Cyanidin glycosides in flowers of genus Corydalis (Fumariaceae)

Nine taxa of Corydalis were surveyed for their floral anthocyanins. Five cyanidin glycosides: cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3-rutinoside, cyanidin 3-(2^G-xylosylrutinoside) and cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside were isolated from these taxa and identified by chemical and spectroscopic techniques. A novel anthocyanin was found in the flowers of Corydalis elata and Corydalis flexuosa cultivars, and identified to be cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside. Two anthocyanins, cyanidin 3-sambubioside and cyanidin 3-(2^G-xylosylrutinoside), were also found for the first time in Corydalis flowers. Furthermore, the major anthocyanin constituent of the flowers was cyanidin 3-sambubioside in the outer petals of Corydalis ambigua and Corydalis lineariloba, and cyanidin 3-rutinoside in those of Corydalis decumbens, Corydalis curvicalcarata and Corydalis speciosa. Similarly, Corydalis incisa contained cyanidin 3-(2^G-xylosylrutinoside), and C. flexuosa ‘China Blue’ and ‘Blue Panda’, and C. elata contained the most complex structural pigment, cyanidin 3-(2^G-xylosylrutinoside)-7-glucoside, as their dominant anthocyanin in their outer petals. According to the results of anthocyanin analyses, these nine plants were classified into four groups: groups A (three taxa), B (two taxa), C (one taxa) and D (three taxa). On the other hand, the anthocyanin constituent of their inner petals was composed of cyanidin 3-rutinoside as only one dominant anthocyanin.     

山樱花品种间花色差异的代谢组学研究

山樱花是世界著名的观花类植物，花色是其最重要的观赏特征。为探究影响山樱花品种间花色差异的代谢通路及关键代谢产物变化，该文利用LC-MS/MS技术对白色、绿色和粉色的山樱花品种进行花青素靶向代谢组学比较分析。结果表明：(1)共检测到42种花青素物质，主要包含矮牵牛素、飞燕草素、黄酮类化合物、锦葵色素、芍药花素、矢车菊素、天竺葵素和原花青素8种物质。(2)差异代谢花青素25种，包括11种下调、14种上调，其中有7种花青素在粉色花瓣中显著富集。(3)KEGG通路注释发现差异代谢物在花青素生物合成通路中显著富集，结合聚类结果发现矮牵牛素-3-O-葡萄糖苷是山樱花品种间花色差异产生的关键代谢物。该研究揭示了山樱花花色差异的代谢机理，为后续山樱花花色分子调控机制研究提供了一定的理论依据，也为新品种花色改良和选育提供了一定的科学参考。     

High pressure liquid chromatographic analysis of flavonoid chemical markers in petals from Gerbera flowers as an adjunct for cultivar and germplasm identification

Flavonoids present in petals from Gerbera flowers were resolved and quantitated by high pressure liquid chromatography (HPLC). The anthocyanins isolated from 18 cultivars, ranging in color from orange through lavender, were pelargonidin and cyanidin 3-malonylglucosides accompanied by smaller amounts of pelargonidin and cyanidin 3-glucosides. Related flavonoid copigments were apigenin and luteolin 4′-glucosides and 7-glucosides, apigenin 7-malonylglucoside, kaempferol and quercetin 3-glucosides, 4′-glucosides and 3-malonylglucosides. Both qualitative and quantitative differences in these flavonoid chemical markers distinguished cultivars with very similar colors. Malonyl esters of anthocyanins are easily degraded by HCl and conventional extraction and purification procedures were adjusted to preserve their natural state.     

Daminozide Alters Anthocyanin Metabolism in Ray Florets of Bronze Chrysanthemum (Chrysanthemum morifolium Ramat.)

Daminozide is a well-known chemical inhibitor of the gibberellic acid biosynthesis pathway regulating the vegetative growth of potted chrysanthemums (Chrysanthemum morifolium Ramat.). However, the precise mechanism underlying daminozide-related floral color loss is unknown. To investigate the latter, in two separate greenhouse experiments, bronze flowering chrysanthemum cultivars ‘Baton Rouge’ and ‘Pelee’ were treated weekly with consecutive (0 or 5,000 mg l^?1) foliar daminozide spray applications at early, intermediate, and late stages during the short-day photoperiod. The ray florets of both cultivars were sampled, and the effect of daminozide application on anthocyanins and their biosynthetic precursors were determined by HPLC. Daminozide applied to ‘Baton Rouge’ plants at early developmental stages was correlated with partial loss of red color, and HPLC analysis determined that this was associated with a 75 % reduction in ray floret anthocyanins. Conversely, a near complete loss of red coloration in daminozide-sprayed ‘Pelee’ relative to control plants was associated with as much as a 98 % decline in anthocyanins, irrespective of the time of application. HPLC analysis determined that daminozide application was associated with a 22–50 % increase in the flavones apigenin 7-O-rutinoside, acacetin 7-O-rutinoside, diosmetin 7-O-rutinoside, and eupatorin, and a 68 % increase in the flavonol quercetin 3-O-glucoside, in ray florets of ‘Pelee’ relative to control plants. There was no relative change in ‘Baton Rouge’ flavone and flavonol levels. The accumulation of bronze C. morifolium flavones and flavonols following foliar daminozide application suggests that red color loss is associated with inhibition of anthocyanidin synthase of ‘Pelee’ ray florets.     

Flavonoids from the flowers of Adenium obesum (Forssk.) Roem. & Schult., Mandevilla sanderi (Hemsl.) Woodson,and Nerium oleander L. (Apocynaceae)

Twenty-two ornamental flowers from different Adenium obesum, Mandevilla sanderi, and Nerium oleander cultivars/seedlings were analyzed for the presence of anthocyanins, flavonols, and chlorogenic acid using nuclear magnetic resonance (NMR) and mass spectrometry (MS). Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major and minor anthocyanins, respectively, in three A. obesum seedlings that had red and red-purple flowers.Cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the major anthocyanin, whereas cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the minor anthocyanins in 8 M. sanderi cultivars that had red and red-purple flowers. Cyanidin 3-O-[6-O-(rhamnosyl)-galactoside] and cyanidin 3-O-(galactoside) were identified as the major anthocyanins, whereas cyanidin 3-O-[2-O-(xylosyl)-galactoside] was identified as the minor anthocyanin in 8 N. oleander cultivars with red and red-purple flowers. Low levels of anthocyanins were detected in the N. oleander and M. sanderi cultivars that had white flowers, and there were no anthocyanins detected in the N. oleander cultivars with yellow flowers. Chlorogenic acid and four flavonols, quercetin 3-O-[6-O-(rhamnosyl)-galactoside], quercetin 3-O-[6-O-(rhamnosyl)-glucoside], kaempferol 3-O-(galactoside), and kaempferol 3-O-[6-O-(rhamnosyl)-galactoside], were identified in the flowers from all 22 cultivars/seedlings investigated.     

Comparative analysis of quality and nutritional traits from Lonicera caerulea (Honeyberry) cultivars and other berries grown in Scotland

Lonicera caeruleabrix is a perennial shrub native to North America, Europe and Asia. It produces dark blue berries known as honeyberries or haskap berries which are produced commercially in several territories including Canada, Japan, Russia and Poland. Plants are suited to UK environments, but it is yet to be widely commercially developed in the UK. In the present work, quality and nutritional traits of six honeyberry cultivars grown in Scotland were compared with other commonly grown berry fruits (strawberry, raspberry, blueberry, blackberry, blackcurrant) to aid the identification of environmentally stable, high-quality honeyberry cultivars suitable for UK cultivation. Differences were observed in fruit quality variables (soluble solids, titratable acidity and Brix/acid ratios) between honeyberry cultivars. Three of six cultivars examined exhibited notable variation in soluble solids dependent on harvest year with ‘Aurora’ and ‘Strawberry Sensation’ having consistently high ^oBrix values. Titratable acidity exhibited cultivar differences and there was limited variation over harvest years. ‘Aurora’ exhibited consistently high ^oBrix/titratable acidity ratio reflected by high glucose and fructose content. Honeyberry fruit had good nutritional profile relative to other soft fruits with higher polyphenol and anthocyanin content than strawberry, blueberry, blackberry and raspberry, manifested in greater antioxidant capacity. The major anthocyanins in aqueous honeyberry fruit extracts were cyanidin, pelargonidin and peonidin glycosides. These findings indicate that L. caerulea represents a crop suitable for UK cultivation capable of producing high quality fruit with a valuable nutritional profile relative to other soft fruits. Cultivars exhibit significant differences in fruit quality and nutritional profile as well as harvest consistency and growers should consider this when establishing new plantations.     

A further survey of anthocyanins and other phenolics in Ilex and Euonymus

A survey of 27 plants of Ilex and Euonymus revealed that the distribution of anthocyanins and cinnamic acid esters in their fruits is correlated with accepted taxonomic classification. In the skin of the fruit, the 3-xylosylglucoside of cyanidin and pelargonidin and the 3-monoglucoside of cyanidin were identified, and the hydrolysed fruit-extracts were found to contain quercetin, kaempferol and caffeic acid. The genus Ilex has been shown to be distinguishable from the genus Euonymus by their anthocyanins; I. micrococca was exceptional in having only chrysanthemin. Additionally, chlorogenic and isochlorogenic acids and caffeylglucose occur in Ilex but not in Euonymus. The microspectrophotometric examination of the pigment cells of the black- and red-Ilex fruits revealed that the position of absorption maxima in the visible region is mainly related to the relative amounts of anthocyanin and flavonol present.     

Anthocyanins in the epacridaceae

An examination of 73 species of the family Epacridaceae resulted in the identification of the following anthocyanins: cyanidin 3-galactoside, cyanidin 3-glucoside, cyanidin 3-arabinoside, cyanidin 3-rhamnoside, cyanidin 3-rhamnosylgalactoside, cyanidin 3-rhamnosylglucoside, cyanidin 3-xylosylgalactoside, cyanidin 3-xylosylarabinoside, delphinidin 3-galactoside, delphinidin 3-arabinoside, delphinidin 3-rhamnosylgalactoside, delphinidin 3-rhamnosylglucoside and pelargonidin 3-rhamnosylglucoside. No acylated or 5-substituted anthocyanins were detected in any of the species examined. Evidence of methylated anthocyanidin was found only in one species, Woollsia pungens. The occurrence of cyanidin 3-galactoside and cyanidin 3-arabinoside forms a chemical link between this family and the related Ericaceae.     

High-yield anthocyanin biosynthesis in engineered Escherichia coli

Anthocyanins are red, purple, or blue plant water-soluble pigments. In the past two decades, anthocyanins have received extensive studies for their anti-oxidative, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, and cardioprotective properties. In the present study, anthocyanin biosynthetic enzymes from different plant species were characterized and employed for pathway construction leading from inexpensive precursors such as flavanones and flavan-3-ols to anthocyanins in Escherichia coli. The recombinant E. coli cells successfully achieved milligram level production of two anthocyanins, pelargonidin 3-O-glucoside (0.98 mg/L) and cyanidin 3-O-gluside (2.07 mg/L) from their respective flavanone precursors naringenin and eriodictyol. Cyanidin 3-O-glucoside was produced at even higher yields (16.1 mg/L) from its flavan-3-ol, (+)-catechin precursor. Further studies demonstrated that availability of the glucosyl donor, UDP-glucose, was the key metabolic limitation, while product instability at normal pH was also identified as a barrier for production improvement. Therefore, various optimization strategies were employed for enhancing the homogenous synthesis of UDP-glucose in the host cells while at the same time stabilizing the final anthocyanin product. Such optimizations included culture medium pH adjustment, the creation of fusion proteins and the rational manipulation of E. coli metabolic network for improving the intracellular UDP-glucose metabolic pool. As a result, production of pelargonidin 3-O-glucoside at 78.9 mg/L and cyanidin 3-O-glucoside at 70.7 mg/L was achieved from their precursor flavan-3-ols without supplementation with extracellular UDP-glucose. These results demonstrate the efficient production of the core anthocyanins for the first time and open the possibility for their commercialization for pharmaceutical and nutraceutical applications.     

Identification and distribution of malonated anthocyanins in plants of the compositae

A survey of 31 species from 28 genera in the Compositae showed the presence of zwitterionic anthocyanins in petals or stems of 27 species. Detailed investigations, including the use of FAB-MS, showed that mono- and dimalonated esters of pelargonin and cyanin occurred in Dahlia variabilis cultivars. The corresponding delphin mono- and dimalonates occur in blue flowers Cichorium intybus. A cyanidin 3-dimalonylglucoside was identified in stems of Coleostephus myconis while pelargonidin 3-(6″-malonylg]ucoside) was found in Callistephus petals. A further malonated cyanidin derivative in flowers of Helenium cv. Bruno was found to be the 3-glucuronosylglucoside; this is the first report of an anthocyanin with glucuronic acid. Overall, the results confirm that malonated anthocyanins are widespread in the family and that many pigments previously reported in the Compositae as being unacylated probably contain these labile organic acid attachments.     

Differential gene expression analysis of ‘Granny Smith’ apple (Malus domestica Borkh.) during fruit skin coloration

‘Granny Smith’ apples growing under normal sunlight develop green skin, whereas the peel turns red due to anthocyanin accumulation after the removal of a bagging treatment. Two anthocyanins, Cyanidin 3-O-galactoside (cy3-gal) and Cyanidin 3-O-arabinoside (cy3-ara), were detected in the red ‘Granny Smith’ apple peels, and cy3-gal was determined to be chiefly responsible for the red color. The content of cy3-gal was more than 98% of the total anthocyanin in the red ‘Granny Smith’ peels. To better understand the molecular basis of anthocyanin biosynthesis in ‘Granny Smith’ apples, we performed a quantitative real-time PCR (qRT-PCR) analysis of anthocyanin biosynthetic genes (MdCHS, MdF3H, MdDFR, MdANS, MdUFGT, and MdMYB1). Our results indicate that the expression of these genes (except MdCHS) was associated with increased anthocyanin accumulation in the skin of ‘Granny Smith’ apples. Four selected genes obtained from the ‘Granny Smith’ skin cDNA library, phytoene synthase (PSY), WD40 repeat protein, polygalacturonase (PG), and galactosidase (GAL), were also confirmed by qRT-PCR. We found that these genes were differently expressed during ‘Granny Smith’ apple skin coloration, suggesting that they are directly or indirectly involved in pigment accumulation. In conclusion, anthocyanin biosynthesis in ‘Granny Smith’ apples is the result of interactions between multiple enzymes in the anthocyanin biosynthesis pathway, and the coloring mechanism of ‘Granny Smith’ apples may be similar to that of red-skinned cultivars.     

Flower color diversity revealed by differential expression of flavonoid biosynthetic genes and flavonoid accumulation in herbaceous peony (Paeonia lactiflora Pall.)

Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental plant which contains different flower colors. In this paper, eight genes encoding phenylalanine ammonialyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), UDP-glucose: flavonoid 3-o-glucosyltransferase (UF3GT) were isolated. Moreover, the expression patterns of these eight genes and UF5GT in the flowers were investigated in three cultivars, that is, ‘Hongyanzhenghui’, ‘Yulouhongxing’ and ‘Huangjinlun’ with purplish-red, white and yellow flower respectively. Furthermore, flavonoid accumulation in the flowers was also analyzed. The results showed that in different organs, most of genes expressed higher in flowers than in other organs. During the development of flowers, all genes could be divided into four groups. The first group (PlPAL) was highly expressed in S1 and S4. The second group (PlCHS and PlCHI) was at a high expression level throughout the whole developmental stages. The third group (PlF3H, PlF3′H, PlDFR, PlANS and PlUF5GT) gradually decreased with the development of flowers. The fourth group (PlUF3GT) gradually increased during the flower development. In addition, anthoxanthins and anthocyanins were detected in ‘Hongyanzhenghui’ and ‘Yulouhongxing’, chalcones and anthoxanthins were found in ‘Huangjinlun’. When different color flowers were concerned, low expression level of PlCHI induced most of the substrate accumulation in the form of chalcones and displaying yellow, changing a small part of substrates to anthoxanthins, and there was no anthocyanin synthesis in ‘Huangjinlun’ because of low expression level of DFR. In ‘Yulouhongxing’, massive expressions of upstream genes and low expression of DFR caused synthesis of a great deal of anthoxanthins and a small amount of colorless anthocyanins. In ‘Hongyanzhenghui’, a large number of colored anthocyanins were changed from anthoxanthins because of PlDFR, PlANS and PlUF3GT high expressions. These results would provide us a theoretical basis to understand the formation of P. lactiflora flower colors.     

Acylated anthocyanins and flavonols from purple flowers of Dendrobium cv. ‘Pompadour’

Two rare anthocyanins, cyanidin 3-(6-malonylglucoside)-7,3′-di(6-sinapylglucoside) and the demalonyl derivative, were characterised as the purple floral pigments of Dendrobium cv. ‘Pompadour’. Nine known flavonol glycosides were also identified, including the 3-rutinoside-7-glucosides of kaempferol and quercetin. One new glycoside was detected: the ferulyl ester of quercetin 7-rutinoside-7-glucoside. These flavonoid patterns are typical for plants in the family Orchidaceae.     

The expression level of anthocyanidin synthase determines the anthocyanin content of crabapple (<Emphasis Type="Italic">Malus</Emphasis> sp.) petals

In addition to contributing to the coloration of plant organs and their defense against herbivores, the consumption of anthocyanins in the human diet has a number of health benefits. Crabapple (Malus sp.) represents a valuable experimental model system to research the mechanisms and regulation of anthocyanin accumulation, in part due to the often vivid and varied petal and leaf coloration that is exhibited by various cultivars. The enzyme anthocyanidin synthase (ANS) plays a pivotal role in anthocyanin biosynthesis; however, the relationship between ANS expression and petal pigmentation has yet to be established in crabapple. To illuminate the mechanism of anthocyanin accumulation in crabapple petals, we evaluated the expression of two crabapple ANS allelic genes (McANS-1 and McANS-2) and the levels of anthocyanins in petals from cultivars with dark red (‘Royalty’) and white (‘Flame’) petals, as well as another (‘Radiant’) whose petals have an intermediate pink color. We determined that the expression of McANS in the three cultivars correlated with the variation of anthocyanin accumulation during different petal developmental stages. Furthermore, transgenic tobacco plants constitutively overexpressing one of the two McANS genes, McANS-1, had showed elevated anthocyanin accumulation and a deeper red coloration in their petals than those from untransformed control lines. In conclusion, we propose that McANS are responsible for anthocyanin accumulation during petal coloration in different crabapple cultivars.     

Phase change modifies anthocyanin synthesis in Acer palmatum Thunb. (Japanese maple) cultivars

The potential markers of juvenility (cyanidin 3-glucoside and cyanidin 3-rutinoside) in autumn leaves of seven Acer palmatum Thunb. cultivars were investigated. Three shoot positions were marked on each cultivar—crown shoot, middle shoot, and basal shoot—and the anthocyanins were analyzed using HPLC-MS. The results showed great differences in cyanidin 3-glucoside and cyanidin 3-rutinoside concentrations among seven cultivars; moreover, significant differences in cyanidin 3-glucoside content levels were also observed among three shoot positions regardless of the cultivar analyzed. The concentration decreased basipetally and reached levels up to 52 times higher in leaves obtained from crown shoots in comparison to basal shoot leaves. Therefore, the content level of cyanidin 3-glucoside can be defined as a quantitative marker of positional effect in all the Acer palmatum Thunb. cultivars analyzed. The content level of cyanidin 3-rutinoside did not express the same positional dependence.     

Photoprotection by foliar anthocyanins mitigates effects of boron toxicity in sweet basil (Ocimum basilicum)

Boron (B) toxicity is an important agricultural problem in arid environments. Excess edaphic B compromises photosynthetic efficiency, limits growth and reduces crop yield. However, some purple-leafed cultivars of sweet basil (Ocimum basilicum) exhibit greater tolerance to high B concentrations than do green-leafed cultivars. We hypothesised that foliar anthocyanins protect basil leaf mesophyll from photo-oxidative stress when chloroplast function is compromised by B toxicity. Purple-leafed ‘Red Rubin’ and green-leafed ‘Tigullio’ cultivars, grown with high or negligible edaphic B, were given a photoinhibitory light treatment. Possible effects of photoabatement by anthocyanins were simulated by superimposing a purple polycarbonate filter on the green leaves. An ameliorative effect of light filtering on photosynthetic quantum yield and on photo-oxidative load was observed in B-stressed plants. In addition, when green protoplasts from both cultivars were treated with B and illuminated through a screen of anthocyanic protoplasts or a polycarbonate film which approximated cyanidin-3-O-glucoside optical properties, the degree of photoinhibition, hydrogen peroxide production, and malondialdehyde content were reduced. The data provide evidence that anthocyanins exert a photoprotective role in purple-leafed basil mesophyll cells, thereby contributing to improved tolerance to high B concentrations.     

Determination of anthocyanins and exploration of relationship between their composition and petal coloration in crape myrtle (Lagerstroemia hybrid)

Petal coloration and pigment components in 12 American crape myrtle cultivars (Lagerstroemla indica x Lagerstroemla fauriei) and five Chinese crape myrtle cultivars (L. indica hybrids) were studied. Color was measured by ClEL'a'b" scale and anthocyanin composition of crape myrtle was determined using high-performance liquid chromatography coupled to photodiode array detection and electrospray ionization mass spectrometry. The presence of the previously reported delphinidin 3-O-glucoside, petunidin 3-O-glucoside and malvidin 3-O-glucoside were confirmed. Cyanidin 3-O-glucoside was identified in crape myrtle for the first time. We explored the relationship between petal color and anthocyanin contents by multiple linear regression analyses. The results indicated that total flavones and flavonols were important variables and contributed to blue-enhancing in crape myrtle. Based on anthocyanins and co-pigments analysis, flower color breeding in crape myrtle towards true-red and blue were discussed.