-cyclodextrin composite. Also, PCA applied on catalytic activity of different constituents of liquid extract of Citrus limonium and their different ratios gave the idea of their synergistic effect for the synthesis of above pharmacological compounds.