Flos Chrysanthemi Indici protects against hydroxyl-induced damages to DNA and MSCs via antioxidant mechanism

Closed fixed-bed bacteria-algae biofilm reactor: A promising solution for phenol containing wastewater treatment and resource transformation

This study focuses on treating phenolic wastewater with a novel closed fixed-bed bacteria-algae biofilm reactor (CF-BABR) to enhance resource transformation for phenolic substances. The CF-BABR showed strong impact - load resistance and stable degradation efficiency, fully degrading phenolic compounds at concentrations from 0 to 150 mg/L. From the inflow to the outflow, the effective sequences, abundance, and diversity of bacteria decreased. Chlorobaculum was the dominant bacterium for phenolic pollutant degradation. The abundance of fungi decreased gradually, while their diversity increased. Kalenjinia and Cutaneotrichosporon played a synergistic role in reducing pollutant toxicity. The high - concentration pollutants at the influent led to a higher abundance of microalgal communities, and Scenedesmaceae became the most dominant algal family, which was positively correlated with the degradation of phenolic compounds. Functional gene prediction indicated that the abundance of functional genes in bacteria decreased overall along the wastewater flow. Carbohydrate metabolism and amino acid metabolism were the most active secondary pathways. In fungi, the predicted gene functions had the highest abundance in the upstream region. Metabolic intermediates such as organic acids and derivatives, lipids and lipid - like molecules, and carboxylic acids and derivatives demonstrated the degradation effect of CF-BABR on phenolic compounds.

Aerobic biofilm systems outperform anaerobic and anoxic regimes in 2,4-dimethylphenol degradation: Microbial synergy and metabolic mechanisms

The efficient biodegradation of 2,4-dimethylphenol (2,4-DMP), a toxic and recalcitrant phenolic pollutant, remains a critical challenge in wastewater treatment, with ongoing debate regarding the optimal dissolved oxygen (DO) regime for biofilm-based systems. To resolve this, four biofilm reactors-anaerobic (R1), anoxic (R2), microaerobic (R3), and aerobic (R4)-were operated under a DO gradient (0.3-8.0 mg/L). When influent 2,4-DMP concentrations increased from 25 to 300 mg/L, removal efficiencies declined significantly in R1-R3 (9.0 %, 44.8 %, and 58.8 %, respectively), whereas R4 maintained 100 % removal regardless of loading. Rapid degradation occurred within 8-16 h in R4, correlating with DO consumption from 8.0 to 5.0 mg/L. Aerobic conditions eliminated dependence on extracellular polymeric substances (EPS) for pollutant sequestration, as complete mineralization negated intermediate accumulation. Microbial analysis revealed Zoogloea (18.92 % abundance), Prosthecobacter, and Ferruginibacter as keystone aerobic bacteria, encoding aromatic ring-hydroxylating dioxygenases (RHDs) for 2,4-DMP hydroxylation and β-ketoadipate pathway activation. Concurrently, fungal genera Cutaneotrichosporon (74.50 %) and Kalenjinia were enriched in R4, contributing laccase-mediated ring cleavage. Synergy between bacterial oxidative pathways and fungal ligninolytic systems enabled sustained COD removal (95.54 %) without biofilm destabilization. These findings conclusively demonstrate aerobic biofilms' superiority in 2,4-DMP treatment, driven by metabolic completeness, energy-efficient respiration, and cross-kingdom functional partitioning.

Optimization of extraction and enrichment process of cannabidiol from industrial hemp and evaluation of its bioactivity

Introduction

The Cannabis Sativa L., a perennial dioecious herb renowned for its industrial applications, serves as the source of hemp. Cannabidiol (CBD), a non-psychotropic compound derived from industrial hemp, has garnered considerable interest due to its promising therapeutic potential.

Methods

The extraction parameters for CBD from industrial hemp were optimized using the Box-Behnken design and response surface methodology (RSM). The purification process involved characterizing the penetration and desorption profiles of CBD on HPD-100 resin. The in vitro antibacterial activity was assessed by determining the minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli. Antioxidant properties were evaluated using DPPH and ABTS assays, as well as an iron-reducing ability test.

Results

After optimization, the extraction rate of CBD reached 0.26 ± 0.02%. The use of HP-100 resin in the purification process resulted in a significant enrichment of CBD content, which was 4.2 times higher than that of the crude extract, with a recovery rate of 83.13%. The MIC against S. aureus was found to be 5 mg/mL, while no inhibitory effect was observed against E. coli. The IC50 values for the DPPH and ABTS assays were 0.1875 mg/mL and 2.988 mg/mL, respectively, indicating the potent antioxidant capacity of CBD. Additionally, CBD demonstrated a strong iron-reducing ability.

Conclusion

These findings contribute to the development of CBD for broader applications in various industries, highlighting its potential as a valuable compound in health and wellness sectors.

The stabilization mechanism of the pea protein and rutin complex at the gas/liquid interface and its application in low-fat cream

The objective of this study was to substitute partially fat with pea protein isolate (PP)/rutin (Ru) complexes to produce a healthy and stable low-fat whipped cream. Ru enhanced the foam properties of PP. The Ru binding equivalent was the best at a mass ratio of PP/Ru of 64:4, the PP/Ru complexes particle size was the smallest. The synergistic adsorption of Ru reduced the interfacial tension of the complexes and accelerated their diffusion, permeation, and rearrangement at the air/water interface. The results of rheology and Lissajous plots suggested that PP/Ru complexes functioned as an interfacing stabilizer, enhanced the elastic strength of interface film, and improved the stability of foam. PP/Ru complexes as a fat substitute promoted the aggregation of fat globules and the formation of fat globule network structure. When the substitution rate is 10 %, the texture, stability, and microstructure of the sample are nearly identical to those of full-fat cream.

Optimal harvest period and quality control markers of cultivated Flos Chrysanthemi Indici using untargeted/targeted metabolomics, chemometric analysis and in vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Flos Chrysanthemi Indici (FCI), the flower of Chrysanthemum Indicum L., is a popular traditional Chinese medicine (TCM) for treatment of inflammatory diseases in China. FCI is also a functional food, and is widely used as herbal tea for clearing heat and detoxicating.

AIM OF THE STUDY

To explore quality control markers of FCI based on the optimal harvest period.

MATERIALS AND METHODS

First, UPLC-Q-TOF/MS based untargeted metabolomics was applied to explore the chemical profiles of FCIs collected at bud stages (BS), initial stages (IS), full bloom stages (FS) and eventual stages (ES) from eight cultivated regions in China. Subsequently, lipopolysaccharide (LPS)-induced RAW264.7 cell inflammatory model and carrageenan-induced rat paw edema model were used to confirm the anti-inflammatory effect of FCIs collected at IS/FS. Then, UPLC-PDA targeted metabolomics was used to quantitatively analyze 9 constituents with anti-inflammatory activity (7 flavonoids and 2 phenolic acids) changed significantly (VIP > 4) during flowering stages. Finally, ROC curves combined with PCA analysis based on the variation of 9 active constituents in FCIs from different flowering stages were applied to screen the quality markers of FCI.

RESULTS

FCIs at IS/FS had almost same chemical characteristics, but quite different from those at BS and ES. A total of 32 constituents in FCIs including flavonoids and phenolic acids were changed during flowering development. Most of the varied constituents had the highest or higher contents at IS/FS compared with those at ES, indicating that the optimal harvest period of FCI should be at IS/FS. FCI extract could effectively suppress nitric oxide (NO) production in LPS-induced RAW264.7 cells and regulate the abnormal levels of cytokines and PGE2 in carrageenan-induced paw edema model rat. The results of quantitatively analysis revealed that the variation trends of phenolic acids and flavonoids in FCIs were different during flowering development, but most of them had higher contents at IS/FS than those at ES in all FCIs collected from eight cultivated regions, except one sample from Anhui. Finally, linarin, luteolin, apigenin and 3,5-dicaffeoylquinic acid were selected as the Q-markers based on the contribution of their AUC values in ROC and clustering of PCA analysis.

CONCLUSIONS

Our study demonstrates the optimal harvest period of FCI and specifies the multi-constituents Q-markers of FCI based on the influence of growth progression on the active constituents using untargeted/targeted metabolomics. The findings not only greatly increase the utilization rate of FCI resources and improve quality control of FCI products, but also offer new strategy to identify the Q-markers of FCI.

New Flavan Derivatives from the Leaves and Stems of Cassia Nodosa

Three new flavan derivatives including two methylene-linked flavan-3-ol dimers, bis(8-epiafzelechinyl)methane (1), and 8,8-(epiafzelechin-afzelechin)methane (2), a flavan-3-ol monomer, (-)-3-O-acetyl-epiafzelechin (3) and four known related compounds (4-7) were isolated from the leaves and stems of Cassia nodosa. Their structures were elucidated by extensive spectroscopic analyses and CD data. The isolates were evaluated for their antioxidant, α-glucosidase inhibitory, cytotoxic and neuroinflammatory activities, and compound 3 exhibited remarkable radical scavenging activities in both the DPPH and ABTS models with IC50 values of 2.65±1.25, and 4.78±0.91 μg/mL, respectively.

Which biofilm reactor is suitable for degradation of 2,4-dimethylphenol, focusing on bacteria, algae, or a combination of bacteria-algae?

Effectively treating phenolic substances is a crucial task in environmental protection. This study aims to determine whether bacterial-algae biofilm reactors offer superior treatment efficacy compared to traditional activated sludge and biofilm reactors. The average degradation ratios of 2,4-dimethylphenol (40, 70, 150, 300, and 230 mg/L) were found to be 98 %, 99 %, 92.1 %, 84.7 %, and 63.7 % respectively. The bacterial-algae biofilm demonstrates a higher tolerance to toxicity, assimilation ability, and efficacy recovery ability. The cell membrane of Chlorella in the bacteria-algae biofilm is not easily compromised, thus ensuring a stable pH environment. High concentrations of tightly bound extracellular polymers (TB-EPS) enhance the efficacy in treating toxic pollutants, promote the stable structure. Intact Chlorella, bacilli, and EPS were observed in bacterial-algal biofilm. The structural integrity of bacteria-algae consistently enhances its resistance to the inhibitory effects of high concentrations of phenolic compounds. Cloacibacterium, Comamonas, and Dyella were the main functional bacterial genera that facilitate the formation of bacterial-algal biofilms and the degradation of phenolic compounds. The dominant microalgal families include Aspergillaceae, Chlorellales, Chlorellaceae, and Scenedesmaceae have certain treatment effects on phenolic substances. Chlorellales and Chlorellaceae have the ability to convert NH4+-N. The Aspergillaceae is also capable of generating synergistic effects with Chlorellales, Chlorellaceae, and Scenedesmaceae, thereby establishing a stable bacterial-algal biofilm system.

Effect of dynamic high-pressure microfluidization treatment on soybean protein isolate-rutin non-covalent complexes

In this investigation, soybean protein isolate-rutin (SPI-RT) complexes were treated using dynamic high-pressure microfluidization (DHPM). The effects of this process on the physicochemical and thermodynamic properties of SPI were investigated at different pressures. Fourier-transform infrared spectroscopy and fluorescence spectroscopy provided evidence that the SPI structure had been altered. The binding of SPI to RT resulted in a decrease in the percentage of α-helices and random curls as well as an increase in the percentage of β-sheets. In particular, the α-helix content decreased from 29.84 % to 26.46 %, the random curl content decreased from 17.45 % to 15.57 %, and the β-sheet content increased from 25.37 % to 26.53 %. Moreover, fluorescence intensity decreased, and the emission peak of the complex was red-shifted by 6 nm, exposing the internal groups. Based on fluorescence quenching analysis, optimal SPI-RT complexation was achieved after 120-MPa DHPM treatment, and molecular docking analysis verified the interaction between SPI and RT. The minimum particle size, maximum absolute potential, and total phenolic content of the complexes were 78.06 nm, 21.4 mV and 74.35 nmol/mg protein, respectively. Furthermore, laser confocal microscopy revealed that the complex particles had the best microstructure. Non-covalent interactions between the two were confirmed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Moreover, the hydrophobicity of the complex particle's surface increased to 16,045 after 120-MPa DHPM treatment. The results of this study suggest that DHPM strongly promotes the improvement of the physicochemical properties of SPI, and provide a theoretical groundwork for further research.

Use microalgae to treat coke wastewater for producing biofuel: Influence of phenol on photosynthetic properties and intracellular components of microalgae

Using microalgae to treat coking wastewater has important application prospects and environmental significance. Previous studies have suggested that phycoremediation of pollutants from coking wastewater is feasible and can potentially enhance biodiesel production. This work investigates the effects of phenol in coking wastewater on C. pyrenoidosa and S. obliquus growth, photosynthesis activity, and intracellular components. The results indicated that when the phenol concentration was lower than 300 mg L-1, both microalgae maintained good photosynthetic and physiological activity, with a maximum quantum yield potential ranging from 0.6 to 0.7. At the phenol concentration of 300 mg L-1, the biomass of C. pyrenoidosa was 2.4 times that of the control group. For S. obliquus, at the phenol concentration of 150 mg L-1, the biomass was approximately 0.85 g L-1, which increased by 68% than that of the control group (0.58 g L-1). The lipid content in both microalgae increased with the phenol concentrations, with the maximum content exceeding 40%. The optimal phenol concentrations for C. pyrenoidosa and S. obliquus growth were determined to be 246.18 and 152.73 mg L-1, respectively, based on a developed kinetic model. This work contributes to further elucidating the effects of phenol on microalgae growth, photosynthesis, and intracellular components, and suggests that using microalgae to treat phenol-containing coking wastewater for producing biofuel is not only environmentally friendly but also holds significant energy promise.

Pilot study on ceramic flat membrane bioreactor in treatment of coal chemical wastewater

Some toxic and refractory pollutants in coal chemical wastewater can penetrate the biochemical treatment systems and cause high concentrations of suspended solids in the effluent, which may obstruct the subsequent advanced treatment. In this project, a submerged ceramic plate membrane system was integrated to the last oxic corridor of an existing multistage anoxic/oxic tank. In the ceramic flat membrane bioreactor, the influent chemical oxygen demand (COD) was 102.24-178.88 mg/L, with a removal ratio of approximately 30%. The NH3-N concentration in the effluent was relatively stable with an average value of 1.76 mg/L. The turbidity of the effluent was in the range of 0.235-0.852 NTU and was stable below 1 NTU. A flux of 30 L m-2·h-1 could meet the requirements of the pilot test. A gas-water ratio of 50:1 was found optimal. When the concentration of mixed liquor suspended solids (MLSS) was >3769 mg/L, the extracellular polymeric substance in the mixed solution was utilized by microorganisms as a substrate. High MLSS decreased membrane fouling rate. NaClO backwashing can effectively remove pollutants without adversely affecting the treatment efficiency of membrane bioreactors.

Polyphenol Composition, Antioxidant Capacity and Xanthine Oxidase Inhibition Mechanism of Furong Plum Fruits at Different Maturity Stages

An experiment was conducted on the polyphenol content, flavonoid content, anthocyanin content, and antioxidant capacity of Furong plum (Prunus salicina Lindl. cv. "furong") at different maturity stages to determine the most suitable maturity stage. The inhibition of plum polyphenols on xanthine oxidase (XOD) was measured, and its kinetics were studied to reveal the inhibitory mechanism. The experimental results showed that the polyphenol, flavonoid and anthocyanin contents of plums at the ripe stage were the highest, reaching 320.46 mg GAE/100 g FW, 204.21 mg/100 g FW, and 66.24 mg/100 g FW, respectively, in comparison those of the plums at the immature and mid-ripe stages. The antioxidant capacity of the ripe plums was stronger than it was during the other stages of the plums growth. Among them, the total polyphenols of the ripe plums exhibited the strongest antioxidant capacity (IC50 values against DPPH and hydroxyl radicals were 28.19 ± 0.67 μg/mL and 198.16 ± 7.55 μg/mL, respectively), which was between the antioxidant capacity of the free polyphenols and bound polyphenols. The major phenolic monomer compounds of plum polyphenols were flavan-3-ols (epicatechin, catechin, proanthocyanidin, and procyanidin B2), flavonols (myricetin), and phenolic acids (chlorogenic acid, ferulic acid, and protocatechuic acid). Additionally, plum polyphenols exhibited a strong inhibitory effect on XOD, with an IC50 value of 77.64 μg/mL. The inhibition kinetics showed that plum polyphenols are mixed-type inhibitors that inhibit XOD activity and that the inhibition process is reversible. The calculated values of Ki and α were 16.53 mmol/L and 0.26, respectively.

Fabrication of BODIPY/polyvinyl alcohol/alkaline lignin antibacterial composite films for food packing

Foodborne pathogens seriously endanger people's health and cause significant economic losses. Therefore, it is of great significance to design potent packaging materials with the function of alleviating food spoiling and extending shelf life. Here, three BODIPY derivatives (named as N-BDPI, B-BDPI and P-BDPI) were synthesized by substituting the 8-position of BODIPY with naphthalene, biphenyl and pyridine groups, respectively, and their photophysical properties as well as antibacterial capacities were characterized. The results demonstrated that N-BDPI had the best singlet oxygen generation ability and could completely kill S. aureus under light irradiation with the minimum inhibitory concentration of only 50 nmol/L. In addition, 1.0% BDPI@PVA/AL composite film was fabricated by doping N-BDPI into polyvinyl alcohol (PVA) and alkaline lignin (AL) exhibited high antibacterial activity on Gram-positive bacteria. The coating of strawberries with 1.0% BDPI@PVA/AL film not only effectively inhibited the mildew of strawberries, but also extended their shelf life.

Nanomaterial Size and Surface Modification Mediate Disease Resistance Activation in Cucumber (Cucumis sativus)

Crop disease represents a serious and increasing threat to global food security. Lanthanum oxide nanomaterials (La₂O₃ NMs) with different sizes (10 and 20 nm) and surface modifications (citrate, polyvinylpyrrolidone [PVP], and poly(ethylene glycol)) were investigated for their control of the fungal pathogen Fusarium oxysporum (Schl.) f. sp cucumerinum Owen on six-week-old cucumber (Cucumis sativus) in soil. Seed treatment and foliar application of the La₂O₃ NMs at 20-200 mg/kg (mg/L) significantly suppressed cucumber wilt (decreased by 12.50-52.11%), although the disease control efficacy was concentration-, size-, and surface modification-dependent. The best pathogen control was achieved by foliar application of 200 mg/L PVP-coated La₂O₃ NMs (10 nm); disease severity was decreased by 67.6%, and fresh shoot biomass was increased by 49.9% as compared with pathogen-infected control. Importantly, disease control efficacy was 1.97- and 3.61-fold greater than that of La₂O₃ bulk particles and a commercial fungicide (Hymexazol), respectively. Additionally, La₂O₃ NMs application enhanced cucumber yield by 350-461%, increased fruit total amino acids by 295-344%, and improved fruit vitamin content by 65-169% as compared with infected controls. Transcriptomic and metabolomic analyses revealed that La₂O₃ NMs: (1) interacted with calmodulin, subsequently activating salicylic acid-dependent systemic acquired resistance; (2) increased the activity and expression of antioxidant and related genes, thereby alleviating pathogen-induced oxidative stress; and (3) directly inhibited in vivo pathogen growth. The findings highlight the significant potential of La₂O₃ NMs for suppressing plant disease in sustainable agriculture.

Effects of methanol, sodium citrate, and chlorella powder on enhanced anaerobic treatment of coal pyrolysis wastewater

To better promote environment friendly development of the coal chemical industry, this study investigated effects of methanol, sodium citrate, and chlorella powder (a type of microalgae) as co-metabolic substances on enhanced anaerobic treatment of coal pyrolysis wastewater with anaerobic sludge. The anaerobic sludge was loaded into four 2 L anaerobic reactors for co-metabolism enhanced anaerobic experiments. Anaerobic reactor 1 (R1) as control group did not add a co-metabolic substance; anaerobic reactor 2 (R2) added methanol; anaerobic reactor 3 (R3) added sodium citrate; and anaerobic reactor 4 (R4) added chlorella powder. In the blank control group, the removal ratios of total phenol (TPh), quinoline, and indole were only 12.07%, 42.15%, and 50.47%, respectively, indicating that 50 mg/L quinoline, 50 mg/L indole, and 600 mg/L TPh produced strong toxicity inhibition function on the anaerobic microorganism in reactor. When the concentration of methanol, sodium citrate, and chlorella was 400 μg/L, the reactors with co-metabolic substances had better treatment effect on TPh. Among them, the strengthening effects of sodium citrate (TPh removal ratio: 44.87%) and chlorella (47.85%) were better than that of methanol (38.72%) and the control group (10.62%). Additionally, the reactors with co-metabolic substances had higher degradation ratios on quinoline, indole, and chemical oxygen demand (COD). The data of extracellular polymeric substances showed that with the co-metabolic substances, anaerobic microorganisms produced more humic acids by degrading phenols and nitrogen-containing heterocyclic compounds (NHCs). Compared with the control group, the reactors added with sodium citrate and chlorella had larger average particle size of sludge. Thus, sodium citrate and chlorella could improve sludge sedimentation performance by increasing the sludge particle size. The bacterial community structures of reactors were explored and the results showed that Aminicenantes genera incertae sedis, Levinea, Geobacter, Smithella, Brachymonas, and Longilinea were the main functional bacteria in reactor added with chlorella.

An Investigation of the Anti-Depressive Properties of Phenylpropanoids and Flavonoids in Hemerocallis citrina Baroni

The World Health Organization predicts that over the next several years, depression will become the most important mental health issue globally. Growing evidence shows that the flower buds of Hemerocallis citrina Baroni (H. citrina) possess antidepressant properties. In the search for new anti-depression drugs, a total of 15 phenylpropanoids and 22 flavonoids were isolated and identified based on spectral data (1D and 2D NMR, HR-ESI-MS, UV) from H. citrina. Among them, compound 8 was a novel compound, while compounds 1-4, 6, 9, 10, 15, 17, 24-26, 28, and 37 were isolated for the first time from Hemerocallis genus. To study the antidepressant activity of phenylpropanoids and flavonoids fractions from H. citrina, macroporous resin was used to enrich them under the guidance of UV characteristics. UHPLC-MS/MS was applied to identify the constituents of the enriched fractions. According to behavioral tests and biochemical analyses, it showed that phenylpropanoid and flavonoid fractions from H. citrina can improve the depressive-like mental state of chronic unpredictable mild stress (CUMS) rats. This might be accomplished by controlling the amounts of the inflammatory proteins IL-6, IL-1β, and TNF-α in the hippocampus as well as corticosterone in the serum. Thus, the monomer compounds were tested for their anti-neuroinflammatory activity and their structure-activity relationship was discussed in further detail.

Impact of non-covalent bound polyphenols on conformational, functional properties and in vitro digestibility of pea protein

This study investigated the effects of the non-covalent interaction of pea protein isolate (PPI) with epigallocatechin-3-gallate (EGCG), chlorogenic acid (CA) and resveratrol (RES) on the structural and functional properties of proteins. The conformational changes of the protein structure with EGCG, CA and RES were analyzed using fourier transform infrared spectroscopy. Polyphenols strongly quenched the intrinsic fluorescence of PPI mainly through static quenching. The main interaction force was hydrogen bonding and van der Waals forces for PPI-EGCG, the main interaction force of PPI-CA complex was electrostatic interaction, while RES and PPI were bound by hydrophobic interaction. Free sulfhydryl groups and surface hydrophobicity significantly decreased in PPI after binding with phenolic compounds. The presence of EGCG, CA and RES enhanced the emulsification, foaming and in vitro digestibility of PPI. These results illustrate the potential applications of PPI-polyphenol complexes in food formulations.

Evaluation of coloration, nitrite residue and antioxidant capacity of theaflavins, tea polyphenols in cured sausage

This study evaluated the effects of theaflavins (TFs), tea polyphenols (TP) and vitamin C (VC) on the nitrite residue amount, color, antioxidant capacity and N-nitrosamines inhibition in cured sausage. The addition of TFs, TP and VC combined with NaNO₂ respectively could significantly increase the a* value, nitroso pigment content and DPPH free radical scavenging rate, and effectively reduced the content of residual nitrite, metmyoglobin (MetMb) and total N-nitrosamines in cured sausages than treated only with NaNO₂ (P < 0.05), of which TFs group was the most significant (P < 0.05). It was indicated that the addition of TFs, TP could better inhibit the oxidation of cured sausages. UV-vis spectroscopy also showed pentacoordinate nitrosyl ferrohemochrome was the main pigment component in the samples. The results demonstrated that TFs and TP could contribute to the desired color and safety of sausage.

The evaluation of the chemical quality and UV overall components dissolution consistency of Flos Chrysanthemi Indici preparation

In recent years, new chemical technology and chemical analysis methods have been widely used for the quality control of medicine to provide security for human life. However, for the increasingly popular traditional Chinese medicine (TCM) preparations, the traditional quality control technology has been challenged due the presence of multi-components. To solve this problem, this study proposed a comprehensive evaluation strategy from two aspects: chemical quality and in vitro dissolution consistency. Zhenju antihypertensive tablet (FCIP), as the research object of this study, is a compound preparation of Flos Chrysanthemi Indici with moderate antihypertensive effect. For the chemical quality, the capillary electrophoresis fingerprint (CE-FP) was established based on the characteristic multi-wavelength averaging fusion profiling (CMW-AFP) strategy, which can fuse peaks in the CE chromatogram at several select characteristic wavelengths into one profile through an averaging algorithm. All samples were clarified into 5 quality grades using the systematic quantified fingerprint method, and showed significant difference among the four manufacturers. Combined with the accurate determination of the marker components, the CE-FP evaluation results can provide a guarantee for the chemical quality consistency. For the in vitro dissolution consistency, a UV overall components dissolution method was proposed. Meanwhile, in order to match the established UV overall dissolution system, two f2 factors (f2-R and f2-MI) were calculated to compare the dissolution profiles. By comparing the chemical and UV overall dissolution results plus the PCA analysis, the holistic quality of the FCIP samples of four manufacturers were obtained as MA > MC > MD > MB. The established evaluation system is also a suitable strategy for controlling the chemical quality and dissolution consistency of other TCM preparations.

Anti-inflammatory chemical constituents of Flos Chrysanthemi Indici determined by UPLC-MS/MS integrated with network pharmacology

Flos Chrysanthemi Indici (FCI), the flower of Chrysanthemum indicum L., is a common functional food and a well-known traditional Chinese medicine (TCM) for the treatment of inflammatory diseases. Previous studies have revealed that FCI has anti-inflammatory activity, but little is known about its anti-inflammatory chemical profile. In this study, the potential anti-inflammatory constituents of FCI were investigated by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with the network pharmacology approach, and further confirmed on a LPS activated RAW264.7 macrophage model. As a result, a total of forty-two compounds, including thirty-two flavonoids, nine phenolic acids and one sesquiterpene, were identified. Among them, fourteen compounds including eight flavonoids (11, 17, 24, 28, 32, 39, 41 and 42) and six caffeoylquinic acids (3, 4, 5, 13, 15 and 20) were recognized as potential key anti-inflammatory constituents of FCI through network pharmacology analysis, because they accounted for 92% of the relative peak area in the UPLC-Q-TOF/MS chromatogram and acted on 87 of 97 the inflammatory targets of FCI. However, only 16 targets were shared between the flavonoids and caffeoylquinic acids, indicative of both acting on more different targets. Further the anti-inflammatory effects of the fourteen constituents were validated with the decreased levels of NO, TNF-α, IL-6 and PGE2 in RAW264.7 macrophage cells treated with LPS. Our results indicated that both flavonoids and caffeoylquinic acids were responsible for the anti-inflammatory effect of FCI through synergetic actions on multi-targets. Moreover, 3,5-dicaffeoylquinic acid (15), luteolin (24) and linarin (28) were the most important active constituents of FCI and could be selected as chemical markers for quality control of FCI. Overall, the findings not only explore the anti-inflammatory chemical constituents of FCI, but also provide novel insights into the effective constituents and mechanism of TCMs.

Conformational changes and functional properties of whey protein isolate-polyphenol complexes formed by non-covalent interaction

The present study was conducted to evaluate the non-ovalent modifications of whey protein isolate (WPI) with gallic acid (GA), chlorogenic acid (CA) and epigallocatechin gallate (EGCG). The structural and functional properties of WPI before and after binding with GA, CA and EGCG were investigated. Results showed that free sulfhydryl groups and surface hydrophobicity significantly decreased in WPI after binding with phenolic compounds. Significant structural alterations in complexes were demonstrated, characterized by a red-shifted maximum emission wavelength in intrinsic fluorescence spectroscopy, and a significant decrease in α-helix and β-sheet and a remarkable increase in β-turn and random coil contents in fourier transform infrared (FTIR) spectroscopy. Moreover, the presence of three polyphenols induced enhanced solubility, foaming and emulsifying capacities of WPI. These findings suggest the feasible application of GA, CA and EGCG to improve the functional properties of WPI and the potential uses of WPI-polyphenol complexes in food industries.

The analysis of active compounds in Flos Chrysanthemi Indici by UHPLC Q exactive HF hybrid Quadrupole-Orbitrap MS and comprehensive quality assessment of its preparation

Flos Chrysanthemi Indici (FCI) is a common food and its preparation (FCIP) is generally made to realize the medicinal value of FCI in a more accurate and controllable way. In this paper, an efficient UHPLC Q Exactive HF Hybrid Quadrupole-Orbitrap MS method was exploited to elucidate the difference of chemical components between FCI and FCIP. Multi-fingerprints (HPLC-FP, UV-FP, and DSC-FP) were established with the evaluation results integrated by a weighted mean algorithm using variation coefficient (CVWM), which is more objective and reasonable. Through this method, the quality grades of 25 FCIP samples from four manufacturers were successfully discriminated. Meanwhile, the PLS model for the profile-efficacy relationship between the HPLC-FP and the antioxidant activities was established, as well as the correlation between the antioxidant ability (IC50) and the DSC curve (enthalpy values) were preliminary explored. In conclusion, this study provides a novel and holistic analytical strategy for food herbal remedies and its preparation.

Herbal Medications Used to Treat Fever

Fever is a natural body defense and a common symptom of disease. Herbs have been used for thousands of years to treat fever. Many herbs have anti-inflammatory properties. Some are useful in reducing the release of cytokines and mediators of inflammation, whereas others work as natural aspirins to inhibit cyclooxygenase. In addition, herbs have known antipathogenic properties and can be effective in the treatment of infection from numerous microorganisms. Last, in traditional Chinese medicine, herbs are used to restore imbalances between the nonpathogenic and the pathogenic clearing interior heat and treating heat patterns in a variety of ways.

Ecological and functional research into microbiomes for targeted phenolic removal in anoxic carbon-based fluidized bed reactor (CBFBR) treating coal pyrolysis wastewater (CPW)

Powdered activated carbon (PAC), lignite activated coke (LAC) and Fe-C carriers were applied to enhance CBFBRs to degrade targeted phenolics. In start-up stage, PAC and LAC equipped CBFBRs with higher environment adaptability and phenolic degradation capacity for phenol (>96%), p-cresol (>91%) and 3, 5-dimethylphenol (>84%) in comparison to Fe-C carrier. In recovery stage, the superior performance was also identified for CBFBRs in basis of PAC and LAC than Fe-C-based reactor. However, the Fe-C carrier assisted CBFBR with more stable degradation performance under impact loading. By comparing microbiomes, significantly enriched Brachymonas (54.80%-68.81%) in CBFBRs exerted primary role for phenolic degradation, and positively contributed to microbial network. Meanwhile, Geobacter in Fe-C-based reactor induced excellent impact resistance by enhancing interspecific electron transfer among microbes. Furthermore, the investigation on functional genes related to phenolic degradation revealed that anaerobic pathway accounted for demethylation procedure, while aerobic pathways dominated the phenolic ring-cleavage process.

Cultivated Fruit Body of Phellinus baumii: A Potentially Sustainable Antidiabetic Resource

Previous studies have been reported that the fruit body of wild Phellinus baumii alleviates diabetes, and antioxidants are beneficial to diabetes by protecting the β-cell from damage due to oxidative stress. Large-scale cultivation of P. baumii fruit body has been successful in the past decade. This paper aimed to investigate whether the fruit body of the cultivated P. baumii has the same analogical effects as the wild. The cultivated P. baumii fruit body was extracted by 80% of ethanol extracts, and different fractions were obtained with the successive use of petroleum ether, ethyl acetate (EtOAc), n-butanol (n-BuOH), and water, which yielded 15.98 ± 1.56, 1.74 ± 0.34, 3.31 ± 0.41, 4.12 ± 0.37, and 1.38 ± 0.26% extract recovery, respectively. Results show that the EtOAc fraction exhibits the highest inhibitory effect on α-glucosidase activity (IC50 = 49.05 ± 3.14 μg mL-1), which is an order of magnitude higher than the positive control (acarbose, IC50 = 645.73 ± 7.86 μg mL-1). It was mainly composed of phenolic compounds with a purity of 79.45% and characterized by liquid chromatography-mass spectrometry as osmudacetone, hispidin, davallialactone, 2,5-bis(4,7-dihydroxy-8-methyl-2-oxo-2H-chromen-3-yl)cyclohexa-2,5-diene-1,4-dione, hypholomin B, and inoscavin A. Furthermore, the EtOAc fraction increased the glucose consumption of insulin-resistant HepG2 cells at a concentration range of 25-100 μg mL-1. The EtOAc fraction also demonstrated antioxidant activities by scavenging 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt, and hydroxyl radicals. In conclusion, the EtOAc fraction of the cultivated P. baumii fruit body exerted effective antidiabetic effects, possibly due to the high content of selective phenolic compounds. Hence, the cultivated fruit body of P. baumii can be a sustainable resource for treating diabetes, and our work also shed some light on its future utilization.

In vitro prebiotic activities of oligosaccharides from the by-products in Ganoderma lucidum spore polysaccharide extraction

Until recently, a variety of oligosaccharides from fruits, vegetables and mushrooms have demonstrated positive prebiotic effects. Ganoderma lucidum, a well-known traditional medicine and tonic in East Asia, has been utilized in the prevention and treatment of a broad range of illnesses. In this study, each of three oligosaccharides was obtained from the polysaccharide extraction by-products of sporoderm: the unbroken and broken spores of Ganoderma lucidum (UB-GLS, B-GLS). Their molecular weight distribution, monosaccharide composition and preliminary structures were analyzed using gel permeation chromatography (GPC), GC-MS, UV and FTIR, respectively. All of the oligosaccharides were found to exhibit prebiotic activities, evaluated by detecting growth stimulation on Lactobacillus in vitro. Among these, UB-O80 and B-O80 displayed the most significant effects (p < 0.05) in these groups, and UB-O80 showed higher resistance to hydrolysis by artificial human gastric juice compared with inulin, giving a maximum hydrolysis rate of 1.65%. Compared with inulin media, Lactobacillus also revealed high tolerance to lower pH levels and simulated gastric juices in UB-O80 and B-O80 media. Compared with a control in gut microbiota fermentation, the abundance of some beneficial bacteria increased and some harmful bacteria declined in the groups of UB-O80 and B-O80. In conclusion, the results suggest that GLS oligosaccharides could be exploited as promising prebiotics for the enhancement of human health.

Until recently, a variety of oligosaccharides from fruits, vegetables and mushrooms have demonstrated positive prebiotic effects.

DNA Binding Characteristics and Protective Effects of Yellow Pigment from Freshly Cut Yam (Dioscorea opposita)

Yam yellow pigments (YP) are natural pigments formed during the storage of freshly cut yam (Dioscorea opposita) under certain conditions. The interaction of YP with calf thymus DNA (ctDNA) and its protective effect against DNA oxidative damage were investigated using multiple spectroscopic techniques, competitive binding experiments, viscosity measurements, and gel electrophoresis. Results showed that YP participated in intercalative binding with ctDNA. YP exhibited a protective effect against hydroxyl-induced DNA damage, which was attributed to the high hydroxyl radical scavenging activity of YP. Our findings improve our understanding of the mechanism of interaction between YP and ctDNA, and provide a theoretical basis for the application of YP in the food and drug industry.

Enhanced biodegradation of coal gasification wastewater with anaerobic biofilm on polyurethane (PU), powdered activated carbon (PAC), and biochar

The primary objective was to explore the feasibility of anaerobic biofilm on polyurethane (PU), powdered activated carbon (PAC), and biochar in strengthening anaerobic degradation of phenolic compounds and selected nitrogen heterocyclic compounds (NHCs) in coal gasification wastewater (CGW). When total phenols (TPh) was less than 300 mg/L, PAC-based biofilm was more efficient. Whereas, when the TPh concentration was more than 450 mg/L, PU-based biofilm performed the optimal degradation efficiency. Furthermore, microbial community structure analysis showed that PAC and biochar had little effect on the microbial community structure after 120 days of operation, while the addition of PU could lead to the enrichment of Giesbergeria, Caldisericum, Thauera, Methanolinea, and Methanoregula.

Comparative investigation on carbon-based moving bed biofilm reactor (MBBR) for synchronous removal of phenols and ammonia in treating coal pyrolysis wastewater at pilot-scale

By regulating the extraction solvent and alkali in pretreatment, two carbon-based MBBRs were compared in pilot-scale to synchronously remove phenols and ammonia of coal pyrolysis wastewater (CPW) under fluctuant phenols-ammonia loadings. It revealed that lignite activated coke (LAC)-based MBBR performed more stable with phenols increasing (250-550 mg/L), and reached higher tolerance limit to ammonia (>320 mg/L) than activated carbon (AC)-based MBBR under fluctuant ammonia loadings. During the phenols-ammonia synchronous removal process, the LAC provided the firm basis for shock resistance due to superior resilient adsorption capacity, enhanced sludge property and microbial cooperation. Furthermore, microbial analysis revealed that the strengthened collaboration between archaea and facultative bacteria played the primary role in phenols-ammonia synchronous degradation. Specifically, the heterotrophic bacteria consumed phenols-ammonia by partial nitrification process and ammonia assimilation, following by denitrifying process to further eliminate phenols. The multifunctional Comamonas was the critical genus participating in all procedures.

The fucoidan A3 from the seaweed Ascophyllum nodosum enhances RCT-related genes expression in hyperlipidemic C57BL/6J mice

Reverse cholesterol transport (RCT) has been demonstrated to reduce hyperlipidemia, and fucoidans are found to possess hypolipidemic effect. This study was designed to investigate the lipid-lowering effect of the fucoidan from the brown seaweed A. nodosum and whether it improves RCT-related genes expression in C57 BL/6J mice. Our results indicated that fucoidan A3 (100 mg/kg/day) intervention significantly reduced plasma total cholesterol (~23.2%), triglyceride (~48.7%) and fat pad index. This fucoidan significantly increased the mRNA expression of low-density lipoprotein receptor (LDLR), scavenger receptor B type 1 (SR-B1), cholesterol 7 alpha-hydroxylase A1 (CYP7A1), liver X receptor (LXR) β, ATP-binding cassette transporter (ABC) A1 and sterol regulatory element-binding protein (SREBP) 1c, and decreased the expression of peroxisome proliferator-activated receptor (PPAR) γ, however, it had no effect on the expression of proprotein convertase subtilisin/kexin type 9, PPARα, LXRα, SREBP-2, ABCG1, ABCG8 and Niemann-Pick C1-like 1. These results demonstrated that this fucoidan improved lipid transfer from plasma to the liver by activating SR-B1 and LDLR, and up-regulated lipid metabolism by activating LXRβ, ABCA1 and CYP7A1. In conclusion, this fucoidan lowers lipid by enhancing RCT-related genes expression, and it can be explored as a potential candidate for prevention or treatment of lipid disorders.

Synergistic degradation on phenolic compounds of coal pyrolysis wastewater (CPW) by lignite activated coke-active sludge (LAC-AS) process: Insights into succession of microbial community under selective pressure

This study illustrated synergistic degradation of phenolic compounds by LAC-AS process via the insight into succession of microbial community under selective pressure. The results demonstrated that high phenols exhibited toxicity pressure to single AS process by eliminating non-tolerate bacteria, inducing vicious circulation by intermediates (catechol, nitrate, etc.) accumulation. However, LAC exerted another selective pressure and facilitated positive bio-community succession of moving biological bed reactor (MBBR). Firstly, it created rich microenvironments for diverse bacteria and promoted resilient adsorption for phenols with the assistance of biodegradation. Secondly, LAC enriched facultative bacteria, which developed multiple degradation paths on phenols and nitrogen based on multifunctional genes, counteracting the toxicity pressure. Specifically, phenols were degraded by the combination of anaerobic hydrolysis and oxidation, while conventional and shortcut nitrification-denitrification (SND) and nitrogen fixation all participated in nitrogen removal, achieving high removal of COD (93.49%), Tph (93.74%), TN (92.20%) and NH₄⁺-N (93.20%) under the highest phenols.

A Null B-Ring Improves the Antioxidant Levels of Flavonol: A Comparative Study between Galangin and 3,5,7-Trihydroxychromone

To clarify the role of the B-ring in antioxidant flavonols, we performed a comparative study between galangin with a null B-ring and 3,5,7-trihydroxychromone without a B-ring using five spectrophotometric assays, namely, ^•O₂^--scavenging, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•)-scavenging, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical-scavenging, 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical-scavenging, and Fe³⁺-reducing activity. The DPPH^•-scavenging reaction products of these assays were further analyzed by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technology. In the five spectrophotometric assays, galangin and 3,5,7-trihydroxychromone dose-dependently increased their radical-scavenging (or Fe³⁺-reducing) percentages. However, galangin always gave lower IC₅₀ values than those of 3,5,7-trihydroxychromone. In the UPLC-ESI-Q-TOF-MS/MS analysis, galangin yielded galangin-DPPH adduct MS peaks (m/z 662, 434, 301, 227,196, and 151) and galangin-galangin dimer MS peaks (m/z 538, 385, 268, 239, 211, 195, and 151). 3,5,7-Trihydroxychromone, however, only generated m/z 3,5,7-trihydroxychromone-DPPH adduct MS peaks (m/z 586, 539, 227, 196, and 136). In conclusion, both galangin and 3,5,7-trihydroxychromone could similarly undergo multiple antioxidant pathways, including redox-dependent pathways (such as electron transfer (ET) and ET plus proton transfer (PT)) and a non-redox-dependent radical adduct formation (RAF) pathway; thus, the null B-ring could hardly change their antioxidant pathways. However, it did improve their antioxidant levels in these pathways. Such improvement of the B-ring toward an antioxidant flavonol is associated with its π-π conjugation, which can provide more resonance forms and bonding sites.

Steric Effect of Antioxidant Diels-Alder-Type Adducts: A Comparison of Sanggenon C with Sanggenon D

Sanggenons C and D are two Diels-Alder-type adducts from Chinese crude drug Sang-bai-pi. Structurally, both sanggenons construct stereoisomers. In the study, they were comparatively determined using four antioxidant assays, including ferric ion reducing antioxidant power (FRAP) assay, Cu²⁺-reducing assay, 1,1-diphenyl-2-picryl-hydrazl (DPPH•)-scavenging assay, and 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid radical (ABTS•⁺)-scavenging assay. Their Fe²⁺-binding reactions were explored using UV-Vis spectra. Finally, their cytoprotective effects were evaluated using flow cytometry. In electron transfer (ET)-based FRAP and Cu²⁺-reducing assays, sanggenon D was found to have lower IC₅₀ values than sanggenon C; however, in multi-pathway-based DPPH•-scavenging and ABTS•⁺-scavenging assays, sanggenon C possessed lower IC₅₀ values than sanggenon D. UV-Vis spectra suggested that sanggenon C generated a bathochromic-shift (286 nm → 302 nm) and displayed stronger UV absorption than sanggenon D. In flow cytometry, sanggenon C and sanggenon D, respectively, exhibited 31.1% and 42.0% early apoptosis-percentages towards oxidative-stressed mesenchymal stem cells (MSCs). In conclusion, both sanggenons may undergo multiple pathways (e.g., ET and Fe²⁺-binding) to protect MSCs against oxidative stress. In the mere ET aspect, sanggenon D possesses a higher level than sanggenon C, while in multi-pathway-based radical-scavenging, Fe²⁺-binding, and cytoprotection aspects, sanggenon C is more active than sanggenon D. These discrepancies can conclusively be attributed to the steric effect.

Flos Chrysanthemi Indici extract improves a high-sucrose diet-induced metabolic disorder in Drosophila

Flos Chrysanthemi Indici (CI) is a traditional medicinal plant used in the treatment of inflammatory diseases. However, the pharmacological role of CI in metabolic diseases, especially in diseases induced by insulin metabolism disorders, remains poorly understood. In the present study, Drosophila melanogaster (Drosophila) were fed with high-sugar diet (HSD) to induce a model similar to Type 2 diabetes (T2D) in order to determine whether CI extracts improve the metabolic disorder. It was demonstrated that the CI extracts could improve growth rate, body size, lifespan, reproductive capacity and fat storage, and CI especially improved the fat metabolism and cell size in S6k and Akt1 mutant flies. In conclusion, the present study provides novel evidence that CI may be an effective drug for the treatment of T2D.

pH Effect and Chemical Mechanisms of Antioxidant Higenamine

In this article, we determine the pH effect and chemical mechanism of antioxidant higenamine by using four spectrophotometric assays: (1) 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical (PTIO•)-scavenging assay (at pH 4.5, 6.0, and 7.4); (2) Fe³⁺-reducing power assay; (3) Cu²⁺-reducing power assay; and (4) 1,1-diphenyl-2-picryl-hydrazyl (DPPH•)-scavenging assay. The DPPH•-scavenging reaction product is further analyzed by ultra-performance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technology. In the four spectrophotometric assays, higenamine showed good dose-response curves; however, its IC₅₀ values were always lower than those of Trolox. In UPLC-ESI-Q-TOF-MS/MS analysis, the higenamine reaction product with DPPH• displayed three chromatographic peaks (retention time = 0.969, 1.078, and 1.319 min). The first gave m/z 541.2324 and 542.2372 MS peaks; while the last two generated two similar MS peaks (m/z 663.1580 and 664.1885), and two MS/MS peaks (m/z 195.9997 and 225.9971). In the PTIO•-scavenging assays, higenamine greatly decreased its IC₅₀ values with increasing pH. In conclusion, higenamine is a powerful antioxidant—it yields at least two types of final products (i.e., higenamine-radical adduct and higenamine-higenamine dimer). In aqueous media, higenamine may exert its antioxidant action via electron-transfer and proton-transfer pathways. However, its antioxidant action is markedly affected by pH. This is possibly because lower pH value weakens its proton-transfer pathway via ionization suppression by solution H⁺, and its electron-transfer pathway by withdrawing the inductive effect (-I) from protonated N-atom. These findings will aid the correct use of alkaloid antioxidants.

E-Configuration Improves Antioxidant and Cytoprotective Capacities of Resveratrols

The antioxidant and cytoprotective capacities of E-resveratrol and Z-resveratrol were compared using chemical and cellular assays. Chemical assays revealed that the two isomers were dose-dependently active in •O₂^--scavenging, ferric reducing antioxidant power (FRAP), Cu²⁺-reducing antioxidant capacity (CUPRAC), 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-scavenging (pH 7.4 and pH 4.5), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH•)-scavenging assays. The cellular assay indicated that the two isomers could also increase cell viabilities. However, quantitative analyses suggested that E-resveratrol exhibited stronger effects than Z-resveratrol in all chemical and cellular assays. Finally, the conformations of E-resveratrol and Z-resveratrol were analyzed. It can be concluded that both E-resveratrol and Z-resveratrol can promote redox-related pathways to exhibit antioxidant action and consequently protect bone marrow-derived mesenchymal stem cells (bmMSCs) from oxidative damage. These pathways include electron transfer (ET) and H⁺-transfer, and likely include hydrogen atom transfer (HAT). The E-configuration, however, improves antioxidant and cytoprotective capacities of resveratrols. The detrimental effect of the Z-configuration may be attributed to the non-planar preferential conformation, where two dihedral angles block the extension of the conjugative system.

2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide Radical (PTIO•) Trapping Activity and Mechanisms of 16 Phenolic Xanthones

This study used the 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) trapping model to study the antioxidant activities of 16 natural xanthones in aqueous solution, including garcinone C, γ-mangostin, subelliptenone G, mangiferin, 1,6,7-trihydroxy-xanthone, 1,2,5-trihydroxyxanthone, 1,5,6-trihydroxyxanthone, norathyriol, 1,3,5,6-tetrahydroxy-xanthone, isojacareubin, 1,3,5,8-tetrahydroxyxanthone, isomangiferin, 2-hydroxyxanthone, 7-O-methylmangiferin, neomangiferin, and lancerin. It was observed that most of the 16 xanthones could scavenge the PTIO• radical in a dose-dependent manner at pH 4.5 and 7.4. Among them, 12 xanthones of the para-di-OHs (or ortho-di-OHs) type always exhibited lower half maximal inhibitory concentration (IC₅₀) values than those not of the para-di-OHs (or ortho-di-OHs) type. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) analysis revealed that most of these xanthones gave xanthone-xanthone dimers after incubation with PTIO•, except for neomangiferin. Based on these data, we concluded that the antioxidant activity of phenolic xanthone may be mediated by electron-transfer (ET) plus H⁺-transfer mechanisms. Through these mechanisms, some xanthones can further dimerize unless they bear huge substituents with steric hindrance. Four substituent types (i.e., para-di-OHs, 5,6-di-OHs, 6,7-di-OHs, and 7,8-di-OHs) dominate the antioxidant activity of phenolic xanthones, while other substituents (including isoprenyl and 3-hydroxy-3-methylbutyl substituents) play a minor role as long as they do not break the above four types.

Antioxidant Structure⁻Activity Relationship Analysis of Five Dihydrochalcones

The study determined the comparative antioxidant capacities of five similar dihydrochalcones: phloretin, phloridzin, trilobatin, neohesperidin dihydrochalcone, and naringin dihydrochalcone. In the ferric-reducing antioxidant power (FRAP) assay, the antioxidant activities of pairs of dihydrochalcones had the following relationship: phloretin > phloridzin, phloretin > trilobatin, trilobatin > phloridzin, trilobatin > naringin dihydrochalcone, and neohesperidin dihydrochalcone > naringin dihydrochalcone. Similar relative antioxidant levels were also obtained from 1,1-diphenyl-2-picryl-hydrazl radical (DPPH•)-scavenging, 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS•⁺)-scavenging, and superoxide radical (•O₂⁻)-scavenging assays. Using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC−ESI−Q−TOF−MS/MS) analysis for the reaction products with DPPH•, phloretin, phloridzin, and trilobatin were found to yield both dihydrochalcone-DPPH adduct and dihydrochalcone-dihydrochalcone dimer, whereas naringin dihydrochalcone gave a naringin dihydrochalcone-DPPH adduct, and neohesperidin dihydrochalcone gave a dimer. In conclusion, the five dihydrochalcones may undergo redox-based reactions (especially electron transfer (ET) and hydrogen atom transfer (HAT)), as well as radical adduct formation, to exert their antioxidant action. Methoxylation at the ortho-OH enhances the ET and HAT potential possibly via p-π conjugation, whereas the glycosylation of the –OH group not only reduces the ET and HAT potential but also hinders the ability of radical adduct formation. The 2′,6′-di-OH moiety in dihydrochalcone possesses higher ET and HAT activities than the 2′,4′-di-OH moiety because of its resonance with the adjacent keto group.

Effect of Double Bond Position on 2-Phenyl-benzofuran Antioxidants: A Comparative Study of Moracin C and Iso-Moracin C

Two 2-phenyl-benzofurans, moracin C {2-[3′,5′-dihydroxy-4′-(3-methlbut-2-enyl)phenyl]-6-hydroxybenzofuran} and its isomer iso-moracin C{2-[3′,5′-dihydroxy-4′-(3-methlbut-1-enyl)phenyl]-6-hydroxybenzofuran}, were comparatively studied using redox-related antioxidant assays and non-redox antioxidant assays. Moracin C always resulted in higher IC₅₀ values than iso-moracin C in the redox-related antioxidant assays, including •O₂⁻-inhibition, Cu²⁺-reducing power, DPPH•-inhibition, and ABTS⁺•-inhibition assays. In the non-redox antioxidant assay, moracin C and iso-moracin C underwent similar radical-adduct-formation (RAF), evidenced by the peaks at m/z 704 and m/z 618 in HPLC-MS spectra. In conclusion, both moracin C and iso-moracin C can act as 2-phenyl-benzofuran antioxidants; their antioxidant mechanisms may include redox-related ET and H⁺-transfer, and non-redox RAF. A double bond at the conjugation position can enhance the redox-related antioxidant potential, but hardly affects the RAF potential.

π-π Conjugation Enhances Oligostilbene's Antioxidant Capacity: Evidence from α-Viniferin and Caraphenol A

α-Viniferin and caraphenol A, the two oligostilbenes, have the sole difference of the presence or absence of an exocyclic double bond at the π-π conjugative site. In this study, the antioxidant capacity and relevant mechanisms for α-viniferin and caraphenol A were comparatively explored using spectrophotometry, UV-visible spectral analysis, and electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC–ESI–Q–TOF–MS/MS) analysis. The spectrophotometric results suggested that caraphenol A always gave lower IC₅₀ values than α-viniferin in cupric ion-reducing antioxidant capacity assay, ferric-reducing antioxidant power assay, 1,1-diphenyl-2-picryl-hydrazl radical (DPPH•)-scavenging, and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical-scavenging assays. In UV-visible spectra analysis, caraphenol A was observed to show enhanced peaks at 250–350 nm when mixed with Fe²⁺, but α-viniferin exhibited no similar effects. UPLC–ESI–Q–TOF–MS/MS analysis revealed that α-viniferin mixed with DPPH• produced radical adduct formation (RAF) peak (m/z = 1070–1072). We conclude that the antioxidant action of α-viniferin and caraphenol A may involve both redox-mediated mechanisms (especially electron transfer and H⁺-transfer) and non-redox-mediated mechanisms (including Fe²⁺-chelating or RAF). The π-π conjugation of the exocyclic double bond in caraphenol A can greatly enhance the redox-mediated antioxidant mechanisms and partially promote the Fe²⁺-chelating mechanism. This makes caraphenol A far superior to α-viniferin in total antioxidant levels.

Antioxidation and Cytoprotection of Acteoside and Its Derivatives: Comparison and Mechanistic Chemistry

The study tried to explore the role of sugar-residues and mechanisms of phenolic phenylpropanoid antioxidants. Acteoside, along with its apioside forsythoside B and rhamnoside poliumoside, were comparatively investigated using various antioxidant assays. In three electron-transfer (ET)-based assays (FRAP, CUPRAC, PTIO•-scavenging at pH 4.5), the relative antioxidant levels roughly ruled as: acteoside >forsythoside B > poliumoside. Such order was also observed in H⁺-transfer-involved PTIO•-scavenging assay at pH 7.4, and in three multiple-pathway-involved radical-scavenging assays, i.e., ABTS⁺•-scavenging, DPPH•-scavenging, and •O₂^--scavenging. In UV-vis spectra, each of them displayed a red-shift at 335→364 nm and two weak peaks (480 and 719 nm), when mixed with Fe²⁺; however, acteoside gave the weakest absorption. In Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) analysis, no radical-adduct-formation (RAF) peak was found. MTT assay revealed that poliumoside exhibited the highest viability of oxidative-stressed bone marrow-derived mesenchymal stem cells. In conclusion, acteoside, forsythoside B, and poliumoside may be involved in multiple-pathways to exert the antioxidant action, including ET, H⁺-transfer, or Fe²⁺-chelating, but not RAF. The ET and H⁺-transfer may be hindered by rhamnosyl and apiosyl moieties; however, the Fe²⁺-chelating potential can be enhanced by two sugar-residues (especially rhamnosyl moiety). The general effect of rhamnosyl and apiosyl moieties is to improve the antioxidant or cytoprotective effects.

The Study of Anti-/Pro-Oxidant, Lipophilic, Microbial and Spectroscopic Properties of New Alkali Metal Salts of 5-O-Caffeoylquinic Acid

Lithium, sodium, potassium, rubidium and caesium salts of 5-O-caffeoylquinic acid (chlorogenic acid, 5-CQA) were synthesized and described by FT-IR (infrared spectroscopy), FT-Raman (Raman spectroscopy), UV (UV absorption spectroscopy), ¹H (400.15 MHz), ¹³C (100.63 MHz) NMR (nuclear magnetic resonance spectroscopy). The quantum-chemical calculations at the B3LYP/6-311++G** level were done in order to obtain the optimal structures, IR spectra, NBO (natural bond orbital) atomic charges, HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) orbitals and chemical reactivity parameters for 5-CQA and Li, Na and K 5-CQAs (chlorogenates). The DPPH (α, α-diphenyl-β-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays were used for the preliminary estimation of the antioxidant properties of alkali metal chlorogenates and chlorogenic acid. In the DPPH assay the EC₅₀ parameter were equal to 7.39 μM for 5-CQA and was in the range of 4.50-5.89 μM for salts. The FRAP values for two different concentrations (5 and 2.5 μM) of the studied compounds were respectively 114.22 and 72.53 μM Fe²⁺ for 5-CQA, whereas for salts they were 106.92-141.13 and 78.93-132.00 μM Fe²⁺. The 5-CQA and its alkali metal salts possess higher antioxidant properties than commonly applied antioxidants (BHA, BHT, l-ascorbic acid). The pro-oxidant action of these compounds on trolox oxidation was studied in the range of their concentration 0.05-0.35 μM. The lipophilicity (logk_w) of chlorogenates and chlorogenic acid was determined by RP-HPLC (reverse phase-high performance liquid chromatography) using five different columns (C8, PHE (phenyl), CN (cyano), C18, IAM (immobilized artificial membrane)). The compounds were screened for their in vitro antibacterial activity against E. coli, Bacillus sp., Staphylococcus sp., Streptococcus pyogenes and antifungal activity against Candida sp. The 5-CQA possessed lower antibacterial (minimal inhibitory concentration, MIC = 7.06 mM) and antifungal (MIC = 14.11 mM) properties than its alkali metal salts (MIC values: 6.46-2.63 mM and 12.91-5.27mM, respectively). The synthesized chlorogenates possessed better antioxidant, lipophilic, antimicrobial as well as lower pro-oxidant properties than the ligand alone. Moreover, a systematic change of the activity of alkali metal salts along the series Li→Cs suggests that there are correlations between the studied biological properties. The type of metal cation in the carboxylate group of chlorogenate is crucial for the activity of studied compounds.

Antioxidant and Cytoprotective Effects of Tibetan Tea and Its Phenolic Components

Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea (LATT) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic acid, and four catechins (i.e., (+)-catechin, (−)-catechin gallate (CG), (−)-epicatechin gallate (ECG), and (−)-epigallocatechin gallate). Gallic acid, the four catechins, and LATT were then comparatively investigated by four antioxidant assays: ferric reducing antioxidant power, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) scavenging, 1,1-diphenyl-2-picryl-hydrazl radical scavenging, and 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical scavenging assays. In these assays, LATT, along with the five phenolic components, increased their antioxidant effects in a concentration-dependent manner; however, the half maximal scavenging concentrations of ECG were always lower than those of CG. Gallic acid and the four catechins were also suggested to chelate Fe²⁺ based on UV-visible spectral analysis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC−ESI−Q−TOF−MS/MS) analysis suggested that, when mixed with PTIO•, the five phenolic components could yield two types of radical adduct formation (RAF) products (i.e., tea phenolic dimers and tea phenolic-PTIO• adducts). In a flow cytometry assay, (+)-catechin and LATT was observed to have a cytoprotective effect towards oxidative-stressed bone marrow-derived mesenchymal stem cells. Based on this evidence, we concluded that LATT possesses antioxidative or cytoprotective properties. These effects may mainly be attributed to the presence of phenolic components, including gallic acid and the four catechins. These phenolic components may undergo electron transfer, H⁺-transfer, and Fe²⁺-chelating pathways to exhibit antioxidative or cytoprotective effects. In these effects, two diastereoisomeric CG and ECG showed differences to which a steric effect from the 2-carbon may contribute. Phenolic component decay may cause RAF in the antioxidant process.

Antioxidant and Cytoprotective Effects of the Di-O-Caffeoylquinic Acid Family: The Mechanism, Structure-Activity Relationship, and Conformational Effect

In this study, a series of di-O-caffeoylquinic acids (di-COQs) were systematically investigated for their antioxidant and cytoprotective effects towards •OH-damaged bone marrow-derived mesenchymal stem cells (bmMSCs). Five di-COQs were measured using a set of antioxidant assays. The results show that adjacent 4,5-Di-O-caffeoylquinic acid (4,5-COQ) and 3,4-di-O-caffeoylquinic acid (3,4-COQ) always gave lower IC₅₀ values than did non-adjacent di-COQs. In the Fe²⁺-chelating assay, 4,5-COQ and 3,4-COQ presented greater UV-Vis spectra and darker colors than did non-adjacent di-COQs. In the UPLC-ESI-MS/MS analysis, no corresponding radical adduct formation (RAF) peak was found in the reaction products of di-COQs with PTIO•. In the MTT assay, all di-COQs (especially 1,5-COQ, 1,3-COQ, and 4,5-COQ) dose-dependently increased the cellular viabilities of •OH-damaged bmMSCs. Based on this evidence, we conclude that the five antioxidant di-COQs can protect bmMSCs from •OH-induced damage. Their antioxidant mechanisms may include electron-transfer (ET), H⁺-transfer, and Fe²⁺-chelating, except for RAF. Two adjacent di-COQs (4,5-COQ and 3,4-COQ) always possessed a higher antioxidant ability than the non-adjacent di-COQs (1,3-COQ, 1,5-COQ, and 3,5-COQ) in chemical models. However, non-adjacent 1,3-COQ and 1,5-COQ exhibited a higher cytoprotective effect than did adjacent di-COQs. These differences can be attributed to the relative positions of two caffeoyl moieties and, ultimately, to the conformational effect from the cyclohexane skeleton.

Protective Mechanism of the Antioxidant Baicalein toward Hydroxyl Radical-Treated Bone Marrow-Derived Mesenchymal Stem Cells

Our study explores the antioxidant and cytoprotective effects of baicalein and further discusses the possible mechanisms. A methyl thiazolyl tetrazolium (MTT) assay revealed that baicalein could considerably enhance the viability of hydroxyl radical-treated bone marrow-mesenchymal stem cells (bmMSCs) at 37-370 µM. The highest viability rate was 120.4%. In subsequent studies, baicalein was observed to effectively scavenge hydroxyl radical and PTIO• radicals, reducing Fe³⁺ and Cu²⁺ ions. In the Fe²⁺-chelating UV-vis spectra, mixing of baicalein with Fe²⁺ yielded two evident redshifts (275 → 279 nm and 324 → 352 nm) and a broad absorption peak (λ_max ≈ 650 nm, ε = 1.6 × 10³ L mol^-1·cm^-1). Finally, we compared the Fe²⁺-chelating UV-vis spectra of baicalein and its analogues, including 5-hydroxyflavone, 6-hydroxyflavone, 7-hydroxyflavone, catechol, pyrogallol, and chrysin. This analysis revealed that the 4-keto group of the C-ring played a role. The 5,6,7-trihydroxy-group (pyrogallol group) in the A-ring served as an auxochrome, enhancing the absorbance of the UV-vis spectra and deepening the color of the Fe²⁺-complex. We concluded that baicalein, as an effective hydroxyl radical-scavenger, can protect bmMSCs from hydroxyl radical-mediated oxidative stress. Its hydroxyl radical-scavenging effects are likely exerted via two pathways: direct scavenging of hydroxyl radicals, possibly through electron transfer, and indirect inhibition of hydroxyl radical generation via Fe²⁺ chelation through the 4-keto-5,6,7-trihydroxy groups.

The mechanism of (+) taxifolin's protective antioxidant effect for •OH-treated bone marrow-derived mesenchymal stem cells

The natural dihydroflavonol (+) taxifolin was investigated for its protective effect on Fenton reagent-treated bone marrow-derived mesenchymal stem cells (bmMSCs). Various antioxidant assays were used to determine the possible mechanism. These included •OH-scavenging, 2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide radical-scavenging (PTIO•-scavenging), 1, 1-diphenyl-2-picryl-hydrazl radical-scavenging (DPPH•-scavenging), 2, 2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) radical-scavenging (ABTS⁺•-scavenging), Fe³⁺-reducing, and Cu²⁺-reducing assays. The Fe²⁺-binding reaction was also investigated using UV-Vis spectra. The results revealed that cell viability was fully restored, even increasing to 142.9 ± 9.3% after treatment with (+) taxifolin. In the antioxidant assays, (+) taxifolin was observed to efficiently scavenge •OH, DPPH• and ABTS⁺• radicals, and to increase the relative Cu²⁺- and Fe³⁺-reducing levels. In the PTIO•-scavenging assay, its IC₅₀ values varied with pH. In the Fe²⁺-binding reaction, (+) taxifolin was found to yield a green solution with two UV-Vis absorbance peaks: λ_max = 433 nm (ε =5.2 × 10² L mol⁻¹ cm ⁻¹) and λ_max = 721 nm (ε = 5.1 × 10² L mol⁻¹ cm ⁻¹). These results indicate that (+) taxifolin can act as an effective •OH-scavenger, protecting bmMSCs from •OH-induced damage. Its •OH-scavenging action consists of direct and indirect antioxidant effects. Direct antioxidation occurs via multiple pathways, including ET, PCET or HAT. Indirect antioxidation involves binding to Fe²⁺.