Masato Yokoi

FLOWER FLAVONOL AND ANTHOCYANIN DISTRIBUTION IN SUBGENUS ROSA

Abstract In a survey of flower flavonoids in 120 taxa from 10 sections of subgenus Rosa, 19 flavonols and six anthocyanins were detected: six kaempferol (K) glycosides; 3-glucoside (in 99% taxa), 3-rutinoside (63%), 3-sophoroside (60%), 3-rhamnoside (70%), 7-glucoside (94%) and 4′-glucoside (4%); and six quercetin (Q) glycosides: 3-glucoside (91%), 3-glucuronide (62%), 3-rutinoside (63%), 3-sophoroside (69%), 7-glucoside (90%) and 4′-glucoside (4%), and seven unidentified flavonols, and two cyanidin glycosides; 3,5-diglucoside (68%) and 3-glucoside (16%) and two peonidin glycosides; 3,5-diglucoside (41%) and 3-glucoside (4%) and two unidentified anthocyanins. From the flavonoid distribution patterns of this analysis, 120 taxa in the subgenus Rosa were divided into three groups as follows. The first group was characterized by much containing of K and Q 3-glucosides, and the absence of K and Q 4′-glucosides. Fifty-nine taxa from six sections (Gallicanae 32, Chinenses 14, Synstylae 6, Laevigatae 2, Bracteatae 1 and Banksianae 4) were classified into this group. Small amounts of K and Q 3-sophorosides were found in sections Synstylae, Laevigatae and Bracteatae, but they were sporadically present in sections Gallicanae and Chinenses and were absent in sect. Banksianae. In the second group, 55 taxa from three sections (Caninae 21, Carolinae 7 and Rosa 27) were placed. These plants contained large amounts of K and Q 3-sophorosides and anthocyanins in their petals, but they did not contain 4′-glucosides. The last group contained only one section, Pimpinellifoliae (six taxa). This group was unique in containing a large amount of K and Q 4′-glucosides. Rosa hemisphaerica, however, did not contain any flavonol and anthocyanin except a small amount of K 3-glucoside. By multivariate analyses, three chemotaxonomical groups of subgenus Rosa were confirmed, and interrelationship among these groups was discussed.

Acylated cyanidin glycosides in the violet-blue flowers of Ipomoea purpurea

Six acylated cyanidin glycosides were isolated from violet-blue flowers of Ipomoea purpurea. These anthocyanins were all based on cyanidin 3-sophoroside-5-glucoside, acylated with caffeic acid and/or p-coumaric acid. Three anthocyanin structures were elucidated to be cyanidin 3-O(-)[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta -D-glucopyranosyl)-6-O-(trans-4-O-(6-O-(trans-caffeyl)-beta-D-glucopyran osyl) caffeyl)-beta-D-glucopyranoside]-5-O(-)[beta-D-glucopyranoside], cyanidin 3-O(-)[2-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta-D-glucopyrano syl)- 6-O-(trans-caffeyl)-beta-D-glucopyranoside]-5-O(-)[beta-D-glucopyranosid e d and cyanidin 3-O(-)[2-O-(6-O-(trans-caffeyl)-beta-D-glucopyranosyl)-6-O- (trans-caffeyl)-beta-D-glucopyranoside]-5-O(-)[beta-D-glucopyranoside]. These three anthocyanins were present in all 12 violet-blue flower strains as major pigments. The colours of these acylated antocyanins were stabler in neutral solution than their deacyl analogues.

Anthocyanins in flowers of genus Rosa, sections Cinnamomeae (=Rosa), Chinenses, Gallicanae and some modern garden roses.

Forty-four taxa of three sections (Cinnamomeae (=Rosa) 26, Chinenses 8 and Gallicanae 10) and eight modern garden roses in the genus Rosa were surveyed for their floral anthocyanins. Eleven anthocyanins: 3-glucosides and 3,5-diglucosides of cyanidin (Cy), pelargonidin (Pg) and peonidin (Pn), 3-rutinosides and 3-rho-coumaroylglucoside-5-glucosides of Cy and Pn, and Cy 3-sophoroside, were isolated from flowers of these taxa and identified by chemical and spectroscopic techniques. Four anthocyanins: Cy 3-rutinoside, Pn 3-rutinoside, Pn 3-rho-coumaroylglucoside-5-glucoside and Cy 3-sophoroside were found for the first time in Rosa flowers.Investigated sections of wild roses showed characteristic distribution of anthocyanins. Cy 3,5-diglucoside was the dominant anthocyanin detected in all three sections, but accumulation of Pn 3,5-diglucoside distinguished sections Cinnamomeae from other sections, and the occurrence of Cy 3-glucoside separates section Chinenses from others.Cy 3-sophoroside was detected in large amount in some taxa of section Cinnamomeae: e.g., R. moyesii and its related cultivars, and R. rugosa cv. Salmon Pink. The acylated Cy glycoside was found in all sections and also in some modern garden roses, while the acylated Pn glycoside was detected in the section Cinnamomeae, but not in sections Chinenses and Gallicanae. According to anthocyanin distribution patterns, eight groups were classified chemotaxonomically in genus Rosa.

Acylated pelargonidin glycosides in the red-purple flowers of pharbitis nil

Four acylated pelargonidin glycosides and pelargonidin 3-sophoroside-5-glucoside were isolated from 23 red-purple cultivars of Pharbitis nil. The acylated anthocyanins were all based on pelargonidin 3-sophoroside-5-glucoside and were identified as the 3-O-[2-O-(beta-D-glucopyranosyl)-6-O-(trans-caffeyl)-beta-D- glucopyranoside]-5-O-(beta-D-glucopyranoside), the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta- D-glucopyranosyl)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta- D-glucopyranosyl)-6-O-(trans-caffeyl)-beta-D-glucopyranoside]-5-O-(beta- D-glucopyranoside); and the 3-O-[2-O-(6-O-(trans-3-O-(beta-D-glucopyranosyl)caffeyl)-beta-D- glucopyranosyl)-6-O-(trans-4-O-(6-O-(trans-3-O-(beta-D- glucopyranosyl)caffeyl)- beta-D-glucopyranosyl)caffeyl)-beta-D-glucopyranoside]-5-O-(beta-D- glucopyranoside). By the analysis of these anthocyanin constituents variously in 23 cultivars, it was found that the red flower colour gradually changed into more bluish colour with increasing numbers of caffeic acid residues in the acylated pelargonidin glycosides. The stabilities of these anthocyanins increased in the order of increasing caffeyl substitution.

Flavonoids in the acyanic flowers of Pharbitis nil

Abstract In an investigation of the white, cream and pale yellow flowers of 11 acyanic cultivars and 10 acyanic strains of Pharbitis nil, eight flavonoids and six caffeic acid derivatives were detected. From the aqueous methanolic flower extracts five flavonoids were identified: 2′,4,4′,6′-tetrahydroxychalcone, aureusidin 4′-glucoside, R- and S-naringenin 7-glucoside, quercetin 4′- and 7-glucosides, together with chlorogenic acid and caffeic acid. These acyanic cultivars and strains were classified into five groups on the basis of their flavonoid constituents and flower colour. The regulation of anthocyanin biosynthesis in the flowers of P. nil was discussed in relation to the present flavonoid findings.

Distribution of anthocyanins in aceraceae leaves

The distribution of anthocyanins in spring sprouted and/or autumn coloured leaves of Dipteronia sinensis and Acer (119 taxa) was studied. Dipteronia contained four cyanidin glycosides: the 3-glucoside, 3-rutinoside, 3-galloylglucoside and 3,5-diglucoside. Acer contained five cyanidin glycosides: 3-glucoside, 3-rutinoside, 3-galloylglucoside, 3-galloylrutinoside and 3,5-diglucoside, two delphinidin glucosides: 3-glucoside and 3-rutinoside and three unidentified anthocyanins. Both Dipteronia and Acer contained the recently reported cyanidin 3-galloylglucoside. The anthocyanin constituents in spring leaves were more complex than those found in autumn coloured leaves: nine in spring and six in autumn. The presence/absence of the major anthocyanins in the spring sprouted leaves of 111 Acer taxa analysed were grouped into 17 distribution patterns. In the autumn the number of anthocyanin distribution patterns was found to be 11. In Acer, cyanidin glycosides were found in 20 sections and delphinidin glycosides in 17 out of the 21 sections analysed. Although the distribution of anthocyanins showed no clear relations among sections, delphinidin glycosides were mainly found in sections Macrantha, Goniocarpa and Saccharina. There were no differences in the pigment constituents in the species native to different countries, such as A. rubrum in North America and A. pycnanthum in Japan, both containing the same pigments: cyanidin 3-glucoside, 3-rutinoside, 3-galloylglucoside, 3-galloylrutinoside and 3,5-diglucoside.

Acylated cyanidin 3-sambubioside-5-glucosides in Matthiola incana

Four acylated cyanidin 3-sambubioside-5-glucosides were isolated from purple-violet flowers of Matthiola incana and their structures were determined by chemical and spectroscopic methods. Three acylated anthocyanins were cyanidin 3-O-(6-O-acyl-2-O-(2-O-sinapyl-beta-D-xylopyranosyl)-beta-D- glucopyranosides)-5-O-(6-O-malonyl-beta-D-glucopyranosides), in which the acyl group is p-coumaryl, caffeyl or ferulyl, respectively. The remaining pigment is free from malonic acid and was identified as cyanidin 3-O-(6-O-trans-ferulyl-2-O-(2- O-trans-sinapyl-beta-D-xylopyranosyl)-beta-D-glucopyranoside)-5-O- (beta-D-glucopyranoside). Analysis of the anthocyanin constituents in 16 purple-violet cultivars revealed that they contained the above triacylated anthocyanins in variable amounts as main pigments. An aromatic pair of pigments containing sinapic and ferulic acids are considered to produce an important intramolecular effect, making bluish colours in these flowers.

An acylated peonidin glycoside in the violet-blue flowers of Pharbitis nil

Abstract A new acylated anthocyanin was isolated from the violet-blue flowers of Pharbitis nil as a major anthocyanin. The structure of this pigment was determined to be peonidin 3[6″-(4-glucosyl- trans -caffeyl)sophoroside]-5-glucoside. Peonidin 3-sophoroside-5-glucoside was also detected as a minor pigment.

Acylated cyanidin glycosides in the purple-red flowers of Bletilla striata

Abstract Eight acylated anthocyanins were isolated from the purple-red flowers of Bletilla striata as major anthocyanins. These pigments were based on cyanidin 3,7,3′-triglucoside as their deacylanthocyanins, and were acylated with malonic, p-coumaric and caffeic acids and/or glucosylated hydroxycinnamic acids. Four structures were determined by spectral and chemical methods: cyanidin 3-O-[6-O- (malonyl)-β- d -glucopyranoside]-3′ -O-[6-O-(trans-4-O-(6-O-(trans-4-O- (β- d -glucopyranosyl) -p- coumaryl )-β- d -glucopyranosyl) -p- coumaryl )-β- d -glucopyranoside ]-7-O-[6-O-(trans-p- coumaryl )-β- d -glucopyranoside ] ; the demalonyl derivative; cyanidin 3-O-[6-O- (malonyl)-β- d -glucopyranoside ]-3′-O-[6-O-(trans-4-O-(6-O-(trans-4-O- (β- d - glucopyranosyl)-caffeyl)-β- d -glucopyranosyl)-caffeyl)-β- d -glucopyranoside ]-7-O-[6-O-(trans- caffeyl)-β- d -glucopyranoside ]; and the demalonyl derivative.

Light absorption patterns of intact Rosa flowers in relation to the flower colour

Absorption curves of fresh, intact petals from 18 rose cultivars and 2 species were measured and compared with visual evaluations of their colours and there was a reasonable correlation. The in vivo maxima of anthocyanin absorption were in the range of 520–560 nm. Five patterns of absorption spectrum in the visible region were recognized: (a) maximum range ca. 520–535 rim (red roses); (b) as (a) but low absorbance (pink roses); (c) absorption pattern varying with age of flowers; (d) absorption at long wavelengths in blue roses due to co-pigmentation of cyanin, flavonols; (e) absorption of carotenoids and anthocyanins together in yellow, orange or orange red flowers.