2-Hydroxyvirensic Acid, a New Depsidone from the Lichen Sulcaria sulcata.

The new depsidone 2-hydroxyvirensic acid (4-formyl-2,3,8-trihydroxy-1,6,9-trimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepin-7-carboxylic acid) (6) has been isolated from a chemical race of the lichen Sulcaria sulcataand the structure (6) deduced from a combination of spectroscopic data.

A new chemical race of Monarda fistulosa (Labiatae)

A race, chemically distinct but morphologically similar to the widespread Monarda fistulosa L. var. menthaefolia (Graham) Fern., has been found to share the same habitat with the normal form in and around the Spruce Woods Forest Reserve in Manitoba.The foliage of the mutant form contained 0.7 to 1.1% oil on a fresh weight basis. This was about twice the quantity steam-distilled from the normal form. The oil from the mutant was 72 to 93% geraniol, previously unreported in Monarda. The mutant and normal forms cross readily, indicating no genetic isolating barriers have been established.

Terpenoid chemistry. XVII. ( - )-Ngaoine, a toxic constituent of Myoporum deserti. The absolute configuration of ( - )-Ngaione

Varieties of the shrub Myoporum deserti A. Cunn. (Ellangowan poison bush), which causes heavy losses of stock in inland Australia, yield at least nine different essential oils, most of which are toxic. One oil from plant material of the Longreach chemical race from Blackall, Clermont, Hannaford, Longreach, Meandarra, Moree, and Roma contains the toxic furanoid sesquiterpene ketone, (-)-ngaione, as the principal constituent while two others (the Mitchell and the Blackall races) contain lesser proportions of ngaione. (-)-Ngaione comprises over half of the essential oil of a "greenish leaf" variety of Eremophila latrobei F. Nuell. and a low proportion of the oil of a "silver leaf" variety of the same species. The trans isomer of ngaione [(-)-epingaione], present in low concentration in some of these essential oils, is formed from ( -)-ngaione during fractional distillation or more rapidly by base-catalysed epimerization. "Isongaione acetate" prepared from (-)-ngaione by treatment with acetic anhydride-sodium acetate is shown to be a mixture of a, β- and β, γ-unsaturated ketones and obtainable in optically active form contrary to literature statements. Oxidation of the optically active β,γ-unsaturated ketone yields (-) acetylmalic acid from which it follows that (-)-ngaione is l(S),4(R)-β-(4,8-dimethyl-6-oxo-1,4-epoxynonyl)furan, ipomeamarone is the 1(R),4(S) enantiomer, and (-)-epingaione is the 1(S),4(S) isomer.