Abstract: Ten compounds were isolated from the CH2Cl2/MeOH (1/1) stem bark extract of Piptadenia africana, a western Cameroonian plant species. These compounds included three new lactone derivatives piptadenol A-C. The known compounds include 5,6-dimethoxy-7-hydroxyflavone, antiquol B, sistosterol, β-amyrine, betulinic acid, cholesterol and 24(S)-stigmat-5,22-dien-3β-O-glucopyranoside. The latter was found to be highly promising α-glucosidase inhibitor. These compounds were characterized using physical and spectroscopic methods. The plant extract and 24(S)-stigmat-5,22-dien-3 β-O glucopyranoside showed antibacterial activity.