Red algae have been studied extensively as sources of interesting metabolites (1, 2). The isolation of N-acylsphingosines have also been reported from the red algae (3). Previously we have reported the sterols and fatty acids of H. porphyroides (4). Here, we report the isolation of a new N-acylsphingosine, named halyminine (1), and the structural elucidation of its acetylated derivative 2, by spectroscopic methods. Calamintha grandiflora (L.) Moench (Syn. Satureja grandiflora (L.) Scheele) is a plant of the Labiatae family. This plant is a perenial herb (20—60 cm) (1) and has a strong and penetrating fragrance, particularly in July. There is no previous phytochemical study in the literature concerning the volatile constituents of this plant. A survey of the literature on Calamintha shows that the essential oils of 2 species have been investigated. The results showed that there are remarkable differences in the major constituents of their oils. On that basis, C. nepeta (L.) Savi (2) has as main constituents: pulegone, menthone, and isomethone, and C. nepeta (L.) Savi ssp. glandulosa (3): piperitone oxide, piperitenone oxide, and limonene. In this work we report on the composition of the oil obtained by steam distillation of the aerial parts of C. grandflora growing in Greece and compare it with the composition of oils reported in the literature (3).