Biotransformations of the sesquiterpene ketone nootkatonefrom the crude drug Alpiniae Fructus and grapefruit oil, and the sesquiterpene hydrocarbon valencenefrom Valencia orange oil were carried out with microorganisms such as Aspergillus niger, Botryosphaeria dothidea, and Fusarium culmorum to afford structurally interesting metabolites. Their stereostructures were established by a combination of