Search Results

You are looking at 81 - 90 of 570 items for :

  • Refine by Access: All x
Clear All
Free access

W.Y.L. Poon and I.L. Goldman

1 Former graduate assistant. We thank Peter Vanderveer for assisrtance with HPLC analyses, Marilyn H.Y. Hovius for assistance with figures, and W.F. Tracy and T. Sharkey for helpful comments.

Free access

V.I. Shattuck, Y. Kakuda, B.J. Shelp, and N. Kakuda

Abbreviations: GS, glucosinolate; HPLC, high-performance liquid chromatography. 1 Dept. of Horticultural Science. 2 Dept. of Food Science. We gratefully acknowledge E.W. Underhill for performing the LC plasma spray mass spectrometry analysis and

Free access

Joshua K. Craver, Joshua R. Gerovac, Roberto G. Lopez, and Dean A. Kopsell

Econofilter PTFE 25/20; Agilent Technologies, Wilmington, DE) using a 5-mL syringe (Becton, Dickinson and Co., Franklin Lakes, NJ) before HPLC analysis. Carotenoid and chlorophyll HPLC analysis. An HPLC unit with a photodiode array detector (1200 series

Free access

Joseph K. Peterson, Howard F. Harrison, and Maurice E. Snook

After removal of the periderm, cortex tissue of the sweetpotato cultivar Regal was collected. Polar extracts of this tissue strongly inhibited germination of proso-millet seed. C18 preparative, step-gradient chromatography (H2O → 100% methanol) gave some 50+ fractions, all of which were assayed for inhibitory properties. Analytical HPLC, using diode array detection and signal processing, showed the presence of chlorogenic, p-coumaric and caffeic acid, scopolin and some unknown phenolic acids. Most fractions were inhibitory to some degree; however, the least polar ones (in 90% and 100% methanol), containing unknown compounds, were most inhibitory. Semi-prep HPLC of these fractions produced eight major peaks (λmax at 210–213 nm, λ2 at 281–284 nm). In our bioassays, the compounds produced 50% inhibition of proso-millet seed germination at ≈60 ppm. It is likely that these compounds contribute significantly to the allelopathic properties of sweetpotato.

Free access

Yuko Yoshizawa, Kenji Sakurai, Satoru Kawaii, Masayoshi Asari, Junichi Soejima, and Noboru Murofushi

Aqueous ethanol extracts prepared from 19 apple (Malus ×domestica Borkh.) cultivars were studied to explore their antiproliferative activity. Half of them showed strong inhibition on proliferation of human leukemic HL-60 cells, while the others were weak. Total polyphenols, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and total anthocyanins were measured and the results indicated that the antiproliferative activity was more strongly correlated to the polyphenols and radical scavenging activity than to the anthocyanin content. Several polyphenols in `Jonathan' were identified and quantified by high-performance liquid chromatography (HPLC) analysis. Among those compounds found during HPLC, catechin and epicatechin seemed partially responsible for HL-60 antiproliferation. A careful examination on parentage of the apple cultivars tested revealed that `Jonathan' and its progeny showed high antiproliferation toward HL-60. This is the first observation about the relationship between antiproliferative activity and parentage of apples, and the information would be useful to create new apple cultivars that posses more anticancer potential.

Free access

M.E. Garcia, C.R. Rom, J.B. Murphy, and G.W. Felton

The leaf phenolic content of 25 Malus species obtained from the National Germplasm Repository was evaluated. Two methods were utilized for determination of phenolic quantity and form. Total dihydroxy phenolic content was determined by spectrophotometric method using diphenlboric acid 2 aminoethyl ester as the reagent. These phenolics were quantified by using HPLC. Differences in phenolic quantity and type among the species were observed. This variation will be discussed in relation to apple–insect interactions.

Free access

Lailiang Cheng and Fengwang Ma

Lisong Chen, Chris Watkins, and Sunita Kochhar for helpful discussions on antioxidant measurements and Rich Raba for technical assistance with HPLC.

Free access

Jan E. Paul Debaene and Laren Robison

Tepary beans (Phaseolus acutifolius A. Gray) are considered drought and heat tolerant, desirable characteristics for arid regions. Knowing the genetic distances among tepary lines can indicate both compatibility for intraspecific crosses and potential for Interspecific P. acutifolius × P. vulgaris hybrids. Fifteen tepary lines, including cultivars and landraces, were compared to two pinto bean varieties using random amplified polymorphic DNA's (RAPDs). At the present time polymorphisms have been clearly identified between wild and cultivated teparies and the pinto bean. An ammo acid profile is also being determined using HPLC. More work needs to be completed before relationships among cultivated teparies can be established.

Free access

Jane E. Lancaster, Julie Farrant, and Martin L. Shaw

1 Scientist; e-mail: jlancaster@xtra.co.nz . 2 Research assistant. Research funded by New Zealand Institute for Research Science and Technology. Statistical assistance of Fred Potter and Ruth Butler and HPLC analytical assistance of Kevin Sutton is

Free access

C.R. Brown, C.G. Edwards, C.-P. Yang, and B.B. Dean

and technical support for the HPLC analysis of these materials. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to