Minoru Shiga

Three sesquiterpenes from agarwood

Abstract Three new sesquiterpenes, (−)-guaia-1(10),11-dien-15-al, (−)-selina-3,11-dien-9-one, and (+)-selina-3,11-dien-9-ol, have been isolated from Aquilaria agollocha (agarwood). Their structures have been established on the bases of detailed spectroscopic analyses and synthesis. The odoriferous properties of these compounds are also described.

Long-chain aldehyde production in thalli culture of the marine green alga Ulva pertusa

Abstract The essential oil of bacteria- or epiphyte-free thalli culture regenerated from protoplasts of Ulva pertusa was obtained by a simultaneous distillation extraction procedure. The major flavour compounds in the oil of the culture were found to be long chain aldehydes such as (8 Z )-heptadecenal, (8 Z ,11 Z )-heptadecadienal and (8 Z ,11 Z ,14 Z )-heptadecatrienal as in the essential oil of the field fronds. These characteristic aldehydes were shown to be produced by alga enzymes and not by attached bacteria or other epiphytes. A particularly striking observation was that the substrate specificity for the long chain aldehyde-forming activity of the enzymes from the thalli culture was different to those from the field fronds; the best substrate used was oleic acid with linoleic acid an equally effective substrate for the enzymes from thalli culture.