In Vitro and In Silico Studies of Secang Wood ( Caesalpinia sappan L.) Extracts and Brazilin as Natural Phosphodiesterase-1 (PDE1) Inhibitor for Herbal Cognitive Enhancer Development

[...]the ethanol extract of CS wood and its major constituent, brazilin, inhibited PDE1 activity and could be develop as cognitive enhancer. [...]vinpocetine causes undesirable side-effects, such as stomach pain, nausea, sleep disturbances, headache, dizziness, nervousness and flushing16-20. [...]an alternative PDE1 inhibitor, especially from natural resources is needed. The 5'AMP concentration of sample was calculated by the standard 5'-AMP linear regression equation and then the inhibition percentage was calculated with the following formula: (ProQuest: ... denotes formula omitted.) Where; A = 5'-AMP negative control B = 5'AMP tested sample Thin Layer Chromatography (TLC) Analysis: The tested extracts and brazilin were analyzed by TLC using silica gel F254 and chloroform: acetone: formic acid (4:2:0.5 v/v) as the stationary and mobile phase, respectively. The observation includes free-bond energy (AGbind) (kcal/mol), bond length (Å), conformation pose of protein-ligand complex and interactions between the tested compounds and amino acid residues at the active site of PDE1B.