Plant Phenolics Extraction from Flos Chrysanthemi: Response Surface Methodology Based Optimization and the Correlation Between Extracts and Free Radical Scavenging Activity

Design, synthesis, and anti-oomycete activity of 3-acyloxymaltol/ethyl maltol derivatives

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site.

Effect of Extraction Methods on Chemical Characteristics and Bioactivity of Chrysanthemum morifolium cv. Fubaiju Extracts

Chrysanthemum morifolium cv. Fubaiju (CMF) is regarded as one of the three most renowned varieties of white Chrysanthemum in China, and different extraction methods have significant effects on its composition and activities. Therefore, six extractions were used in this study to assess the effects on extracts. The basic chemical composition showed that hot water extract (Hw) had the highest total phenolic content, alkali water immersion-assisted hot water extract (Al) had the highest content of protein, and enzyme-assisted hot water extract (Enz) had the highest content of carbohydrate. The UPLC-Q-Exactive-MS results evinced the presence of 19 small-molecule compounds, including chlorogenic acid, caffeic acid, tuberonic acid glucoside, luteolin-7-O-rutinoside, and other substances. In addition, the antioxidant test found that the Hw exhibited the best 1,1-diphenyl-2-picrylhydrazyl (DPPH) (82.05 ± 1.59 mM TE/mg) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (61.91 ± 0.27 mM TE/mg) scavenging ability. The anti-glycation test demonstrated that Enz possessed the most pronounced inhibitory effect on glycation products, including fructosamine and advanced glycation end products (AGEs). Additionally, the Enz also exhibited the most significant inhibitory effect on the protein oxidation product N'-formylkynurenine. The correlation analysis revealed that there was a close relationship between antioxidant properties and glycation resistance of extracts, and tuberonic acid glucoside, 1,3-di-O-caffeoylquinic acid, 1,4-Dicaffeoylquinic acid, quercetin-7-O-β-D-glucopyranoside, and isochlorogenic acid B were key small molecule components that affected activities. In summary, the extracts of CMF can be regarded as an excellent antioxidant and anti-glycosylation agent.

Influence of Five Drying Methods on Active Compound Contents and Bioactivities of Fresh Flowers from Syringa pubescens Turcz

The flower of Syringa pubescens Turcz. is used in Chinese folk medicine and also as a flower tea for healthcare. The effects of five drying methods on the active compound contents, the antioxidant abilities, anti-inflammatory properties and enzyme inhibitory activities were evaluated. The plant materials were treated using shade-drying, microwave-drying, sun-drying, infrared-drying and oven-drying. The seven active compounds were simultaneously determined using an HPLC method. Furthermore, the chemical profile was assessed using scanning electron microscopy, ultraviolet spectroscopy and infrared spectroscopy. The antioxidant capacities and protective effects on L02 cells induced with hydrogen peroxide were measured. The anti-inflammatory effects on lipopolysaccharide-induced RAW264.7 cells were investigated. The enzyme inhibitory activities were determined against α-amylase, α-glucosidase cholinesterases and tyrosinase. The results indicated that drying methods had significant influences on the active compound contents and biological properties. Compared with other samples, the OD samples possessed low IC50 values with 0.118 ± 0.004 mg/mL for DPPH radical, 1.538 ± 0.0972 for hydroxyl radical and 0.886 ± 0.199 mg/mL for superoxide radical, while the SHD samples had stronger reducing power compared with other samples. The SHD samples could be effective against H2O2-induced injury on L02 cells by the promoting of T-AOC, GSH-PX, SOD and CAT activities and the reducing of MDA content compared with other samples. Furthermore, SPF samples, especially the SHD sample, could evidently ameliorate inflammation through the inhibition of IL-6, IL-1β and TNF-α expression. All the studied SPF samples exhibited evidently inhibitory effects on the four enzymes. The IC50 values of inhibitory activity on α-glucosidase and α-amylase from SHD sample were 2.516 ± 0.024 and 0.734 ± 0.034 mg/mL, respectively. SD samples had potential inhibitory effects on cholinesterases and tyrosinase with IC50 values of 3.443 ± 0.060 and 1.732 ± 0.058 mg/mL. In consideration of active compound contents and biological activities, it was recommended that SHD and SD be applied for drying SPF at an industrial scale.

Separation and Purification of Taxanes from Crude Taxus cuspidata Extract by Antisolvent Recrystallization Method

Taxanes are natural compounds with strong antitumor activity. In this study, we first enriched taxanes by ultrasonic extraction and liquid–liquid extraction from Taxus cuspidata, then purified these taxanes by the antisolvent recrystallization method, and discussed the effects of four recrystallization conditions on the purity of eight target compounds. The most promising purification results were obtained using methanol as a solvent and water as an antisolvent. Response surface methodology (RSM) was used to further optimize the optimal purification conditions: when the crude extraction concentration was 555.28 mg/mL, an antisolvent to solvent volume ratio was 28.16 times, the deposition temperature was 22.91 °C, and the deposition time was 1.76 min, the purity of the taxanes reached its maximum. The scanning electron microscopy (SEM) results showed that recrystallization could effectively reduce the particle size of crude Taxus cuspidata and control the particle morphology. X-ray diffraction (XRD) and Raman spectrum experiments demonstrated that the amorphous state of the crude Taxus cuspidata did not change during the recrystallization process, and always remained amorphous. This recrystallization method can effectively improve the purity of taxanes in Taxus cuspidata, and is suitable for the preliminary purification of taxanes.

Rapid Screening of 352 Pesticide Residues in Chrysanthemum Flower by Gas Chromatography Coupled to Quadrupole-Orbitrap Mass Spectrometry with Sin-QuEChERS Nanocolumn Extraction

To analyze pesticide residues, GC coupled with quadrupole-Orbitrap MS (GC-Orbitrap-MS) has become a powerful tool because of its unique characteristics of accurate mass full-spectrum acquisition, high resolution, fast acquisition rates, and overcoming matrix interference. This paper presents an efficiency evaluation of GC-Orbitrap-MS for identification and quantitation in the 352 pesticide residues analysis of chrysanthemum flowers in full-scan mode. A streamlined pretreatment approach using one-step extraction and dilution was used, which provided high-throughput processing and excellent recovery. The samples were extracted using acetonitrile. The extracted solution was purified by a Sin-QuEChERS Nano column to suppress the matrix in chrysanthemum flowers and determined by GC-Orbitrap-MS. The calibration curves for the 352 pesticides obtained by GC-Orbitrap-MS were linear in the range of 0.5-200 μg·kg^-1, with the correlation coefficients higher than 0.99. The limits of detection (LODs) and the limits of quantification (LOQs) for the 352 pesticide residues were 0.3-3.0 μg·kg^-1 and 1.0-10.0 μg·kg^-1, respectively. The average recoveries in chrysanthemum flower at three levels were 95.2%, 88.6%, and 95.7%, respectively, with relative standard deviations (RSDs) of 7.1%, 7.5%, and 7.2%, respectively. Lastly, the validated method and retrospective analysis was applied to a total of 200 chrysanthemum flower samples bought in local pharmacies. The proposed method can simultaneously detect multipesticide residues with a good performance in qualitative and quantitative detection.

Synthesis and Anti-Oomycete Preliminary Mechanism of Sulfonate Derivatives of Ethyl Maltol

To discover novel molecules with unique mechanism against plant pathogenic oomycetes, sixteen new sulfonate derivatives of ethyl maltol (3a-p) were synthesized by structural modification of 2-ethyl-3-hydroxy-4H-pyran-4-one, and their anti-oomycete activity against a serious agricultural disease, Phytophthora capsici Leonian was determined in this study. Among all tested compounds, derivatives 3e, 3m and 3p exhibited the most potent anti-oomycete activity against P. capsici with EC₅₀ values of 19.40, 21.04 and 31.10 mg/L, respectively; especially 3e and 3m showed the best promising and pronounced anti-oomycete activity than zoxamide (EC₅₀ =26.87 mg/L). The results further proved that 4-tert-butylphenylsulfonyl group, 3-nitro-4-chlorophenylsulfonyl group and 8-quinolinesulfonyl group introduced at the hydroxy position of ethyl maltol or maltol were necessary for obtaining the most potent compounds. Further mechanism studies of P. capsici treated with 3e demonstrated that this compound can affect the growth of mycelia by disrupting the integrity of the membrane, and the higher the concentration of the compound is, the greater the degree of membrane integrity damage. These important results will pave the way for further modification of ethyl maltol to develop potential new fungicides.

Characterization of the physicochemical properties, antioxidant activity, and antiproliferative activity of natural melanin from S. reiliana

This study aimed to characterize the physicochemical properties and stability of L-25 melanin extracted from Sporisorium reilianum (S. reiliana). The results showed that the maximum absorption wavelength of melanin was 215 nm. Reducing agents, heat, light, microwaving, oxidants, and common food additives did not affect the melanin. Additionally, it has a good metal stability except Mn²⁺. The IR spectra revealed the presence of O–H, N–H, C=O, and C=C bonds as well as carboxyl, alcohol hydroxyl, and phenolic hydroxyl groups and a pyran ring. L-25 melanin could be defined as DL-hydroxy phenylalanine (DOPA)-melanin. The antioxidant and antiproliferative were also measured. The melanin has a specific stability and high antioxidant activity, including a strong DPPH free radical scavenging ability, and protected damaged HepG2 cells by reducing reactive oxygen species, malondialdehyde, and lactate dehydrogenase content. In conclusion, S. reilianum represents a novel source of melanin, that could be applied to health food or food additives. Our results show that melanin from S. reilianum is a natural pigment with good stability that has a great prospect of development and application, providing a theoretical basis and methods for its further processing and development as a functional food.

Response surface methodology optimised solvothermal system enables an efficient extraction of echinacoside and oleuropein from Syringa pubescens Turcz

INTRODUCTION

Syringa pubescens Turcz. was reported to be abundant in the Funiu Mountains of Henan Province and can be used to treat hepatitis and cirrhosis. In order to develop and utilise the resource, a fast and simple technique to extract bioactive compounds is needed.

OBJECTIVES

Our aims were to provide an extraction technique of glycosides from S. pubescens and study the antioxidant activity of this material.

METHODS

Box-Behnken design (BBD) was employed with three factors at three levels. The process parameters such as ethanol concentration (X₁ ), temperature (X₂ ), and solvent-solid ratio (X₃ ) could significantly influence efficiency and yield of target compounds. High-performance liquid chromatography (HPLC) was used to determine the content of glycosides. DPPH (α,α-diphenyl-β-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and reducing power were used to evaluate the antioxidant activity of S. pubescens extract.

RESULTS

The optimal parameters for the maximal extraction yield were obtained with ethanol concentration of 68%, temperature of 89°C, solvent-solid ratio of 46 mL/g, and time of 20 min. The S. pubescens extract showed strong antioxidant properties in vitro.

CONCLUSION

The findings indicated the potential application of solvothermal extraction method to extract bioactive compounds from S. pubescens Turcz. Furthermore, the S. pubescens extract could be used as an important resource of antioxidant activity.

Traditional Chinese herbal medicine-potential therapeutic application for the treatment of COVID-19

Traditional Chinese Medicine (TCM) is a complete medical system that has evolved over millennia to include practices and procedures such as acupuncture, herbal medicine, manual therapies, nutrition, and mind-body therapies such as qi gong. In modern-day China and other Asian countries, TCM is a medical subspecialty utilized alongside western biomedicine. During the current Coronavirus Disease 19 (COVID-19) pandemic, TCM and TCM herbal medicine is being used and a number of single herbs and combination formulas have significant bioactivity and therapeutic potential. The purpose of this paper is to highlight the use of TCM in the treatment of COVID-19. This commentary provides the reader with a concise background on COVID-19 and summarizes TCM concepts including identification, pattern diagnosis, and treatment principles commonly used for the treatment of viral influenza-like diseases. It also highlights some of the challenges and potential for using TCM in an integrated medical setting.

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.

Synthesis of sulfonate derivatives of maltol and their biological activity against Phytophthora capsici and Bursaphelenchus xylophilus in vitro

Sixteen sulfonate derivatives of maltol were synthesized and screened in vitro for their anti-oomycete and nematicidal activity against Phytophthora capsici and Bursaphelenchus xylophilus, respectively. Among all the compounds, 3e, 3m, and 3p exhibited the most promising and pronounced anti-oomycete activity against P. capsici than zoxamide, and the EC₅₀ values of 25.42, 18.44, 23.69, and 27.99 mg/L, respectively; compounds 3e, 3m, 3n, and 3p exhibited potent nematicidal activity with LC₅₀ values ranging from 1 to 2 mg/L, especially 3m and 3n showed the best promising and pronounced nematicidal activity, with LC₅₀ values of 1.1762 and 1.2384 mg/L, respectively. [Formula: see text].

Sorbus umbellata (Desf.) Fritsch var. umbellata Leaves: Optimization of Extraction Conditions and Investigation Antimicrobial, Cytotoxic, and β-Glucuronidase Inhibitory Potential

This study aimed to optimize the extraction conditions for Sorbus umbellata (Desf.) Fritsch var. umbellata leaves to maximize the phenolic content and their antioxidant activity and to investigate β-glucuronidase (GUS) enzyme inhibitory, antimicrobial and cytotoxic potentials of the extracts obtained under optimum conditions. The optimum extraction conditions were found to be 78.2 and 79.7% solvent, 73.1 and 71.5 °C, and 89.9 and 88.8 min to maximize phenolic content and antioxidant activity, respectively. Low values of coefficient of variations indicate the high reliability and reproducibility of the conducted extraction experiments. Bioactivity results showed that extracts had cytotoxic effect on the MCF-7 and A549 cells where the highest cell proliferation inhibition was observed for the A549 cell line (71.8% at 150 μg/mL). Staphylococcus aureus showed highest zone of inhibition (19.3 mm) in all bacteria followed by Escherichia coli. Additionally, extracts displayed potential GUS inhibitory activity. In conclusion, Sorbus umbellata leaf extract can be obtained by optimized cost-saving extraction and has a potential bioactivity to be utilized as a food ingredient for high value-added products and/or nutraceuticals development where it can combat oxidative stress and GUS mediated reactive metabolite formation.