Metabolites and oximes with vasodilator and hypotensive activity

A method of preparing semi-synthetic oximes, comprising:

• a) applying an extract of S. nutans or X. poposum plants to a chromatographic column or a thin layer chromatography plate to obtain a metabolite of formula:
• wherein R corresponds to H, OH or methyl;
• R′ and R″ corresponds to H, methyl, propyl, propylene, 3-methylbutyl-2-ene, or R′ and R″ together form a dihydrobenzofuran derivative;
• b) heating under reflux between 100 mg to 400 mg of the metabolite obtained from step a) with a mixture of from 30 to 250 mg of hydroxylamine hydrochloride dissolved in 5 mL of ethanol and from 150-400 pL of pyridine at 40° C.-60° C. for 18-38 hours;
• c) separating the organic phase from the reaction mixture by liquid-liquid extraction using an organic solvent selected from dichloromethane, chloroform, ethyl acetate or ethyl ether;
• d) concentrating the organic phase on a rotary evaporator;
• e) purifying the oxime by silica gel column chromatography, wherein each column progress is monitored by thin layer chromatography.