Characterization of anthocyanins in the hybrid progenies derived from Iris dichotoma and I. domestica by HPLC-DAD-ESI/MS analysis

Combinatorial preparation and structural characterization of anthocyanins and aglycones from Purple-heart Radish for evaluation of physicochemical stability and pancreatic lipase inhibitory activity

In this study, an efficient approach to preparation of different anthocyanins from Purple-heart Radish was developed by combining microwave-assisted extraction (MAE), macroporous resin purification (MRP) and ultrasound-assisted acid hydrolysis (UAAH) for evaluation of physicochemical stability and pancreatic lipase (PL) inhibitory activity. By optimization of MAE, MRP and UAAH processes, the anthocyanins reached the yield of 6.081 ± 0.106 mg/g, the purity of 78.54 ± 0.62 % (w/w) and the content of 76.29 ± 1.31 % (w/w), respectively. With high-resolution UHPLC-Q-Orbitrap/MS, 15 anthocyanins were identified as pelargonins with diverse glucosides and confirmed by pelargonidin standard. By glycosylation, pelargonins exhibited higher stability in different pH, temperature, light, metal ions environments than that of pelargonidin. However, PL inhibitory assay, kinetic analysis and molecular docking demonstrated that pelargonidin had higher PL inhibitory activity than pelargonins even though with similar binding sites and a dose-effect relationship. The above results revealed that the effect of glycosylation and deglycosylation on PL inhibitory activity and physicochemical stability.

Metabolic Patterns of Flavonoid and Its Key Gene Expression Characteristics of Five Cultivars of Tulipa gesneriana during Flower Development

Flower color is one of the most important ornamental traits of tulips (Tulipa gesneriana). Five typical tulip cultivars were selected to identify the flavonoid components and analyze their key gene expression in their tepals. Firstly, after preliminary determination of the pigment type, the flavonoids were identified by UPLC-Q-TOF-MS. A total of 17 anthoxanthins were detected in the five cultivars. The total anthoxanthin content in the white tulip and the red tulip showed a similar decreasing trend, while an increasing trend was observed in the black tulip. Similarly, a total of 13 anthocyanins were detected in five tulip cultivars. The black tulip contained the largest number of anthocyanins, mainly delphinidin derivatives (Dp) and cyanidin derivatives (Cy). The total anthocyanin content (TAC) in the orange, red, and black cultivars was higher than that in the white and yellow cultivars and presented an overall increase trend along with the flower development. TgCHS, TgFLS, TgF3H, TgF3'H, TgF3'5'H, and TgDFR, as key structural genes, were involved in the flavonoid synthesis pathway, and the expression patterns of these genes are basically consistent with the components and accumulation patterns of flavonoids mentioned above. Taken together, the flower color in tulips was closely related to the composition and content of anthocyanins and anthoxanthins, which were indeed regulated by certain key structural genes in the flavonoid pathway.

Association Analysis of Transcriptome and Targeted Metabolites Identifies Key Genes Involved in Iris germanica Anthocyanin Biosynthesis

The anthocyanin biosynthetic pathway is the main pathway regulating floral coloration in Iris germanica, a well-known ornamental plant. We investigated the transcriptome profiles and targeted metabolites to elucidate the relationship between genes and metabolites in anthocyanin biosynthesis in the bitone flower cultivar 'Clarence', which has a deep blue outer perianth and nearly white inner perianth. In this study, delphinidin-, pelargonidin-, and cyanidin-based anthocyanins were detected in the flowers. The content of delphinidin-based anthocyanins increased with the development of the flower. At full bloom (stage 3), delphinidin-based anthocyanins accounted for most of the total anthocyanin metabolites, whereas the content of pelargonidin- and cyanidin-based anthocyanins was relatively low. Based on functional annotations, a number of novel genes in the anthocyanin pathway were identified, which included early biosynthetic genes IgCHS, IgCHI, and IgF3H and late biosynthetic genes Ig F3'5'H, IgANS, and IgDFR. The expression of key structural genes encoding enzymes, such as IgF3H, Ig F3'5'H, IgANS, and IgDFR, was significantly upregulated in the outer perianth compared to the inner perianth. In addition, most structural genes exhibited their highest expression at the half-color stage rather than at the full-bloom stage, which indicates that these genes function ahead of anthocyanins synthesis. Moreover, transcription factors (TFs) of plant R2R3-myeloblastosis (R2R3-MYB) related to the regulation of anthocyanin biosynthesis were identified. Among 56 R2R3-MYB genes, 2 members belonged to subgroup 4, with them regulating the expression of late biosynthetic genes in the anthocyanin biosynthetic pathway, and 4 members belonged to subgroup 7, with them regulating the expression of early biosynthetic genes in the anthocyanin biosynthetic pathway. Quantitative real-time PCR (qRT-PCR) analysis was used to validate the data of RNA sequencing (RNA-Seq). The relative expression profiles of most candidate genes were consistent with the FPKM of RNA-seq. This study identified the key structural genes encoding enzymes and TFs that affect anthocyanin biosynthesis, which provides a basis and reference for the regulation of plant anthocyanin biosynthesis in I. germanica.

A comparative metabolomics investigation of flavonoid variation in faba bean flowers

INTRODUCTION

Faba bean (Vicia faba L.) flowers are edible and used as garnishes because of their aroma, sweet flavor and attractive colors. Anthocyanins are the common plant pigments that give flowers their vivid colors, whereas non-anthocyanin flavonoids can serve as co-pigments that can modify the color intensity of flowers.

OBJECTIVES

To explore the polyphenol diversity and differences in standard and wing petals of faba bean flowers; and identify glycosylated flavonoids that contribute to flower color.

METHODS

Flower standard and wing petals from 30 faba bean genotypes (eight color groups with a total of 60 samples) were used for polyphenol extraction. Samples were analyzed using a targeted method and a semi-untargeted analysis using liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined with photodiode array (PDA) detection. Compound Discoverer software was used for polyphenol identification and multivariate analysis.

RESULTS

The semi-untargeted analysis guided by the PDA detected 90 flavonoid metabolites present in faba bean flower petals. Ten anthocyanins largely influenced the flower colors, but other flavonoids (63 flavonols and 12 flavones) found with variable levels in different flower color groups appeared to also influence color, especially in mixed colors.

CONCLUSION

Analysis of the different colored faba bean flowers confirmed that the color variation between the flowers was mainly controlled by anthocyanins in brown, red and purple-red flowers. Of the other flavonoids, multiglycosylated kaempferols were abundant in white and brown flowers, monoglycosylated kaempferols were common in red and purple-red flowers, and quercetin and apigenin glycosides were abundant co-pigments in purple-red flowers.

Dracocephalum jacutense Peschkova from Yakutia: Extraction and Mass Spectrometric Characterization of 128 Chemical Compounds

Dracocephalum jacutense Peschkova is a rare and endangered species of the genus Dracocephalum of the Lamiaceae family. The species was first described in 1997 and listed in the Red Data Book of Yakutia. Significant differences in the multicomponent composition of extracts from D. jacutense collected in the natural environment and successfully introduced in the Botanical Garden of Yakutsk were identified by a team of authors earlier in a large study. In this work, we studied the chemical composition of the leaves, stem, and inflorescences of D. jacutense using the tandem mass spectrometry method. Only three cenopopulations of D. jacutense were found by us in the territory of the early habitat-in the vicinity of the village of Sangar, Kobyaysky district of Yakutia. The aboveground phytomass of the plant was collected, processed and dried as separate parts of the plant: inflorescences, stem and leaves. Firstly, a total of 128 compounds, 70% of which are polyphenols, were tentatively identified in extracts of D. jacutense. These polyphenol compounds were classified as 32 flavones, 12 flavonols, 6 flavan-3-ols, 7 flavanones, 17 phenolic acids, 2 lignans, 1 dihydrochalcone, 4 coumarins, and 8 anthocyanidins. Other chemical groups were presented as carotenoids, omega-3-fatty acids, omega-5-fatty acids, amino acids, purines, alkaloids, and sterols. The inflorescences are the richest in polyphenols (73 polyphenolic compounds were identified), while 33 and 22 polyphenols were found in the leaves and stems, respectively. A high level of identity for polyphenolic compounds in different parts of the plant is noted for flavanones (80%), followed by flavonols (25%), phenolic acids (15%), and flavones (13%). Furthermore, 78 compounds were identified for the first time in representatives of the genus Dracocephalum, including 50 polyphenolic compounds and 28 compounds of other chemical groups. The obtained results testify to the unique composition of polyphenolic compounds in different parts of D. jacutense.

Transcriptome Analysis of Key Genes Involved in Color Variation between Blue and White Flowers of Iris bulleyana

Iris bulleyana Dykes (Southwest iris) is an extensively distributed Iridaceae species with blue or white flowers. Hereby, we performed a systematic study, employing metabolomics and transcriptomics to uncover the subtle color differentiation from blue to white in Southwest iris. Fresh flower buds from both cultivars were subjected to flavonoid/anthocyanin and carotenoid-targeted metabolomics along with transcriptomic sequencing. Among 297 flavonoids, 24 anthocyanins were identified, and 13 showed a strong down-accumulation pattern in the white flowers compared to the blue flowers. Significant downregulation of 3GT and 5GT genes involved in the glycosylation of anthocyanins was predicted to hinder the accumulation of anthocyanins, resulting in white coloration. Besides, no significant altered accumulation of carotenoids and expression of their biosynthetic genes was observed between the two cultivars. Our study systematically addressed the color differentiation in I. bulleyana flowers, which can aid future breeding programs.

Development of approach for flavonoid profiling of biotechnological raw materials Iris sibirica L. by HPLC with high-resolution tandem mass spectrometry

INTRODUCTION

Iris L. are promising in medicine due to the biological activity of extracts. Iris sibirica L. is spread in Russia but its phytochemical composition has not been studied in detail though it is included in the Red Book. For this reason, I. sibirica L. biotechnology is in high demand. One of the key points in biotechnology is the regulation of plant metabolism using phytohormones. Obtaining of chromatographic metabolite profiles allows to control this process.

OBJECTIVE

The aim of this study was to develop an approach for effective control of biotechnological raw materials of I. sibirica L. by flavonoid profiles using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and to investigate the influence of phytohormones in nutrient media on content of flavonoids.

METHODOLOGY

Iris sibirica L. regenerated plants were grown on Murashige-Skoog media with 6-benzylaminopurine (6-BAP) and α-naphtylacetic acid (NAA) additives. To optimise extraction conditions, the design of the experiment was used. Profiles of polyphenols were obtained by HPLC-MS/MS in the positive and negative ionisation modes.

RESULTS

The process for efficient extraction from leaves of I. sibirica L. were developed. The factors influencing the extraction efficiency of flavonoids have been determined. A total of 36 compounds were identified by HPLC-MS/MS. Among them isoflavones and their glycosides are the main classes. Addition of an auxin-like hormone increased the non-polar flavonoid levels, but decreased the polar ones. The variation in concentration of cytokinin (6-BAP) affected almost all of the analytes.

CONCLUSION

The methodology for effective control of I. sibirica L. raw plant material biotechnology was developed by analysing obtained chromatographic polyphenol profiles.

Application of Large-Scale Molecular Prediction for Creating the Preferred Precursor Ions List to Enhance the Identification of Ginsenosides from the Flower Buds of Panax ginseng

This work was designed to evaluate the coverage of data-dependent acquisition (DDA) extensively utilized in the untargeted metabolite/component identification in the food sciences and pharmaceutical analysis. Using saponins from the flower buds of Panax ginseng (PGF) as an example, precursor ions list (PIL)-including DDA on a Q-Orbitrap mass spectrometer could enable higher coverage than the other four MS² acquisition approaches in characterizing PGF ginsenosides. A "Virtual Library of Ginsenoside" containing 13,536 ginsenoside molecules was established by C-language-programmed large-scale molecular prediction, which in combination with mass defect filtering could create a new PIL involving 1859 PGF saponin precursors. We could newly obtain the MS² spectra of at least 17 components and characterize 36 ginsenosides with unknown masses, among the 164 compounds identified from PGF. Conclusively, a molecular-prediction-oriented PIL in DDA can assist to discover more potentially novel molecules benefiting to the development of functional foods and new drugs.

Exploring the Use of Iris Species: Antioxidant Properties, Phytochemistry, Medicinal and Industrial Applications

The genus Iris from the Iridaceae family consists of more than 262 recognized species. It is an ornamental and medicinal plant widely distributed in the Northern Hemisphere. Iris species convey a long history as valuable traditional drugs with a wide variety of applications in various cultures, having been recorded since medieval times. Currently, Iris spp. still find application in numerous fields, including cosmetics, pharmaceutics and the food industry. Moreover, many of their empirical uses have been validated by in vitro and in vivo studies, showing that Iris spp. exhibit potent antioxidant, anticancer, anti-inflammatory, hepatoprotective, neuroprotective and anti-microbial properties. Phytochemicals investigations have revealed that the plant extracts are rich in phenolic compounds, especially flavonoids and phenolic acids. As such, they constitute a promising lead for seeking new drugs with high susceptibilities towards various health issues, particularly oxidative-stress-related diseases such as cancers, neurodegenerative diseases, cardiovascular diseases, diabetes, etc. Herein, we present a literature review of the genus Iris intending to determine the plant’s chemical profile and establish a coherent overview of the biological applications of the plant extracts with reference to their traditional uses.

Biological effects of gamma-ray radiation on tulip (Tulipa gesneriana L.)

Tulip, being an important ornamental plant, generally requires lengthy and laborious procedures to develop new varieties using traditional breeding methods requires. But ionizing radiation potentially accelerates the breeding process of ornamental plant species. The biological effects of γ-ray irradiation on tulip, therefore, were investigated through establishing an irradiation-mediated mutation breeding protocol to accelerate its breeding process. ISSR-PCR molecular marker technique was further used to identify the mutants of phenotypic variation plants. This study showed that low irradiation doses (5 Gy) stimulated bulb germination to improve the survival rate of tulip, while high irradiation doses (20 to 100 Gy) significantly (P < 0.05) inhibited its seed germination and growth, and decreased the flowering rate, petal number, flower stem length and flower diameter. More than 40 Gy significantly (P < 0.05) decreased the total chlorophyll content and increased the malondialdehyde (MDA) content in tulips. Interestingly, three types of both stigma variations and flower pattern variations, and four types of flower colour variations were observed. With increasing the irradiation dose from 5 to 100 Gy, the anthocyanin and flavonoid contents continuously decreased. Scanning electron microscopy (SEM) analysis evidenced that high irradiation doses altered the micromorphology of leaf stomata. Microscopic observations of tulip root apical mitosis further showed the abnormal chromosomal division behaviour occurring at different mitotic phases under irradiation treatment (80 Gy). Increasing the irradiation dose from 20 to 100 Gy enhanced the micronucleus rate. Moreover, the suspected genetic variation in tulips was evaluated by inter-simple sequence repeat (ISSR) analysis, and the percentage of polymorphic bands was 68%. Finally, this study concludes that that 80 Gy may be an appropriate radiation does to better enhance the efficiency of mutagenic breeds in tulip plants. Using γ-ray irradiation, therefore, is expected to offer a theoretical basis for mutation breeding in tulips.

Composition of Flavonoids in the Petals of Freesia and Prediction of Four Novel Transcription Factors Involving in Freesia Flavonoid Pathway

Freesia hybrida is rich in flower colors with beautiful flower shapes and pleasant aroma. Flavonoids are vital to the color formation of its flowers. In this study, five Freesia cultivars with different flower colors were used to study on the level of accumulation of their flavonoids and expression of flavonoid-related genes and further explore new novel transcription factor (TF). Ultra-high-performance liquid chromatography and VION ion mobility quadrupole time-of-flight mass spectrometer (UPLC-Q-TOF-MS) were used to determine the flavonoids. Combined with transcriptome sequencing technology, the molecular mechanism of the flavonoid metabolism difference in Freesia was revealed. A total of 10 anthoxanthin components and 12 anthocyanin components were detected using UPLC-Q-TOF-MS. All six common anthocyanin aglycones in high plants, including cyanidin, delphinidin, petunidin, peonidin, malvidin, and pelargonidin, were detected in Freesia at first time in this study. In orange, yellow, and white cultivars, anthoxanthins gradually decreased with the opening of the petals, while in red and purple cultivars, anthoxanthins first increased and then decreased. No anthocyanin was detected in yellow and white cultivars, while anthocyanins increased with the opening of the petals and reached their maximum at the flowering stage (S3) in other three cultivars. The correlation analysis revealed that the color of Freesia petals was closely related to the composition and content of anthoxanthins and anthocyanins. Petals of five cultivars at S3 were then selected for transcriptome sequencing by using the Illumina Hiseq 4000 platform, and a total of 100,539 unigenes were obtained. There were totally 5,162 differentially expressed genes (DEGs) when the four colored cultivars were compared with the white cultivar at S3. Comparing all DEGs with gene ontology (GO), KEGG, and Pfam databases, it was found that the genes involved in the flavonoid biosynthesis pathway were significantly different. In addition, AP2, WRKY, and bHLH TF families ranked the top three among all differently expressed TFs in all DEGs. Quantitative real-time PCR (qRT-PCR) technology was used to analyze the expression patterns of the structural genes of flavonoid biosynthesis pathway in Freesia. The results showed that metabolic process was affected significantly by structural genes in this pathway, such as CHS1, CHI2, DFR1, ANS1, 3GT1, and FLS1. Cluster analysis was performed by using all annotated WRKY and AP2 TFs and the above structural genes based on their relatively expression. Four novel candidate TFs of WRKY and AP2 family were screened. Their spatiotemporal expression patterns revealed that these four novel TFs may participate in the regulation of the flavonoid biosynthesis, thus controlling its color formation in Freesia petals.

Chemical Profile, In Vitro Antioxidant, Pancreatic Lipase, and Alpha-Amylase Inhibition Assays of the Aqueous Extract of Elettaria cardamomum L. Fruits

Phytochemical and pharmacological investigations of Elettaria cardamomum L. were mostly focused on its essential oil and organic crude extracts with little attention on its aqueous extracts. Therefore, the current study aimed to investigate the phytochemical profile, in vitro antiobesity, and antidiabetic activities of the aqueous extract of Elettaria cardamomum L. family Zingiberaceae. UPLC-ESI-MS/MS analysis is used for the aqueous extract characterization in both ionization modes. The analysis revealed the tentative identification of forty-seven compounds based on their MS/MS fragmentation pattern and comparison with the reported data. The identified compounds include eight flavones, thirteen phenolic and nonphenolic acids, one coumarin, and nineteen anthocyanins. Moreover, the in vitro antiobesity and antidiabetic activities were also studied. The results showed that E. cardamomum L. aqueous extract inhibits pancreatic lipase and α-amylase enzyme in a concentration-dependent manner, as 1 mg/mL extract was able to inhibit pancreatic lipase and α-amylase by 62.25% ± 0.58 (IC50 = 288.75 ± 1.3 µg/mL) and 70.42% ± 1.5 (IC50 = 220.5 ± 1.3 µg/mL), respectively. Conclusively, the current study indicated that the investigated biological activities of Elettaria cardamomum aqueous extract were attributed to the existence of biologically active metabolites such as flavones, phenolic and nonphenolic acids, coumarins, and anthocyanins. Moreover, it proposed that the aqueous cardamom extract can be used as a natural potential source in different pharmaceutical preparations to protect against variable chronic disorders, especially obesity and diabetes. Deeper in vivo investigations, isolation, purification, and structural elucidation of the major active metabolites from cardamom are recommended.

Recent applications of ion mobility spectrometry in natural product research

Ion mobility spectrometry (IMS) is a rapid separation technique capable of extracting complementary structural information to chromatography and mass spectrometry (MS). IMS, especially in combination with MS, has experienced inordinate growth in recent years as an analytical technique, and elicited intense interest in many research fields. In natural product analysis, IMS shows promise as an additional tool to enhance the performance of analytical methods used to identify promising drug candidates. Potential benefits of the incorporation of IMS into analytical workflows currently used in natural product analysis include the discrimination of structurally similar secondary metabolites, improving the quality of mass spectral data, and the use of mobility-derived collision cross-section (CCS) values as an additional identification criterion in targeted and untargeted analyses. This review aims to provide an overview of the application of IMS to natural product analysis over the last six years. Instrumental aspects and the fundamental background of IMS will be briefly covered, and recent applications of the technique for natural product analysis will be discussed to demonstrate the utility of the technique in this field.

Understanding Alstroemeria pallida Flower Colour: Links between Phenotype, Anthocyanins and Gene Expression

Flower colour is mainly due to the accumulation of flavonoids, carotenoids and betalains in the petals. Of these pigments, flavonoids are responsible for a wide variety of colours ranging from pale yellow (flavones, flavonols and flavanodiols) to blue-violet (anthocyanins). This character plays a crucial ecological role by attracting and guiding pollinators. Moreover, in the ornamental plants market, colour has been consistently identified as the main feature chosen by consumers when buying flowers. Considering the importance of this character, the aim of this study was to evaluate flower colour in the native Chilean geophyte Alstroemeria pallida, by using three different approaches. Firstly, the phenotype was assessed using both a colour chart and a colourimeter, obtaining CIELab parameters. Secondly, the anthocyanin content of the pigmented tepals was evaluated by high-performance liquid chromatography (HPLC), and finally, the expression of two key flavonoid genes, chalcone synthase (CHS) and anthocyanidin synthase (ANS) was analysed using real-time polymerase chain reaction (PCR). Visual evaluation of A. pallida flower colour identified 5 accessions, ranging from white (Royal Horticultural Society (RHS) N999D) to pink (RHS 68C). Moreover, this visual evaluation of the accessions correlated highly with the CIELab parameters obtained by colourimetry. An anthocyanidin corresponding to a putative 6-hydroxycyanidin was identified, which was least abundant in the white accession (RHS N999D). Although CHS was not expressed differentially between the accessions, the expression of ANS was significantly higher in the accession with pink flowers (RHS 68C). These results suggest a correlation between phenotype, anthocyanin content and ANS expression for determining flower colour of A. pallida, which could be of interest for further studies, especially those related to the breeding of this species with ornamental value.

Identification of anthocyanin compositions in black seed coated Korean adzuki bean (Vigna angularis) by NMR and UPLC-Q-Orbitrap-MS/MS and screening for their antioxidant properties using different solvent systems

The aim of the present research was to investigate the antioxidant properties and anthocyanin profiles in the black seed coated adzuki bean (Vigna angularis, Geomguseul cultivar). The acidic 60% methanol extract (40 μg/mL) contains the highest total phenolic and flavonoid contents (486 ± 3 mg GAE/100 g; 314 ± 10 mg CE/100 g) with potent antioxidant properties (trolox equivalent 1272 ± 26 and 662 ± 24 mg TE/100 g) against ABTS and DPPH radicals compared to other methanol-water ratios (20, 40, 80, and 100%). Ten anthocyanin components were identified in this extract including delphinidin-3,5-O-digalactoside (1), delphinidin-3,5-O-diglucoside (2), delphinidin-3-O-galactoside (3), delphinidin-3-O-glucoside (4), delphinidin-3-O-rutinoside (5), delphinidin-3-O-(p-coumaroyl)glucoside (6), cyanidin-3-O-glucoside (7), petunidin-3-O-galactoside (8), petunidin-3-O-glucoside (9) and petunidin-3-O-(p-coumaroyl)glucoside (10) via NMR spectroscopy and UPLC-Q-Orbitrap-MS/MS analysis. The key anthocyanins 3 and 4 of delphinidin type were isolated by reversed phase C-18 MPLC. Our results indicate that the anthocyanin profiles as well as the high phenolic and flavonoid contents are important factors determining the antioxidant effects of black adzuki bean.

Flavonoids and Xanthones From the Genus Iris: Phytochemistry, Relationships with Flower Colors and Taxonomy, and Activities and Function

The genus Iris consists of approximately 360 species and is distributed to Eurasia, North Africa, and North America. Belamcanda chinensis was incorporated into the genus Iris by APG III as Iris domestica. Iris species have also been cultivated as ornamentals since ancient times. Many flavonoids are isolated and identified from the flowers, leaves, and rhizomes. So far as we know, 6 anthocyanidins, 13 flavones, 20 flavonols, 20 C-glycosylflavones, 14 flavanones, 11 dihydroflavonols, 6 flavan and proanthocyanidins, and 85 isoflavonoids were reported as aglycones and glycosides. However, chalcones, dihydrochalcones, aurones, biflavonoids, and neoflavonoids are not found in the genus Iris. Fifteen xanthones that are related to flavonoids were also isolated from Iris species. In this review, we describe the flavonoids and xanthones that were isolated and characterized from Iris species. Moreover, their phytochemistry, contribution to the flower colors, relationships with taxonomy, and activities and functions are also discussed.

Metabolic and transcriptomic analysis related to flavonoid biosynthesis during the color formation of Michelia crassipes tepal

Michelia crassipes is the only plant with purple flowers amongst Michelia species, and its tepals exhibit an obvious color change from green to purple. In this study, a combination of metabolic and transcriptomic analyses was conducted at three stages of tepals in Michelia crassipes: green tepal, purple spot-containing tepal, and totally purple tepal. Several classes of flavonoid compounds were detected and cyanidin 3-rutinoside and delphinidin 3-glucoside were the major anthocyanins underlying the purple color formation, along with co-pigmentation of flavone compounds represented by luteolin derivatives and flavonol compounds represented by kaempferol and quercetin derivatives. Transcriptome analysis revealed up-regulation of genes encoding enzymes involved in the conversion of phenylpropanoid for flavonoid biosynthesis in Stage 1 vs. Stage 2, whereas up-regulation of most flavonoid biosynthesis genes was observed in Stage 1 vs. Stage 3. MYB, bHLH, and WD40 isoforms, as well as other classes of transcriptional factors, also exhibited differential expression. In addition, differentially expressed genes putatively related to the transport of flavonoids were also identified. The results of the current study provide insight into the regulatory mechanism underlying the color transition from green to purple in Michelia crassipes tepals and describe a complicated network involving PAL, transporter genes, and transcription factors, specifically responsible for the emergence of purple color in Stage 1 vs. Stage 2.

Anthocyanins, Vibrant Color Pigments, and Their Role in Skin Cancer Prevention

Until today, numerous studies evaluated the topic of anthocyanins and various types of cancer, regarding the anthocyanins' preventative and inhibitory effects, underlying molecular mechanisms, and such. However, there is no targeted review available regarding the anticarcinogenic effects of dietary anthocyanins on skin cancers. If diagnosed at the early stages, the survival rate of skin cancer is quite high. Nevertheless, the metastatic form has a short prognosis. In fact, the incidence of melanoma skin cancer, the type with high mortality, has increased exponentially over the last 30 years, causing the majority of skin cancer deaths. Malignant melanoma is considered a highly destructive type of skin cancer due to its particular capacity to grow and spread faster than any other type of cancers. Plants, in general, have been used in disease treatment for a long time, and medicinal plants are commonly a part of anticancer drugs on the market. Accordingly, this work primarily aims to emphasize the most recent improvements on the anticarcinogenic effects of anthocyanins from different plant sources, with an in-depth emphasis on melanoma skin cancer. We also briefly summarized the anthocyanin chemistry, their rich dietary sources in flowers, fruits, and vegetables, as well as their associated potential health benefits. Additionally, the importance of anthocyanins in topical applications such as their use in cosmetics is also given.

Rapid analysis of anthocyanin and its structural modifications in fresh tomato fruit

Anthocyanin is derived from a flavylium cation structure, and it promotes health in humans and functions in plants as protection against environmental stress. The rapid analysis of anthocyanin structure and content is a critical challenge for improving fruit quality. In this study, the tomato cultivar Indigo Rose, which is a popular purple cultivated tomato used for breeding, was taken as an example for anthocyanin analysis. A rapid analysis method was developed to minimize anthocyanin loss from the fresh fruit. Four new anthocyanins were discovered in the tomato, and the structures of a total of 12 anthocyanins were determined. Among these, petunidin-3-(trans-p-coumaroyl)-rutinoside-5-glucoside and malvidin-3-(trans-p-coumaroyl)-rutinoside-5-glucoside were the main anthocyanins in Indigo Rose. The structural modifications of these anthocyanins were mainly glycosylation and acylation, and there were also hydroxylation and methylation. Our findings provide new insight into the biosynthesis pathway in tomato fruit.

Accumulation of Anthocyanins through Overexpression of AtPAP1 in Solanum nigrum Lin. (Black Nightshade)

Black nightshade (Solanum nigrum) belongs to the Solanaceae family and is used as a medicinal herb with health benefits. It has been reported that the black nightshade plant contains various phytochemicals that are associated with antitumor activities. Here we employed a genetic approach to study the effects of overexpression of Arabidopsis thaliana production of anthocyanin pigment 1 (AtPAP1) in black nightshade. Ectopic expression of AtPAP1 resulted in enhanced accumulation of anthocyanin pigments in vegetative and reproductive tissues of the transgenic plants. Analysis of anthocyanin revealed that delphinidin 3-O-rutinoside-5-O-glucoside, delphinidin 3,5-O-diglucoside, delphinidin 3-O-rutinoside, petunidin 3-O-rutinoside (cis-p-coumaroyl)-5-O-glucoside, petunidin 3-(feruloyl)-rutinoside-5-glucoside, and malvidin 3-(feruloyl)-rutinoside-5-glucoside are highly induced in the leaves of AtPAP1 overexpression lines. Furthermore, ectopic expression of AtPAP1 evoked expression of early and late biosynthetic genes of the general phenylpropanoid and flavonoid pathways that include phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate CoA ligase (4CL), chalcone isomerase (CHI), and quinate hydroxycinnamoyl transferase (HCT), which suggests these genes might be transcriptional targets of AtPAP1 in black nightshade. Concomitantly, the total content of anthocyanin in the transgenic black nightshade plants was higher compared to the control plants, which supports phenotypic changes in color. Our data demonstrate that a major anthocyanin biosynthetic regulator, AtPAP1, can induce accumulation of anthocyanins in the heterologous system of black nightshade through the conserved flavonoid biosynthesis pathway in plants.

Detailed Phenolic Characterization of Protea Pure and Hybrid Cultivars by Liquid Chromatography-Ion Mobility-High Resolution Mass Spectrometry (LC-IM-HR-MS)

In this study we report a detailed investigation of the polyphenol composition of Protea pure (P. cynaroides and P. neriifolia) and hybrid cultivars (Black beauty and Limelight). Aqueous methanol extracts of leaf and bract tissues were analyzed by ultrahigh pressure liquid chromatography hyphenated to photodiode array and ion mobility-high resolution mass spectrometric (UHPLC-PDA-IM-HR-MS) detection. A total of 67 metabolites were characterized based on their relative reversed phase (RP) retention, UV-vis spectra, low and high collision energy HR-MS data, and collisional cross section (CCS) values. These metabolites included 41 phenolic acid esters and 25 flavonoid derivatives, including 5 anthocyanins. In addition, an undescribed hydroxycinnamic acid-polygalatol ester, caffeoyl-O-polygalatol (1,5-anhydro-[6-O-caffeoyl]-sorbitol(glucitol)) was isolated and characterized by 1D and 2D NMR for the first time. This compound and its isomer are shown to be potential chemo-taxonomic markers.