||With hydrogenchloride; In water; at 120℃; for 3h;
||General procedure: Compounds 1 and 2 (1mg each) were hydrolysed with 6MHCl (1ml) at 120 C for 3 h. The solutions were then evaporatedto dryness, and the residues were re-dissolved in 1mlof water and dried on a rotary evaporator. Next, 100 mul of 1Msodium bicarbonate was added to each residue to form solutions.Amino acid standards were also individually dissolvedin 100 mul of 1M sodium bicarbonate at concentrations of1mgml-1. The D, L-aminoheptanoic acid were purchasedfrom Aladdin Biochemical Technology and J&K Scientific.Thirty-five microlitres of Nalpha-(2,4-dinitro-5-fluorophenyl)-L-alaninamide (L-FDAA, Marfey?s Reagent, for threonine,leucine and tryptophan)  and 60mul Nalpha-(2,4-dinitro-5-fluorophenyl)-D/L-leucinamide (D/L-FDLA, advanced Marfey?sreagent, for alpha-aminoheptanoic acid)  in acetone(10mgml-1) was added to each solution. The solutions wereincubated in a water bath at 55 C for 1 h. After cooling toroom temperature, each solution was dissolved in MeCN forHPLC analysis. At 26 C, MeCN/H2O containing 0.1%HCOOH was used as mobile phase using the following gradient:0-5min, 20% MeCN; 5-35 min, 20-60% MeCN;35-40min, 60-100% MeCN and 40-50 min, 100-20%MeCN. The flow rate was 1 ml min-1 with UV detection at340 nm. The HPLC results for the amino acids were comparedto the results of the standard samples .