Thesis (M.Sc.)--Chulalongkorn University, 1999

One mixture and three compounds were isolated from the fresh tubers of Mucuna collettii Lace. by extraction, which made use of solvents and chromatographic techniques. These compounds were characterized by mean of physical properties, chemical reaction and spectroscopic data. The first mixture was a mixture of campesterol, stigmasterol and beta-sitosterol. The second and the third compounds were kaempferol and quercetin, respectively. But, as of now, is it still not possible to present the structural formula of the fourth compound. The effects of each compound in inhibiting cyclic AMP Phosphodiesterase were tested. It was found that kaempferol, quercetin and the fourth compound all took great effects in inhibiting cyclic AMP Phosphodiesterase. They had IC[subscript 50] value of 281.83, 80.91 and 22.75 microgram/ml, respectively. These values were compared to theophylline, which is the standard compound having an IC[subscript 50] value of 419.76 microgram/ml