Twelve different seed coat color genotypes of Phaseolus vulgaris L. were extracted and pure flavonoids isolated from 10 of these. The seed coat methanol extracts, tannin fractions, and pure flavonoids all displayed antioxidant activity in a fluorescence-based liposome assay. The relatively high activity of the condensed tannin (proanthocyanidin) fractions indicates that these may play an important role in the overall activity of the extracts. This activity also indicates that although these polyphenols cause problems in digestibility, they may be important dietary supplements with beneficial health effects. The pure anthocyanins delphinidin 3-O-glucoside (1), petunidin 3-O-glucoside (2), and malvidin 3-O-glucoside (3) and the flavonol quercetin 3-O-glucoside (4) isolated from seed coats also had significantly higher antioxidant activity than the Fe(2+) control. The activity of kaempferol 3-O-glucoside (5) was not different from that of the Fe(2+) control. These findings suggest that variously colored dry beans may be an important source of dietary antioxidants.

Proanthocyanidins and flavonoids were isolated and identified from seed coats of two aged and nonaged pinto bean lines: 1533-15 and CDC Pintium. The seed coat of 1533-15 darkens slowly and never darkens to the same extent as CDC Pintium. Analysis of the overall level of proanthocyanidins using a vanillin assay demonstrated that aged and nonaged seed coats of CDC Pintium had significantly higher levels of proanthocyanidins than aged and nonaged 1533-15 seed coats. Aged and nonaged seed coats of both lines were found to contain one main flavonol monomer, kaempferol, and three minor flavonols, kaempferol 3-O-glucoside, kaempferol 3-O-glucosylxylose, and kaempferol 3-O-acetylglucoside. These compounds were identified by NMR and ESI-MS analysis (except for kaempferol 3-O-acetylglucoside, which was tentatively identified only by ESI-MS analysis) and quantified using HPLC-DAD. The combined concentrations of all the kaempferol compounds in seed coats of CDC Pintium were significantly higher than in seed coats of 1533-15, and the combined contents did not change after aging. The content of kaempferol decreased nearly by half in the seed coats of CDC Pintium after aging, whereas no significant change was observed in the seed coats of 1533-15. Proanthocyanidin fractions from both lines, aged and nonaged, were subjected to LC-MS/MS analysis and found to be composed primarily of procyanidins. Procyanidins in the seed coats were predominantly polymers with the degree of polymers higher than 10. The proportion of these polymers decreased after aging, while that of the low-molecular-weight procyanidins increased. A catechin-kaempferol adduct was tentatively identified in both lines by LC-MS/MS, and the concentration increased in the seed coats after aging.

Leaves of Chrysanthemum morifolium cv. Ramat were extracted sequentially with hexane, ethyl acetate, and methanol. The methanol fraction, when incorporated into artificial diet was found to reduce the growth of cabbage looper (Trichoplusia ni Hubner) larvae at concentrations between 500 and 5000 ppm of diet. Fractionation of the methanol extract on a Sephadex column yielded five fractions, three of which reduced the weight of larvae relative to the control. One fraction was analyzed using high performance liquid chromatography (HPLC) and found to contain three main constituents. These compounds were purified using a combination of gel permeation chromatography on Sephadex LH20 and HPLC, and analyzed by 1H and 13CNMR as well as undergoing chemical and physical analyses. The compounds were identified as: 1, chlorogenic acid (5-O-caffeoylquinic acid); 2, 3,5-O-dicaffeoylquinic acid; and 3, 3', 4',5-trihydroxyflavanone7-O-glucuronide (eriodictyol7-O-glucuronide). At concentrations between 100 to 1000 ppm these compounds reduced both growth and photosynthesis of Lemna gibba L. with the order of efficacy being: flavanone > chlorogenic acid > 3,5-O-dicaffeoylquinic acid. Furthermore, when incorporated separately into artificial diet these compounds, at 10 to 1000 ppm, enhanced or reduced growth of the cabbage looper (Trichoplusia ni) and gypsy moth (Lymantria dispar L.).

In the Abstract, compound 1 should be identified as 5,7,4′-trihydroxyflavonol 3-O--D-glucopyranoside. Under Results and Discussion, the C4′ assignments were omitted; they are for kaempferol 3-O--D-glucopyranoside C4′ ) 159.92 ppm and for kaempferol 3-O--Dglucopyranoside-(2f1)--D-xylopyranoside C4′ ) 159.95 ppm. Under Literature Cited, the volume number for Kooiman (1931) is 8.

Three dry bean (Phaseolus vulgaris L.) genotypes differing in seedcoat color, mineral brown (P C D J G B v), yellow brown (P C D J G b v), and pale greenish yellow (P C D J g b v), were analyzed phytochemically. Kaempferol 3-O-β-d-glucoside (astragalin) was isolated and identified by nuclear magnetic resonance spectroscopy from all three genotypes, and was the main flavonoid monomer present. Flavonoid polymers (condensed tannins) were detected by thin layer chromatography, but anthocyanins were not detected in the three genotypes. High pressure liquid chromatography analyses indicated that astragalin was present at similar concentrations in pale greenish yellow and mineral brown genotypes, but was significantly lower in yellow brown. Presently, we do not know the functions of the G and B color genes, although the presence of astragalin in the three genotypes studied indicates these genes do not appear to act in a qualitative manner with regard to astragalin production, but may control the amount of astragalin present. Subtle differences in color between these genotypes may be due to the amount and type of tannins which have secondarily polymerized with phenolics and flavonoid monomers.

Three flavonol glycosides were isolated and identified from the commercial dark red kidney bean (Phaseolus vulgaris L.) cultivar Montcalm. In order of highest to lowest concentration these compounds were 3',4',5,7-tetrahydroxyflavonol 3-O-beta-D-glucopyranosyl (2-->1) O-beta-D-xylopyranoside (compound 1), quercetin 3-O-beta-D-glucopyranoside (compound 2), and kaempferol 3-O-beta-D-glucopyranoside (compound 3). Compound 1 is a flavonol glycoside that has not been reported before in P. vulgaris L. These three flavonol glycosides were yellow compounds that do not contribute to the garnet red color of Montcalm seed coats. Red-colored compounds which tested positive for proanthocyanidins are most likely responsible for the red seed coat color of Montcalm. Previous work on the chemistry of the compounds produced from the multi-allelic seed coat gene series C-C(r)()-c(u) indicated that neither anthocyanins nor flavonol glycosides were detected from seed coat extracts in the presence of the c(u)() locus. However, the seed coat color genotype of Montcalm is c(u) J g B v rk(d) and three flavonol glycosides were found. Technological advances such as modern HPLC analysis of seed coat extracts may allow for detection of small amounts of compounds which previously could not be seen using paper chromatography. Alternatively, the change of the Rk allele to rk(d) may allow for the synthesis of flavonol glycosides in the presence of c(u).

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Two flavonol glycosides were isolated from the methanol extracts of “Prim”, a variety of Phaseolus vulgaris L. (Manteca-type), with a yellow seed coat color. High-performance liquid chromatography was used to isolate and identify compound 1, kaempferol (3,4,5,4‘-tetrahydroxyflavone)-3-O-β-d-glucopyranoside, and compound 2, kaempferol 3-O-β-d-glucopyranoside-(2→1)-O-β-d-xylopyranoside. Concentrations of these compounds were 49.9 ± 0.78 mg/100 g and 58.5 ± 1.67 mg/100 g of fresh whole bean weight, respectively. These two flavonols were the only flavonoids found in Prim and our data indicate that they are responsible for imparting the yellow color to the seed coat. We were not able to indicate the biochemical effects of the eight genes responsible for seed coat color, but we show that G is probably not responsible for producing a flavonol 3,5-diglycoside as has been hypothesized in the literature. No proanthocyanidins (condensed tannins) were found in Prim dry bean seed coat. Keywords: Phaseolus vulgaris L.; flavonol glycosides; seed coat color genotype; proanthocyanidins