Besides the known imide ritigalin (9), six new phenethyl/styrylamine-derived amides isolated from lipophilic leaf extracts of Glycosmis cf. mauritiana, Glycosmis cf. cyanocarpa, and Glycosmis crassifolia displayed pronounced antifungal and/or insecticidal activity against Cladosporium herbarum and Spodoptera littoralis, respectively, including the methylthiocarbonic acid derivatives niranin (1), dehydroniranin A (2), and dehydroniranin B (3) as well as the isovaleric and senecioic acid derivatives thalebanin B (4), dehydrothalebanin B (5), and dehydrothalebanin A (6). In the course of continuing search for new bioactive compounds from different Glycosmis species collected in Thailand, a series of novel amides with strong antifungal and insect-toxic properties were detected and isolated. Their structures were elucidated by spectroscopic methods and divided into two groups based on different acid moieties: the sulfur-containing moieties group (niranin (1), dehydroniranins A (2) and B (3)) and the group derived from isovaleric acid (thalebanin B (4)) or senecioic acid (dehydrothalebanins B (5) and A (6)).