The methanolic extract from aerial parts of Parthenium argentatum, afforded argentatin A and B. These compounds were evaluated for their effect on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as positive control. When tested for activity, using neonate larvae into the no-choice artificial diet bioassays, argentatin A, arg...

Argentatin B is a naturally occurring tetracyclic triterpene isolated from Parthenium argentatum x P. tomentosa. It was microbiologically transformed to 16, 24-epoxycycloartan-3alpha, 25-diol, (isoargentatin D), by Nocardia corallina var. taoka ATCC 31338, Mycobacterium species NRRL B3683 and Septomyxa affinis ATCC 6737. The later microbe also produced 16, 24-epoxycycloartan-3beta, 25-diol (arg...

Oxylipins are oxygenated derivatives of fatty acids and pivotal signaling molecules in plants and animals. Allene oxide synthase (AOS) is a key cytochrome P450 CYP74 enzyme involved in the biosynthesis of plant oxylipin jasmonates to convert 13(S)-hydroperoxide to allene oxide. Guayule (Parthenium argentatum) AOS, CYP74A2, was expressed in Escherichia coli. Protein was purified using affinity c...

Guayule (Parthenium argentatum Gray) is a perennial desert shrub currently under investigation as viable commercial alternative to the Pará rubber tree (Hevea brasiliensis), traditional source of natural rubber. Previous studies on guayule have shown close association between morphological traits or biomass and content. We collected multispectral RGB-derived Structure-from-motion (SfM) data usi...

Guayule seedlinos were received fromi the federal nursery of the Emergency Guayule Project at various times of the year for use in a general study of the growth of this species under greenhouse conditions (1). Stock removed from the nursery at different times of the year showed markedly different powers of regenerationi when transplanted to soil in the greenhouse. The best growth was obtained f...