Search Results
Abstract
High-performance liquid chromatographic (HPLC) procedures for the separation of flavonoids in poinsettia bracts are described. Anthocyanins present were cyanidin 3-galactoside, and the 3-glucosides and 3-rutinosides of cyanidin and pelargonidin. Flavonols present were 3-rhamnosylgalactosides, 3-rhamnosylgluco-sides, 3-galactosides, 3-glucosides, and 3-rhamnosides of quercetin and kaempferol. The use of these chemical markers along with the classical methods for plant identification should help resolve the difficulties of describing new cultivars protected by the plant patent law.
Abstract
Flavonoids in flowers of ‘White Masterpiece’, ‘Bridal Pink’, and ‘Samantha’ roses (Rosa spp) were either kaempferol or quercetin 3-glycosides. They were the glucoside, xyloside, arabinoside, rhamnoside, glucuronide, rutinoside, a rhamnosylglucoside (not rutinose or neohesperidose), an acylated form of the rhamnosylglucoside, and galloylghicoside. Kaempferol 4’-glucoside, an important marker derived almost exclusively from old Scotch roses (R. foetida and R. spinossisima) was present only in ‘White Masterpiece’. Anthocyanins from ‘Bridal Pink’ and ‘Samantha’ were either cyanidin or pelargonidin 3,5-diglucosides along with traces of the related 3-glucoside. Parameters for the resolution and the quantitation of these flavanoids, by high pressure liquid chromatography, were established. Uniform sampling techniques were developed because of the quantitative differences in the flavonoid distribution in a rose petal. Changes in the rate of fertilizer application and daylength affected only the concentration of the flavonoids, and the ratio of each compound to the total remained fairly constant.
Abstract
High pressure liquid chromatographic (HPLC) procedures were developed for the resolution and quantitation of naturally occurring flavonoids in florets of geranium (Pelargonium X hortorum Bailey). Anthocyanins identified were the 3,5-diglucosides of cyanidin, pelargonidin, peonidin, malvidin, delphinidin, and petunidin. Related flavonoid copigments were: the 3-glucoside, 3-galactoside, 3-xyloside, 3-arabinopyranoside, 3-arabinofuranoside, 3-rutinoside, 3-rhamnosylgalactoside, and 7-glucoside of kaempferol and the 3-glucoside, 3-galactoside, 3-rhamnoside, 3-rutinoside, and 3-rhamnosylgalactoside of quercetin. Significant qualitative and quantitative differences between the 20 flavonoid chemical markers distinguished all but 2 of the 20 cultivars examined. It is believed that the 2 indistinguishable cultivars arose as sports from the same cultivar and are genetically identical for floral pigmentation.
Abstract
Flavonoids isolated from ‘Better Times’ rose petals were cyanidin 3,5-diglucoside, the 3-rhamnoside, 3-glucoside, 3-arabinoside, 3-glucuronide of quercetin and the 3-glucoside, and 3-xyloside of kaempferol. The rose pigment, a co-pigment complex of cyanindin 3,5-diglucoside (2.0-2.8 × 10-2M) and quercetin or kaempferol glycosides, (0.8-1.4 × 10-1M, expressed as quercitrin) was present only in epidermal cells. At the pH of freshly harvested tissue (3.70 to 4.15) this pigment was red with a λmax of 539 nm. As the tissue aged the pH increased (4.40 to 4.50) and the pigment became more blue with a λmax of 543 nm. Cornell preservative prevented the increase in pH of commercial cut roses and maintained their original color. The high pigment concn and the phenomenon of co-pigmentation explain the intense color of ‘Better Times’ roses in a pH range where anthocyanins alone are virtually colorless.
Abstract
The anthocyanin isolated from flowers of Limonium cvs. Twilight Lavender and Midnight Blue was delphinidin 3,5-diglucoside, and that from ‘Blue Bonneť and ‘American Beauty’ was delphinidin 3-glucoside. The major flavonoid co-pigments in all 4 cvs. were luteolin and its 6-C-glucoside (iso-orientin). These co-pigments were also present in white ‘Iceberg’ and yellow ‘Gold Coast’. The range of colors from reddish-purple to blue for the various cvs. was directly related to the pH of the tissue.