Volatile compounds and long-chain aldehydes formation in conchocelis-filaments of a red alga, Porphyra tenera

Abstract

Abstract The essential oil in conchocelis-filaments of a red alga, Porphyra tenera was obtained by simultaneous distillation extraction. Volatile compounds in the oil were identified by GC and GC-MS. The major constituents were cubenol, phytol and long-chain aldehydes such as tetradecanal, pentadecanal, (8Z,11Z)-heptadecadienal and (8Z)-heptadecenal. The aldehydes were shown to be formed enzymatically in the filaments of the alga. The substrate specificity for the long-chain aldehyde forming activity from the conchocelis-filaments was different from the thalli of a green alga, Ulva pertusa , i.e. saturated fatty acids were better substrates than unsaturated fatty acids. The reactivity decreased with both an increase and a decrease in the chain length away from that of palmitic acid (16:0). The substrate specificity seemed to reflect the composition of the long-chain aldehydes present in the essential oil.