Kneubuhl, F. K. Line Shapes of Electron Paramagnetic Resonance Signals produced by powders, glasses, and viscous liquids. J.

Ethanol extract of leaves of Poa ampla, either infected or uninfected with the symbiotic fungus Neotyphodium typhnium, were tested for bioactivity against the mosquito larvae. Results of these tests indicated that only the extracts obtained from endophyte-infected grass are active against mosquito larvae. Relatively high activity was detected in stromata, seeds, spikelets, and leaves of plants, while only weak or no activity was found in extracts of the isolated fungus. The ethyl acetate fraction had approximately the same activity as that of the crude extract, while the activities from 1-butanol and hexane were intermediate and low, respectively. Bioassay-guided fractionation of the ethyl acetate fraction yielded tricin (1), 7-O-(β-d-glucopyranosyl)tricin (2), and isoorientin (3) as the bioactive constitutents. A fourth compound, 7-O-[α-l-rhamnopyranosyl(1−6)−β-d-glucopyranosyl]tricin (4), was also isolated from the active fraction but showed little activity in this assay. Keywords: Poa ampla; turf; endophyte; Neotyphodium typhnium; insecticidal properties; bioactivity; flavonoid; flavonoid−glycoside

Four pyranocoumarins; dipetaline, alloxanthoxyletin, xanthoxyletin and xanthyletin; and two lignans; sesamin and asarinin were isolated from the northern prickly ash, Zanthoxylum americanum. To varying degrees, all inhibited the incorporation of tritiated thymidine into human leukaemia (HL-60) cells. Dipetaline was the most active with an IC(50) of 0.68 ppm, followed by alloxanthoxyletin (1.31 ppm), sesamin (2.71 ppm), asarinin (4.12 ppm), xanthoxyletin (3.48 ppm) and xanthylletin (3.84 ppm).

Zingiberene was detected in foliage extracts of Lycopersicon hirsutum f. hirsutum. 2-Tridecanone was not present in L. hirsutum f. hirsutum but did occur in L. hirsutum f. glabratum. F2's of L. hirsutum f. glabratum X L. hirsutum f. hirsutum segregated for the presence of zingiberene and 2-tridecanone. The occurrence of zingiberene in L. hirsutum f. hirsutum coincided with the sporadic appearance of resistance to Colorado potato beetle (Leptinotarsa decemlineata) in this subspecies. Resistance to Colorado potato beetle in the F2's was correlated with zingiberene content and with 2-tridecanone content. Extracts of L. hirsutum f. hirsutum foliage were toxic to Colorado potato beetle larvae at zingiberene contents estimated at 12-25 gg/larva. Zingiberene content of L. hirsutum f. hirsutum leaflets was estimated to be from 160 to 250 µg/2-cm2 leaflet.