Chiral HPLC separation and simulation studies of two chiral centered bis-imino flavans (Schiff base)

The biological activities of flavanone and hesperetin were enhanced by synthesizing Schiff base types molecules (bis-imino-flavans; BHF4, BHF8 and BHF10) by combining flavanone and hesperetin. These molecules were characterized by spectroscopic studies. The four enantiomers of these molecules were separated by HPLC due to the presence of two chiral centers in these molecules. The best separation was achieved with Chiralcel®OD-H column under normal mobile phase mode. BFH4 and BFH8 racemates separated completely with k1, k2, k3 & k4; α1, α2 & α3 and Rs1, Rs2 & Rs3 values of 3.00, 3.55, 3.80 & 4.25; 1.18, 1.07 & 1.12 and 1.26, 1.10 & 1.00 for BFH4 while these values were 5.70, 6.30, 9.08 & 9.83; 1.11, 1.44 & 1.08 and 1.08, 1.37, 6.35 and 1.71. On the other hand, BHF10 could not separate completely. The free energy (ΔG) was calculated for the best separation conditions, and the correlation accurately shows the favorable range of the intercalated length. The chiral mechanism was proposed based on the carbon lengths between flavanone and hesperetin molecules in bis-imino-flavans. The modeling results confirmed the binding order of the enantiomers in BHF4 > BHF8 > BHF10; with maximum bing of SR-enantiomers. The synthesized and separated Schiff base types bis imino-flavans were evaluated in urine samples with satisfactory results.