A Contribution to the Study of Natural Products

Abstract

A. The tricyclic sesquiterpene of D. kirkii, which yields an azulene on dehydrogenation and forms a liquid hdrochloride, is probably identical to the tricyclic sesquiterpene of D. cupressinum and D. biforme. There are at least three sesquiterpene alcohols present, in addition to the new solid alcohol, m.p. 42-43°. Two of these alcohols form liquid hydrochlorides and give S-guaiazulene on dehydrogenation, while the third is probably a new cadinol. B. The diterpene fraction of the essential oil of Araucaria excelsa has been shown to contain, besides phyllocladene, a further constituent the isomeric hydrocarbon isophyllocladene. The melting point diagram for mixtures of phyllocladene and isophyllocladene has been constructed and shows a eutectic at 50%. The occurence if isophyllocladene along with phyllocladene in nature is probably more widespread than is at presnt thought. C. Methyl salicylate occurs in the uncombined state in the fern, Asplenium lamprophyllum and is absent from the morphologically closely related A. bulbiferum. It is possible to distinguis by taste and smell these two ferms when they are morphologically almost identical. None of the other Aspleniums yet examined have been found to contain methyl salicylate.