Synthesis Of Novel Guanidine Compounds And Modification Of Glycyrrhetinic Acid

Isoxazole derivatives belong to the most active classes of compounds possessing a broad spectrum of biological activity, and are widely used in Pharmaceuticals and agrochemicals, among which a variety of reported compounds as good fungicides are commercially available already.The guanidine-containing compounds have also been employed as anti-microbials and fungicides on a considerable scale. The drags containing guanidine framework are not only easy to transport, but also make the functions of absorption and osmosis more selective due to the good solubility of their various acid salts in aqueous solution.According to the above facts, combining the isoxazole nucleus and guanidine framework might lead to more efficient herbicides.Glycyrrhetinic acid is one of the active ingredients of the licorice root, and it has a great variety of pharmacological properties including anti-inflammatory, anti-allergic, anti-nociceptive, anti-ulcer, anti-tumor, and anti-viral. However, a side-effect (induction of edema and hypertension) has been observed in patients given high doses of glycyrrhizin and glycyrrehtinic acid for prolonged period. This side-effect, a mineral corticoid-like action noted as pseudoaldosteronism, is due to the inhibition of the metabolic clearance of endogenous corticoid with the retention of Na+ and water and excretion of K+. Thus it is very important to modify its structure to look for more active drugs.Based on the others' study and according to the connection between the drug and the receptor, a series of novel glychrrhetinic acid isoxazole derivatives have been firstly synthesized and their chemical structures were confirmed by the methods of IR, ~1H NMR, and ESI-MS.