Dwight D. Baker

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Natural products have provided considerable value to the pharmaceutical industry over the past half century. In particular, the therapeutic areas of infectious diseases and oncology have benefited from numerous drug classes derived from natural product sources. Unfortunately, pharmaceutical companies have significantly decreased activities in natural(More)
Cross-inoculation studies of numerous Frankia strains of Asian origin, primarily Chinese, were undertaken to determine whether previously described host specificity groups (HSG) were valid. Each strain was inoculated onto seedlings of Alnus glutinosa, Casuarina cunninghamiana, Elaeagnus angustifolia and Myrica cerifera in solution culture, and the presence(More)
Six methods for the estimation of microbial biomass were compared for determination ofFrankia cell concentrations. Six strains ofFrankia were cultivated in stationary culture, harvested by centrifugation, washed with saline buffer and diluted to five standardized concentrations. These cell suspensions were then used to assess reliability of each of the(More)
The response ofAlnus glutinosa, Casuarina cunninghamiana, Elaeagnus angustifolia andMyrica cerifera to a range of substrate nitrogen levels in solution, in relation to plant growth, infection, nodulation and root fine structure was studied. Nine concentrations of potassium nitrate ranging from 0.05 to 3.0 mM, were tested on each of the species. Plants were(More)
Experiments were conducted to determine the effect on biological dinitrogen fixation byCasuarina of available nitrogen (N) in the substrate and competition by interplantedEucalyptus. In these experiments, combined N was applied to the plants after nodules were developed and functioning. Both environmental factors, nitrate and competition, were observed to(More)
A wide variety of novel small-molecule natural products has recently been reported. These compounds were isolated from marine and terrestrial sources, and from a variety of animals, plants and microorganisms. With the breadth of diversity represented in these bioactive small molecules, the future of natural product drug discovery looks bright.
A correlated light and electron microscopic study was undertaken of the initiation and development of root nodules of the actinorhizal tree species,Elaeagnus angustifolia L. (Elaeagnaceae). Two pure culturedFrankia strains were used for inoculation of plants in either standing water culture or axenic tube cultures. Unlike the well known root hair infection(More)
The extent of transfer of fixed N between N2-fixing and non-N2-fixing plant species is largely unknown in successional studies. In order to redress this deficiency at a locale intensively studied ecologically, leaf tissue samples were collected from actinorhizal N2-fixing (Alnus, Shepherdia, and Dryas) and two non-N2-fixing (Salix) woody species within(More)
A morphological analysis of the initiation and development of root nodules ofElaeagnus angustifolia andMyrica cerifera inoculated with pure-culturedFrankia strains DDB 011610 or DDB 020110 was undertaken. From ultrastructural observations it was determined that both of theseFrankia strains can infectElaeagnus by an intercellular penetration mechanism(More)
Two new trichothecenes, 14'-hydroxymytoxin B (1) and 16-hydroxyroridin E (3), were isolated from a fermentation extract of Myrothecium roridum. The structures of 1 and 3 were determined by spectral data interpretation. Both compounds showed potent cytotoxic activity against primary soft-tissue sarcoma cells.