Towards environmentally-friendly solutions for real textile-dyeing wastewater with energy recovery: Effluent recirculation and Rubia plant-derived purpurin electron mediator in microbial fuel cell.

Escalating global water pollution exacerbated by textile-dyeing wastewater (TDW) poses significant environmental and health concerns due to the insufficient treatment methods being utilized. Thus, it is imperative to implement more effective treatment solutions to address such issues. In this research, different environmentally-friendly strategies involving effluent recirculation (ER) and Rubia cordifolia plant-derived purpurin electron mediator (EM) were introduced to enhance the treatment of real TDW and bioelectricity generation performance of an anti-gravity flow microbial fuel cell (AGF-MFC). The results revealed that optimum performance was achieved with a combination of hydraulic retention time (HRT) of 48 h with a recirculation ratio of 1, where the reduction efficiency of biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium (NH4+), nitrate (NO3-), sulphate (SO42-), ammonia nitrogen (NH3-N), colour and turbidity were 82.17 %, 82.15 %, 85.10 %, 80.52 %, 75.91 %, 59.52 %, 71.02 % and 93.10 %, respectively. In terms of bioelectricity generation performance, AGF-MFC showed a maximum output voltage and power density of 404.72 mV and 65.16 mW/m2, respectively. Moreover, the results also signified that higher treatment performance of TDW was obtained with natural purpurin from Rubia cordifolia plant than synthetic purpurin as EM. The reduced reactivity of highly stable synthetic purpurin EM for mediating the electron transfer was a contributing factor to the outperformance of plant-derived purpurin. Additionally, detailed electron-mediating mechanisms of purpurin were proposed to unravel the underlying electron transfer pathway involved in AGF-MFC. This research offers insight into the development of more sustainable solutions for managing TDW, and consequently reducing environmental pollution.

Characterization and antimicrobial evaluation of anthraquinones and triterpenes from Rubia cordifolia.

Chemical investigation of roots of the plant, Rubia cordifolia Linn, led to the isolation of an undescribed anthraquinone, cordifoquinone R, determined as 1,2-dihydroxy-6-methoxyanthracene-9,10-dione (6) based on the 1D and 2D NMR analyses and HRESIMS. Ten other known compounds viz.1,4-dihydroxy-2-methoxyanthracene-9,10-dione (1), rubiadin (2), xanthopurpurin (3), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), alizarin (5), ß-sitosterol glucoside (7), scopoletin (8), oleanolic acid, (9), pomolic acid (10), queretaroic acid (11) were also isolated. Out of these compounds, 4, 10, and 11 are first reported from this plant species. Compounds 2, 3, 6, 7, and 10 showed activity in the range of 16-32 µg/ml against S. aureus ATCC 29213.

Noninvasive Characterization and Quantification of Anthraquinones in Dyed Woolen Threads by Visible Diffuse Reflectance Spectroscopy.

The anthraquinone components of the roots of various species of madder (like Rubia tinctorum L. and Rubia peregrina L.) have been used for millennia as red colorants in textiles, carpets, tapestries, and other objects. To understand the selection and preparation of dyestuffs in various cultures and historical periods, these dyes (mainly alizarin and purpurin) are traditionally analyzed by means of separation methods that require sampling. This contribution focuses on establishing a fast, noninvasive, and in situ analytical procedure based on visible reflectance spectroscopy for the characterization and quantification of anthraquinones in ancient wool yarns. The method was successfully applied to Coptic textiles, and the analytical results are in agreement with prior observations obtained on samples by separation techniques.

ZnO Nanoparticles of Rubia cordifolia Extract Formulation Developed and Optimized with QbD Application, Considering Ex Vivo Skin Permeation, Antimicrobial and Antioxidant Properties.

The objective of the current research is to develop ZnO-Manjistha extract (ZnO-MJE) nanoparticles (NPs) and to investigate their transdermal delivery as well as antimicrobial and antioxidant activity. The optimized formulation was further evaluated based on different parameters. The ZnO-MJE-NPs were prepared by mixing 10 mM ZnSO4·7H2O and 0.8% w/v NaOH in distilled water. To the above, a solution of 10 mL MJE (10 mg) in 50 mL of zinc sulfate was added. Box-Behnken design (Design-Expert software 12.0.1.0) was used for the optimization of ZnO-MJE-NP formulations. The ZnO-MJE-NPs were evaluated for their physicochemical characterization, in vitro release activity, ex vivo permeation across rat skin, antimicrobial activity using sterilized agar media, and antioxidant activity by the DPPH free radical method. The optimized ZnO-MJE-NP formulation (F13) showed a particle size of 257.1 ± 0.76 nm, PDI value of 0.289 ± 0.003, and entrapment efficiency of 79 ± 0.33%. Drug release kinetic models showed that the formulation followed the Korsmeyer-Peppas model with a drug release of 34.50 ± 2.56 at pH 7.4 in 24 h. In ex vivo studies ZnO-MJE-NPs-opt permeation was 63.26%. The antibacterial activity was found to be enhanced in ZnO-MJE-NPs-opt and antioxidant activity was found to be highest (93.14 ± 4.05%) at 100 µg/mL concentrations. The ZnO-MJE-NPs-opt formulation showed prolonged release of the MJE and intensified permeation. Moreover, the formulation was found to show significantly (p < 0.05) better antimicrobial and antioxidant activity as compared to conventional suspension formulations.

Configurational Assignment of a Flexible Benzo[g]isochromene Stereodiad from Rubia philippinensis and Inhibition of Soluble Epoxide Hydrolase Activity.

A new benzo[g]isochromene possessing a conformationally mobile moiety was identified from Rubia philippinensis. The 2D structure was established utilizing spectrometric and spectroscopic techniques with variable temperatures. The configurational investigation of the flexible moiety was investigated utilizing contemporary NMR-combined computational tools such as DP4, direct J-DP4, and DP4 Plus. The probabilities computed from DP4 Plus analysis, featuring inclusion of an additional geometry optimization process, demonstrated more conclusive probability scores among the analyses used. The configurational assignment was also supported by compositional and molecular orbital analyses. Compound 1 inhibited soluble epoxide hydrolase (IC50 = 0.6 ± 0.01 µM), an enzyme associated with cardiovascular disorders.

H2O-Induced Hydrophobic Interactions in MS-Guided Counter-Current Chromatography Separation of Anti-Cancer Mollugin from Rubia cordifolia.

Counter-current chromatography (CCC) is a unique liquid-liquid partition chromatography and largely relies on the partition interactions of solutes and solvents in two-phase solvents. Usually, the two-phase solvents used in CCC include a lipophilic organic phase and a hydrophilic aqueous phase. Although a large number of partition interactions have been found and used in the CCC separations, there are few studies that address the role of water on solvents and solutes in the two-phase partition. In this study, we presented a new insight that H2O (water) might be an efficient and sensible hydrophobic agent in the n-hexane-methanol-based two-phase partition and CCC separation of lipophilic compounds, i.e., anti-cancer component mollugin from Rubia cordifolia. Although the n-hexane-methanol-based four components solvent systems of n-hexane-ethyl acetate-methanol-water (HEMWat) is one of the most popular CCC solvent systems and widely used for natural products isolation, this is an interesting trial to investigate the water roles in the two-phase solutions. In addition, as an example, the bioactive component mollugin was targeted, separated, and purified by MS-guided CCC with hexane-methanol and minor water as a hydrophobic agent. It might be useful for isolation and purification of lipophilic mollugin and other bioactive compounds complex natural products and traditional Chinese medicines.

Antioxidant and Polyphenol-Rich Ethanolic Extract of Rubia tinctorum L. Prevents Urolithiasis in an Ethylene Glycol Experimental Model in Rats.

Treatment of kidney stones is based on symptomatic medications which are associated with side effects such as gastrointestinal symptoms (e.g., nausea, vomiting) and hepatotoxicity. The search for effective plant extracts without the above side effects has demonstrated the involvement of antioxidants in the treatment of kidney stones. A local survey in Morocco has previously revealed the frequent use of Rubia tinctorum L. (RT) for the treatment of kidney stones. In this study, we first explored whether RT ethanolic (E-RT) and ethyl acetate (EA-RT) extracts of Rubia tinctorum L. could prevent the occurrence of urolithiasis in an experimental 0.75% ethylene glycol (EG) and 2% ammonium chloride (AC)-induced rat model. Secondly, we determined the potential antioxidant potency as well as the polyphenol composition of these extracts. An EG/AC regimen for 10 days induced the formation of bipyramid-shaped calcium oxalate crystals in the urine. Concomitantly, serum and urinary creatinine, urea, uric acid, phosphorus, calcium, sodium, potassium, and chloride were altered. The co-administration of both RT extracts prevented alterations in all these parameters. In the EG/AC-induced rat model, the antioxidants- and polyphenols-rich E-RT and EA-RT extracts significantly reduced the presence of calcium oxalate in the urine, and prevented serum and urinary biochemical alterations together with kidney tissue damage associated with urolithiasis. Moreover, we demonstrated that the beneficial preventive effects of E-RT co-administration were more pronounced than those obtained with EA-RT. The superiority of E-RT was associated with its more potent antioxidant effect, due to its high content in polyphenols.

Crosstalk of Cancer Signaling Pathways by Cyclic Hexapeptides and Anthraquinones from Rubia cordifolia.

The anticancer activities of Rubia cordifolia and its constituents have been reported earlier, but their influence on the crosstalk of complex cancer-related signaling metabolic pathways (i.e., transcription factors; TF) has not yet been fully investigated. In this study, R. cordifolia root extract was subjected to the cancer signaling assay based bioactivity-guided fractionation, which yielded the following compounds viz., three anthraquinones, namely alizarin (1), purpurin (2), and emodin (3); two lignans, namely eudesmin (4) and compound 5; and two cyclic hexapeptides, namely deoxybouvardin RA-V (6), and a mixture of 6+9 (RA-XXI). The structures of the isolated compounds were determined by NMR spectroscopy and HRESIMS. The isolated compounds 1, 2, 3, 6, and a mixture of 6+9 were tested against a panel of luciferase reporter genes that assesses the activity of a wide-range of cancer-related signaling pathways. In addition, reference anthraquinones viz., chrysophanol (11), danthron (12), quinizarin (13), aloe-emodin (14), and α-lapachone (15) were also tested. Among the tested compounds, the cyclic hexapeptide 6 was found to be very active against several signaling pathways, notably Wnt, Myc, and Notch with IC50 values of 50, 75, and 93 ng/mL, respectively. Whereas, the anthraquinones exhibited very mild or no inhibition against these signaling pathways. Compound 6 being the most active, we tested it for stability in simulated intestinal (SIF) and gastric fluids (SGF), since the stability in biological fluid is a key short-coming of cyclic hexapeptides. The anticancer activity of 6 was found to remain unchanged before and after the treatment of simulated gastric/intestinal fluids, indicating that RA-V was stable. As a result, it could be bioavailable when orally used in therapeutics and possibly a drug candidate for cancer treatment. The mechanism for the preferential inhibition of these pathways and the possible crosstalk effect with other previously reported signaling pathways has been discussed.

Development of an ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry method for determination of xanthopurpurin in rat plasma and its application to pharmacokinetic study.

A rapid and sensitive method was developed and validated for the quantitative determination of xanthopurpurin (XPP) in rat plasma using ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry. XPP inhibits IgE production and prevents peanut-induced anaphylaxis. The XPP and emodin (internal standard) were determined in negative ion mode with m/z 239.0350 → 211.0400 and 269.0455 → 241.0507, respectively. The separation process was achieved using an ACQUITY UPLC HSS T3 column with acetonitrile and 0.1% formic acid in water (85:15). The linear range was 0.5-100 ng/mL, and the correlation coefficient (r2 ) was > 0.993. The inter-day and intra-day precision was within an acceptable range of 15%. The extraction recovery and matrix effect were 78.9-87.2% and 94.3-98.5%, respectively. Under different conditions, the XPP was stable in the range of 5.6-10.6%. This method was successfully applied to study the pharmacokinetics of XPP with an oral dose of 10.0 mg/kg and intravenous dose of 2.0 mg/kg in rats. The absolute oral bioavailability of XPP was 4.6%.

TMARg, a Novel Anthraquinone Isolated from Rubia cordifolia Nakai, Increases Osteogenesis and Mineralization through BMP2 and ß-Catenin Signaling.

BACKGROUND: Plant extracts have long been regarded as useful medicines in the treatment of human diseases. Rubia cordifolia Nakai has been used as a traditional medicine, as it has pharmacological properties such as antioxidant and anti-inflammatory activity. However, the biological functions of TMARg, isolated from the roots of R. cordifolia, in osteoblast differentiation remain unknown. This study was performed to investigate the pharmacological effects and intracellular signaling of TMARg in the osteoblast differentiation of pre-osteoblast MC3T3-E1 cells and mesenchymal precursor C2C12 cells. METHODS: Cell viability was evaluated using an MTT assay. Early and late osteoblast differentiation was examined by analyzing the activity of alkaline phosphatase (ALP), and by staining it with Alizarin red S (ARS). Cell migration was determined by using migration assays. Western blot analysis and immunocytochemical analysis were used to examine the intracellular signaling pathways and differentiation proteins. RESULTS: In the present study, TMARg showed no cytotoxicity and increased the osteoblast differentiation in pre-osteoblasts, as assessed from the alkaline phosphate (ALP) staining and activity and ARS staining. TMARg also induced BMP2 expression and increased the p-smad1/5/8-RUNX2 and ß-catenin pathways in both MC3T3-E1 and C2C12 cells. Furthermore, TMARg activated mitogen-activated protein kinases (MAPKs) and increased the cell migration rate. In addition, the TMARg-mediated osteoblast differentiation was suppressed by BMP and Wnt inhibitors with the downregulation of BMP2 expression. CONCLUSION: These findings demonstrate that TMARg exerts pharmacological and biological effects on osteoblast differentiation through the activation of BMP2 and ß-catenin signaling pathways, and suggest that TMARg might be a potential phytomedicine for the treatment of bone diseases.

Network pharmacology-based research on the active component and mechanism of the antihepatoma effect of Rubia cordifolia L.

Rubia cordifolia L. is widely used in Asia and its antihepatoma effect has been proved by in vitro and in vivo experiments. However, there are few studies on its specific mechanism. In the present study, the network pharmacology method was used to construct the component/target/pathway molecular regulatory network for the antihepatoma effect of Rubia cordifolia L. to explore the effective components of Rubia cordifolia L. and its potential mechanism. The chemical components of Rubia cordifolia L. were identified through literature and databases, and the components were evaluated and screened by drug likeness and pharmacokinetic characteristics (ADMET). The targets of active components were predicted according to the reverse pharmacophore matching model. The hepatic carcinoma-related genes were found in databases, and antihepatoma-related gene targets were selected through comparison. The functions of target genes and related pathways were analyzed and screened using the Database for Annotation, Visualization and Integrated Discovery, and the component/target/pathways network of antihepatoma effect of Rubia cordifolia L. was constructed using Cytoscape software. Finally, 16 active compounds were screened from Rubia cordifolia L., and 39 gene targets, including AKT1, mitogen-activated protein kinase 1, and epidermal growth factor receptor, were involved. Rubia cordifolia L. also affected the hepatitis B, phosphoinositide-3-kinase-protein kinase B, and mitogen-activated protein kinase signaling pathways. Many direct-acting tumor-related signaling pathways and indirect-acting hepatitis pathways inhibit the generation of liver cancer. The present study provided a scientific basis for further elucidating the mechanism of Rubia cordifolia L. against liver cancer.

Rubipodanin B, a New Cytotoxic Cyclopeptide from Rubia podantha.

Using the TLC cyclopeptide protosite detection method, a new cyclohexapeptide named rubipodanin B (1), together with 11 known Rubiaceae-type cyclopeptides (RAs), RA-X-OMe (2), RA-IV (3), RA-XI (4), RA-XIII-OMe (5), rubiyunnanin C (6), RA-I (7), RA-III (8), RA-V (9), RA-VII (10), RA-XII (11) and rubipodanin A (12), were obtained from the roots and rhizomes of Rubia podantha Diels. The structures were determined using various spectroscopic methods. Among them, 2 was firstly identified as a natural product, and 3-6 were firstly isolated from this species. Cytotoxicity and NF-κB signaling pathway activity of 1, 2, 4, 6, 7 and 9 were evaluated. All these compounds showed cytotoxic activities against three human tumor cell lines, MDA-MB-231, SW620 and HepG2, with the IC50 values between 0.015 and 10.27 µm, and only 7 and 9 possessed NF-κB inhibitory activities with the IC50 values of 2.42 and 0.046 µm, respectively, which demonstrated that 2-alanine amino acid plays a key role to maintain the RAs bioactivity.

Compositional and Micro-Morphological Characterisation of Red Colourants in Archaeological Textiles from Pharaonic Egypt.

When the imagination conjures up an image of an Egyptian mummy, it is normally one of a human body wrapped with undyed linen bandages. However, the reality was much more colourful, as shown by the set of red mummy shrouds and textile fragments from Pharaonic Egypt considered in this work. The textiles were subjected to scientific investigation with the main aim of shedding light on the sources of red colour and on the possible reasons for the different levels of colour fading. The red colourants were investigated using various non-invasive and micro-invasive approaches. The results pointed towards the presence of three sources of red colour, which, in increasing order of lightfastness, are safflower (Carthamus tinctorius), madder (Rubia spp.), and red ochre. Micro-morphological observations and elemental analyses also enabled some hypotheses to be formulated regarding the application of these colourants to the textiles. The results not only deepen our knowledge of dyeing technologies in ancient Egypt and shed new light on the function of red shrouds and textiles as part of the funerary practices of Pharaonic Egypt, but are also essential in planning the display and future preservation of these mummies and their associated textiles.

NMR-Based Investigation of Hydrogen Bonding in a Dihydroanthracen-1(4 H)one from Rubia philippinensis and Its Soluble Epoxide Hydrolase Inhibitory Potential.

Hydrogen bonding is a vital feature of a large ensemble of chemical structures. Soluble epoxide hydrolase (sEH) has been targeted for development of the treatment for inflammation-associated diseases. Compounds 1 and 2 were purified from Rubia philippinensis, and their structures were established via physical data analysis. Compound 1 possesses intramolecular hydrogen bonding, sufficiently robust to transfer heteronuclear magnetization via a nonbonded interaction. The bonding strength was assessed using the 1H NMR chemical shift temperature coefficients (-1.8 ppb/K), and the heteronuclear coupling constants were measured. The stereochemical details were investigated using interproton distance analysis and ECD. Purified compounds displayed moderate sEH-inhibitory activity.

Cytotoxic properties of the anthraquinone derivatives isolated from the roots of Rubia philippinensis.

BACKGROUND: Cancer is one of the most frequently occurring diseases and is the second leading cause of death worldwide. In this study, anthraquinone derivatives (Compounds 1-5) were evaluated for their anti-cancer potential against various skin and breast cancer cell lines to assess whether these anthraquinone derivatives may serve as a lead for the augmentation of anti-cancer drug. METHODS: Anthraquinone derivatives, 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone-3-O-(6'-O-acetyl)-α-rhamnosyl(1 → 2)-ß-glucoside (Comp 1), 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone (Comp 2), and alizarin (Comp 3) were isolated from the dichloromethane fraction of the roots of Rubia philippinensis., whereas ethyl acetate fraction yielded xanthopurpurin (Comp 4) and lucidin-ω-methyl ether (Comp 5). Structures of all the isolated compounds were determined by spectral data analysis. All isolated compounds (Comp 1-5) were assessed for cytotoxicity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against four different cancer cell lines, i.e. human melanoma (SK-MEL-5), murine melanoma (B16F10), and human breast adenocarcinoma (MCF7 and MDA-MB-231). RESULTS: Significant activity of the compounds 4 and 5 was observed against the breast cancer cell line MDA-MB-231 with IC50 values of 14.65 ± 1.45 and 13.03 ± 0.33 µM, respectively. Encouragingly, IC50 values of 67.89 ± 1.02 and 79.01 ± 0.03 µM against normal kidney epithelial cells (MDCK) were also obtained for compounds 4 and 5, respectively, which indicated very low toxicity and favorable selectivity indices for compounds 4 and 5 in the range of 1.85 to 3.95 and 2.11 to 6.06 against skin cancer cell lines (SK-MEL-5, and B16F10), and breast cancer cell lines (MCF7 and MDA-MB-231), respectively. CONCLUSION: Our results suggested that the compounds 4 (xanthopurpurin) and 5 (lucidin-ω-methyl ether) showed high selective toxicity towards breast cancer cells at lower concentrations without showing toxicity towards normal cells, thus could be of potential as new lead molecules in cancer treatment.

Anti-diarrheal and anti-inflammatory activities of aqueous extract of the aerial part of Rubia cordifolia.

BACKGROUND: In Shaanxi province, China, the aqueous extract of Rubia cordifolia's aerial part (AERCAP) is traditionally used to manage diarrhea. However, there is no scientific evidence to verify the safety and efficacy of its use. The aim of this study was to investigate the anti-diarrheal and anti-inflammatory effects of AERCAP by using a rodent model. METHODS: The anti-diarrheal effects were studied by senna leaf-induced diarrheal and intestinal transit experiments in mice. The anti-inflammatory activity was investigated by trinitrobenzenesulfonic acid (TNBS)-induced colonic inflammation in rats. RESULTS: The results indicated that AERCAP delayed the onset of semi-solid feces, reduced the evacuation index (EI) in senna leaf-induced diarrheal in mice, and inhibited the propulsive movement in castor oil-induced intestinal transit but not in the normal intestinal transit test. The results were compared with the standard anti-diarrheal drug loperamide. Additionally, oral treatment with AERCAP significantly decreased the macroscopic damage area, improved the microscopic structure, and reduced the malondialdehyde (MDA) content, IL-1ß and TNF-α levels in colonic tissue compared with the TNBS control group in rats. CONCLUSIONS: AERCAP exhibited anti-diarrheal and anti-inflammatory activities in a rodent model. The study validated the traditional use of the plant in Chinese herbal medicine as a valuable natural remedy for the treatment of diarrhea.

In vitro and in vivo inhibitory effects of 6-hydroxyrubiadin on lipopolysaccharide-induced inflammation.

Inflammation is a defensive response against a multitude of harmful stimuli and stress conditions such as tissue injury, and is one of the most common pathological processes of human diseases. 6-Hydroxyrubiadin, an anthraquinone isolated from Rubia cordifolia L., exhibits several bioactive properties. The aim of this study was to evaluate whether 6-hydroxyrubiadin can reduce the production of pro-inflammatory cytokines and ameliorate acute lung injury (ALI) in a mouse model. In this study, we demonstrated that 6-hydroxyrubiadin suppressed lipopolysaccharide (LPS)-induced nuclear factor-kappa B activation as well as the phosphorylation of c-Jun N-terminal kinase in RAW 264.7 macrophages. In addition, we also showed that 6-hydroxyrubiadin inhibited the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 in phorbol myristate acetate (PMA)-primed U937 and RAW 264.7 cells. Furthermore, 6-hydroxyrubiadin treatment reduced the production of these cytokines in vivo and attenuated the severity of LPS-induced ALI. Thus, these results suggested that 6-hydroxyrubiadin may be a potential therapeutic candidate for the treatment of inflammation and inflammatory diseases.

UPLC-QTOF-MS Identification of the Chemical Constituents in Rat Plasma and Urine after Oral Administration of Rubia cordifolia L. Extract.

An effective ultra-performance liquid chromatography coupled with the quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS) method was developed for analysing the chemical constituents in rat plasma and urine after the oral administration of Rubia cordifolia L. extract. Under the optimized conditions, nine of 11 prototypes in rat plasma and four prototypes in urine were identified or characterized by comparing the retention time, accurate mass, fragmentation patterns, reference compounds, and literature data. In total, six metabolites, including alizarin-1-O-ß-glucuronide, alizarin-2-O-ß-glucuronide, alizarin-1-O-sulfation, alizarin-2-O-sulfation, purpurin-1-O-ß-glucuronide, and purpurin-3-O-ß-glucuronide, were identified in rat plasma, which were confirmed by lavaging standard solutions. Purpurin was found to be able to be transformed into alizarin based on the results in which alizarin was detected in rat plasma after the oral administration of a purpurin solution. In total, four metabolites were found in rat urine, but their chemical structures were not confirmed. The results indicate that the metabolic pathway of alizarin involves glucuronidation and sulfation, with the purpurins having undergone glucuronidation. The components absorbed into the blood, and the metabolites have the opportunity to become bioactive constituents. The experimental results would supply a helpful chemical basis for further research on the mechanism of actions of Rubia cordifolia L.

[Changes of chemical constituents in Rubiae Radix et Rhizoma before and after carbonized by UPLC-Q-TOF-MS method].

In order to explore the effect on chemical constituents after carbonized, the changes of chemical constituents in raw and carbonized Rubiae Radix et Rhizoma were analyzed by UPLC-Q-TOF-MS. The research also used principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) for data statistics to find out the main differences on components before and after carbonized. The accurate m/z values of Q-TOF-MS and Q-TOF-MS-MS fragments were applied to identify the structures. The results showed that 6 more discrepant constituents were existed between raw and carbonized Rubiae Radix et Rhizoma. Three constituents were selected as the main discrepant components according to the peak area (276 nm) and identified, as lucidin, xanthopurpurin and 1,3,6-trihydroxy-2-methylanthraquinone. After carbonized, contents of xanthopurpurin and 1,3,6-trihydroxy-2-methylanthraquinone were observably increasing, while lucidin was obviously decreasing. They could be used as the chemical markers for the differentiation between raw and carbonized Rubiae Radix et Rhizoma. The results of this experiment played an important role in the study of processing principle of carbonized Rubiae Radix et Rhizoma. It also provided important evidences for the interpretation of effective material based on carbonized Rubiae Radix et Rhizoma.

[Protective effect of different polar fractions of Carbonized Rubiae Radix et Rhizoma (cRRR) against oxidative injury].

The protective effect of different polar fractions of Carbonized Rubiae Radix et Rhizoma (cRRR) against ox-LDL-induced damage to human umbilical vein endothelial cells (HUVECs) was investigated by MTT assay, and the components were identified by using UPLC-Q-TOF-MS. According to the study, ethyl acetate extract and n-butanol extract could increase cell viability (P<0.01), while petroleum ether extract had no influence, and water extract could even inhibit the cell viability to some degree. Moreover, 32 compounds in four polar fractions were analyzed, including 31 quinones and their glycosides, and one rubiprasins C. Petroleum ether extract, ethyl acetate extract, n-butanol extract and water extract contained 23, 32, 26, 15 compounds, respectively. According to cell experiments in vitro, active fractions were ethyl acetate extract and n-butanol extract. The results could provide scientific references for further studies on effective material basic of cRRR, and lay a foundation for studies on the relationship between efficacies and materials.