Lois M. Browne

The camalexins : new phytoalexins produced in the leaves of Camelina sativa (cruciferae)

Abstract Two new thiazoyl substituted indole phytoalexins, camalexin (5) and methoxycamalexin (8), were isolated from Camelina sativa leaves following elicitation by the fungus Alternaria brassicae.

Some biologically active tannins of Nuphar variegatum

Abstract An aqueous solution of the roots of the Canadian water lily, Nuphar variegatum , has been found to be active in antibacterial assays. The chemistry of the solution has been investigated and the metabolites responsible for the antibacterial activity, the new gallotannin 1,2,3,4-tetrakis(3,4,5-trihydroxybenzoyl)-α- d -glucopyranose, a second gallotannin, and two ellagitannins have been isolated and identified.

Three piperazinediones and a drimane diterpenoid from Penicillium brevi-compactum

Abstract Three new piperazinedione metabolites isolated from cultures of Penicillium brevi-compactum are described. A drimane derivative similar to macrophorin A was isolated and characterized.

Resistance to Rhizoctonia solani and Presence of Antimicrobial Compounds in Camelina sativa Roots

Camelina sativa (L.) Crantz was significantly more resistant to Rhizoctonia solani Kühn than [itBrassica napus L. cv Westar. Emergence of C. sativa seedlings was 22 to 33% greater than those of Westar in R. solani-infested soil. The greater resistance of C. sativa seedlings to R. solani appeared to be due to greater amounts of antimicrobial compounds present in C. sativa roots. These antimicrobial compounds inhibited the growth of both weakly virulent and virulent R. solani] isolates to the same extent. Four antimicrobial compounds were purified from C. sativa roots and their structures elucidated. Two were identified as the phytoalexins (camalexin and methoxycamalexin) previously described from C. sativa leaves. This appears to be the first report of elicitation of phytoalexins from roots of crucifers. Two preformed antimicrobial compounds were identified as methyl 1-methylindole-3-carboxylate and 10-methyl sulfinyldecylisothiocyanate.

Biologically active phenolic metabolites of a Verticicladiella species

Abstract The metabolites produced when a Verticicladiella species (Canadian Forestry Service strain C728), the causative agent of the black stain root disease of many conifers, is grown in liquid culture have been investigated. Orcinol, orcinol monomethyl ether, 1,3,6,8-tetrahydroxyanthraquinone, and the α- L -rhamnopyranosides of orcinol and orcinol methyl ether have been isolated and identified. Orcinol methyl ether and its rhamnoside both show antibacterial activity and orcinol methyl ether also inhibits the growth of pine germlings. The general antibacterial activity of 5-alkylresorcinols and their monomethyl ethers is reported.