Celochalcoside, a new quinochalcone C-glycoside from Celosia trigyna.

A new quinochalcone C-glycoside featuring a unique quinonoid moiety, named celochalcoside (1), was isolated from the n-butanol extract of the aerial parts of Celosia trigyna L. The structure was determined by extensive spectroscopic analysis as well as mass spectrometric data. Compound 1 showed moderate cytotoxic activities against breast cancer cell lines (MCF-7), colon cancer cell lines (HT-29) and hepatocellular carcinoma cell lines (HepG2) with IC50 values of 23.16, 37.05 and 18.35 µg/ml, respectively.

Identification of the Genes Coding for Carthamin Synthase, Peroxidase Homologs that Catalyze the Final Enzymatic Step of Red Pigmentation in Safflower (Carthamus tinctorius L.).

Carthamin, a dimeric quinochalcone that is sparingly soluble in water, is obtained from the yellow-orange corolla of fully blooming safflower (Carthamus tinctorius L.) florets. Carthamin is a natural red colorant, which has been used worldwide for more than 4500 years and is the major component of Japanese 'beni' used for dyeing textiles, in cosmetics and as a food colorant. The biosynthetic pathway of carthamin has long remained uncertain. Previously, carthamin was proposed to be derived from precarthamin (PC), a water-soluble quinochalcone, via a single enzymatic process. In this study, we identified the genes coding for the enzyme responsible for the formation of carthamin from PC, termed 'carthamin synthase' (CarS), using enzyme purification and transcriptome analysis. The CarS proteins were purified from the cream-colored corolla of safflower and identified as peroxidase homologs (CtPOD1, CtPOD2 and CtPOD3). The purified enzyme catalyzed the oxidative decarboxylation of PC to produce carthamin using O2, instead of H2O2, as an electron acceptor. In addition, CarS catalyzed the decomposition of carthamin. However, this enzymatic decomposition of carthamin could be circumvented by adsorption of the pigment to cellulose. These CtPOD isozymes were not only expressed in the corolla of the carthamin-producing orange safflower cultivars but were also abundantly expressed in tissues and organs that did not produce carthamin and PC. One CtPOD isozyme, CtPOD2, was localized in the extracellular space. Based on the results obtained, a model for the stable red pigmentation of safflower florets during flower senescence and the traditional 'beni' manufacturing process is proposed.

Two new quinochalcone glycosides from the safflower yellow pigments.

Two new quinochalcone glycosides, hydroxysafflor yellow A-4'-O-ß-D-glucopyranoside (1) and 3'-hydroxyhydroxysafflor yellow A (2), were isolated from the safflower yellow pigments of Carthamus tinctorius. The structures of new compounds were elucidated by a detailed spectroscopic analysis (UV, IR, HR-ESI-MS, 1D and 2D NMR, ECD). The in vitro assay indicated that compound 1 could improve the survived rate of primary mouse cortical neurons on glutamate-induced neurons damage model at a concentration of 10 µM.

Mass Spectrometry for Investigation of Natural Dyes in Historical Textiles: Unveiling the Mystery behind Safflower-Dyed Fibers.

Safflower (Carthamus tinctorius L.) petals, depending on the nature of a dyeing bath, dye fibers yellow or red. This is due to the presence of two kinds of components, water-soluble yellow colorants and alkali-soluble red compounds. In this study, safflower-yellow- and safflower-red-dyed silk, cotton, and wool fibers were investigated using high- or ultrahigh-performance liquid chromatography hyphenated with spectrophotometry and tandem mass spectrometry (HPLC-UV-vis-ESI-MS/MS) and high-resolution Orbitrap mass spectrometry (HPLC-HESI-HRMS) in order to identify the natural dye in historical textiles. This way, several quinochalcone C-glycosides were separated and characterized. Their low- and high-resolution MS/MS spectra expanded the database of natural colorants in cultural heritage objects. Moreover, the colorless ct-markers (with a hitherto unknown structure) present in all safflower-dyed fabrics, regardless of the color or preservation conditions, were revealed to be E/Z stereoisomers of N1,N5,N10-tri-p-coumaroylspermidine. Since most of the standards was not available, discussion on possible molecular structures was provided. As a consequence, the analytical investigation of the reference fibers dyed with safflower demonstrated that the dye composition varies, depending on the dyeing conditions and type of fiber. Moreover, it was proven that carthamin, although alkali soluble, can be successfully released with a mild extraction method, without its hydrolysis under these conditions. The results helped us to characterize threads sampled from 16th to 18thcentury textiles of European and Near Eastern origin. It has completed the picture of natural dyes used in the most valuable textiles availed in liturgical vestments from the collections of Krakow churches.

Therapeutic Potential of Hydroxysafflor Yellow A on Cardio-Cerebrovascular Diseases.

The incidence rate of cardio-cerebrovascular diseases (CCVDs) is increasing worldwide, causing an increasingly serious public health burden. The pursuit of new promising treatment options is thus becoming a pressing issue. Hydroxysafflor yellow A (HSYA) is one of the main active quinochalcone C-glycosides in the florets of Carthamus tinctorius L., a medical and edible dual-purpose plant. HSYA has attracted much interest for its pharmacological actions in treating and/or managing CCVDs, such as myocardial and cerebral ischemia, hypertension, atherosclerosis, vascular dementia, and traumatic brain injury, in massive preclinical studies. In this review, we briefly summarized the mode and mechanism of action of HSYA on CCVDs based on these preclinical studies. The therapeutic effects of HSYA against CCVDs were presumed to reside mostly in its antioxidant, anti-inflammatory, and neuroprotective roles by acting on complex signaling pathways.

Base-catalyzed oxidative dearomatization of multisubstituted phloroglucinols: An easy access to C-glucosyl 3,5,6-trihydroxycyclohexa-2,4-dienone derivatives.

An efficient and simple method for the protecting group-free synthesis of C-glucosyl 3,5,6-trihydroxycyclohexa-2,4-dienone has been firstly established. This method is compatible with various functional groups, such as benzyl and phenethyl groups, affording a range of C-glucosyl 3,5,6-trihydroxycyclohexa-2,4-dienone derivatives.

Overexpression of CtCHS1 Increases Accumulation of Quinochalcone in Safflower.

Carthami flos, the dried petal of safflower (Carthamus tinctorius L.) has been widely used in traditional Chinese medicine to treat cardiovascular and cerebrovascular diseases, in which quinochalcone glucosides such as hydrosafflower yellow A (HSYA), carthamin are uniquely present and have been identified as active compounds. In the present study, through sequencing of a safflower floret cDNA library and subsequent microarray analysis, we found 23 unigenes (5 PALs, 1 C4Hs, 5 4CLs, 6 CHSs, 2 CHIs, 2 DFRs, 2 FLSs) involved in flavonoid pathway, of which 4 were up-regulated differentially during quinochalcone glucosides accumulation with the floret developing stage. The up-regulated genes were verified by PCR methods. Considering chalcone synthase are entry enzyme in flavonoid biosynthesis, CHS1 was focused on target gene to verify its function furtherly. Bioinformation analysis showed that CHS1 shared 86.94% conserved residues with CHS from other plants. Subcellular localization showed that CtCHS1 was localized in cytoplasm in onion epidermal cells. The transgenic safflower plant with overexpression CtCHS1 by Agrobacterium-mediated pollen-tube pathway method was firstly generated. The results present that expression of PAL2, PAL3, CHS1, CHS4, CHS6 increased and expression of CHI1 and CHI2 decreased in the transgenic plant floret. Meanwhile, the accumulation of quinochalcone glucosides increased by ∼20-30% and accumulation of quercetin-3-ß-D-glucoside and quercetin decreased by 48 and 63% in the transgenic plant floret. These results suggested that CtCHS1 played an important role in quinochalcone glucosides biosynthesis rather than flavonol biosynthesis. These results also demonstrated that the pollen-tube pathway method was an efficient method for gene transformation in safflower. Our study will provide a deep understanding of potential synthetic genes involved in quinochalcone biosynthetic pathway.

Selective ion monitoring of quinochalcone C-glycoside markers for the simultaneous identification of Carthamus tinctorius L. in eleven Chinese patent medicines by UHPLC/QTOF MS.

Current China Pharmacopoeia standards for the Chinese patent medicines (CPMs) that contain one or several the same drug(s) employ case-dependent TLC or HPLC approaches to achieve qualitative identification. A qualitative "monomethod-heterotrait matrix" (MHM) strategy is thus proposed, by selective monitoring of multi-biomarkers, to achieve the identification of different CPMs. Carthamus tinctorius L. (safflower) is a reputable gynecological herbal medicine containing characteristic quinochalcone C-glycosides (QCGs) as the major bioactive components. Qualitative identification of safflower in diverse CPMs by selective monitoring of QCG markers was performed by use of the MHM strategy. Initially, 27 QCG analogs (involving 16 potentially new ones) were selectively characterized by product ion filtering (m/z 119.05) and integrated analysis of the negative mode MS(E) and Fast DDA data obtained on a UHPLC/QTOF mass spectrometer. Subsequently, by fingerprint analysis of 20 batches of safflower samples followed by a thermostable test, six QCGs (hydroxysafflor yellow A and its two isomers, anhydrosafflor yellow B, safflomin C, and isosafflomin C) were selected as the biomarkers for safflower. Then, a highly specific selective ion monitoring (SIM) method by recording centroided data was developed and applied to selectively profile six QCG biomarkers from 28 batches of CPM samples collected from versatile vendors. By reference to a standard SIM spectrum established using a home-made safflower reference extract, simultaneous identification of safflower in eleven different CPMs was accomplished with the unified sample preparation and a single UHPLC/QTOF-SIM method. The qualitative MHM strategy represents the novel methodology that facilitates the quality control of CPMs more efficiently.

Diversified bioactivities of four types of naturally occurring quinochalcones.

Quinochalcones, quinone-containing chalcones, belong to the flavonoid family and have attracted increasing popularity in Western countries in the last decade due to their pharmacological activities. This review describes four types of naturally occurring quinochalcones and summarizes their different pharmacological activities, including anti-cerebral ischemia, anti-tumor, and anti-infection activities. In addition, the pharmacological activities and relevant structure-activity relationships of synthetic quinochalcones are also reviewed.