Phenolic composition, antioxidant, cytotoxic activities and cardioprotective effect of hydroalcoholic extract from aerial-parts of Hypericum attenuatum Fisch. ex Choisy

This study investigated phenolic metabolites, antioxidant, cytotoxic and cardioprotective effects of the hydroalcoholic extract from the aerial parts of Hypericum attenuatum Fisch. ex Choisy. The total phenolic and flavonoid contents of the extract were 132.40 ± 2.06 mg GAE/g and 101.46 ± 1.47 mg QE/g respectively. The extract exhibited antioxidant activities with an EC50 value against DPPH radical of 0.099 ± 0.03 mg/mL and a FRAP value of 1.22 ± 0.086 mmol/L Fe2+. The extract could protect H9c2 cardiomyoblasts from the injury of H2O2, while it restored the H9c2 cell viability to 82.69 ± 2.33% at 100 μg/mL. The extract possessed cytotoxicity on MGC803, C666-1 and SW620 cells with IC50 values of 69.77 ± 2.43 μg/mL, 74.97 ± 1.08 μg/mL and 58.91 ± 1.81 μg/mL, respectively. Moreover, it could promote apoptosis of the tested cancer cells. This research provided useful information for the utilization of H. attenuatum as herbal medicine.

Comprehensive Analysis of Phenolic Constituents, Biological Activities, and Derived Aroma Differences of Penthorum chinense Pursh Leaves after Processing into Green and Black Tea

Penthorum chinense Pursh (Penthoraceae) is a traditional herb used in Miao medical systems that is also processed into foods (e.g., tea products) in China. Different processing methods significantly affect the volatile compounds, phenolic constituents, and biological activities. This study aimed to produce P. chinense green tea leaves (GTL), black tea leaves (BTL), and untreated leaves (UL) to investigate differences in their flavor substances, functional components, antioxidant activity, alcohol dehydrogenase (ADH) activity, and acetaldehyde dehydrogenase (ALDH) activity. The results showed that 63, 56, and 56 volatile compounds were detected in UL, GTL, and BTL, respectively, of which 43 volatile compounds were identified as differential metabolites among them. The total phenolic content (97.13-179.34 mg GAE/g DW), flavonoid content (40.07-71.93 mg RE/g DW), and proanthocyanidin content (54.13-65.91 mg CE/g DW) exhibited similar trends, decreasing in the order of UL > BTL > GTL. Fourteen phenolic compounds were determined, of which gallic acid, (-)-epicatechin, and pinocembrin 7-O-glucoside showed a sharp decrease in content from UL to BTL, while the content of pinocembrin 7-O-(3″-O-galloy-4″, 6″-hexahydroxydiphenoyl)-glucoside and pinocembrin significantly increased. GTL showed better DPPH/ABTS·+ scavenging ability and ferric-reducing ability than UL. The ADH and ALDH activities decreased in the order of GTL > UL > BTL. Therefore, tea products made with P. chinense leaves contained an abundance of functional compounds and showed satisfactory antioxidant and hepatoprotective activities, which are recommended for daily consumption.

Exploring for HPLC-MS/MS Profiles and Biological Activities of Different Extracts from Allium lycaonicum Siehe ex Hayek from Turkey Flora

The present study was designed to determine the phenolic constituents, antioxidant, and enzyme inhibition activities of aerial parts and bulbs of Allium lycaonicum (family Amaryllidaceae). Extracts were prepared by maceration and Soxhlet/infusion using hexane, methanol, and water as extraction solvents. Generally, extracts from the aerial parts showed higher total phenolic and individual components and antioxidant activity than their respective bulb extracts. Maceration with water was the best to extract total phenolic content from the aerial parts (29.00 mg gallic acid equivalents (GAE)/g), while the Soxhlet extraction with hexane (22.29 mg GAE/g) was the best for the bulb. Maceration with methanol recovered the highest total flavonoid content from both the aerial parts (41.95 mg (rutin equivalents (RE)/g) and bulb (1.83 mg RE/g). Polar extracts of aerial parts were characterized by higher abundance of kaempferol-3-glucoside (≤20,624.27 µg/mg), hyperoside (≤19,722.76 µg/g), isoquercitrin (≤17,270.70 µg/g), delphindin-3,5-diglucoside (≤14,625.21 µg/g), and rutin (≤10,901.61 µg/g) than the bulb. Aerial parts' aqueous extract, prepared by maceration, exerted the highest anti-ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical activity (64.09 mg trolox equivalents (TE)/g), Cu++ (83.03 mg TE/g) and Fe+++ (63.03 mg TE/g) reducing capacity while that prepared by infusion recorded the highest anti-DPPH (2,2-diphenyl-1-picrylhydrazyl) radical (31.70 mg TE/g) and metal chelating (27.66 mg EDTAE/g) activities. The highest total antioxidant activity (1.46 mmol TE/g) was obtained by maceration of the bulb with water. Extracts obtained by organic solvents showed remarkable enzyme inhibition properties against the tested enzymes. Soxhlet extraction of the bulb with hexane and methanol recorded the highest acetylcholinesterase inhibition (4.75 mg galanthamine equivalents (GALAE)/g) and tyrosinase inhibition (139.95 mg kojic acid equivalents/g) activities, respectively. Extracts obtained by maceration of the bulb with methanol and the aerial parts with hexane exerted the highest glucosidase inhibition (3.25 mmol acarbose equivalents/g) and butyrylcholinesterase inhibition (20.99 mg GALAE/g) activities, respectively. These data indicated that A. lycaonicum is a source of bioactive molecules with potential antioxidant and enzyme inhibition properties. Nonetheless, the extracts obtained through various solvents and extraction techniques showed variations in their phytoconstituent composition and biological properties.

Potential Benefits of Black Chokeberry (Aronia melanocarpa) Fruits and Their Constituents in Improving Human Health

Aronia berry (black chokeberry) is a shrub native to North America, of which the fresh fruits are used in the food industry to produce different types of dietary products. The fruits of Aronia melanocarpa (Aronia berries) have been found to show multiple bioactivities potentially beneficial to human health, including antidiabetic, anti-infective, antineoplastic, antiobesity, and antioxidant activities, as well as heart-, liver-, and neuroprotective effects. Thus far, phenolic compounds, such as anthocyanins, cyanidins, phenolic acids, proanthocyanidins, triterpenoids, and their analogues have been identified as the major active components of Aronia berries. These natural products possess potent antioxidant activity, which contributes to the majority of the other bioactivities observed for Aronia berries. The chemical components and the potential pharmaceutical or health-promoting effects of Aronia berries have been summarized previously. The present review article focuses on the molecular targets of extracts of Aronia berries and the examples of promising lead compounds isolated from these berries, including cyanidin-3-O-galactoside, chlorogenic acid, quercetin, and ursolic acid. In addition, presented herein are clinical trial investigations for Aronia berries and their major components, including cancer clinical trials for chlorogenic acid and COVID-19 trial studies for quercetin. Additionally, the possible development of Aronia berries and their secondary metabolites as potential therapeutic agents is discussed. It is hoped that this contribution will help stimulate future investigations on Aronia berries for the continual improvement of human health.

NMR, LC-MS Characterization of Rydingia michauxii Extracts, Identification of Natural Products Acting as Modulators of LDLR and PCSK9

Rydingia michauxii (Briq.) Scheen and V.A.Albert (Lamiaceae) is used in Iranian traditional medicine to treat malaria, diabetes, hyperlipidemia, rheumatism and cardiovascular diseases. NMR and LC-DAD-MSⁿ analyses were used to establish extract composition and phenylethanoid, flavonoid glycosides, lignans, labdane diterpenes and iridoids were identified and quantified. The main constituents were isolated, and structures were elucidated based on NMR, polarimetric and MS measurements. A new natural compound, ent-labda-8(17),13-dien-18-glucopyranosyl ester-15,16-olide is described here. The effects of ent-labda-8(17),13-dien-18-oic acid-15,16-olide (1), ent-labda-8(17),13-dien-18-glucopyranosyl es-ter-15,16-olide (2), antirrhinoside (3), echinacoside (4), verbascoside (5), and apigenin 6,8-di-C-glucoside (6), on the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9), were studied in the human hepatocarcinoma cell line Huh7. Among the six constituents, (3) showed the strongest induction of the LDLR (3.7 ± 2.2 fold vs. control) and PCSK9 (3.2 ± 1.5 fold vs. control) at a concentration of 50 µM. The in vitro observations indicated a potential lipid lowering activity of (3) with a statin-like mechanism of action.

Phenolic Constituents of Chinese Quince Twigs (Chaenomeles sinensis Koehne) and Their Anti-Neuroinflammatory, Neurotrophic, and Cytotoxic Activities

Chaenomeles sinensis has been used as a food and traditional medicines. However, most of research on discovering bioactive constituents from this plant have been focused on its yellow fruit, Chinese quince, due to its wide usage. Here, we isolated and characterized three new phenolic compounds (1, 9, and 11) and 21 known compounds (2−8, 10, and 12−24) from the twigs of C. sinensis. Their chemical structures were established by spectroscopic and spectrometric data analysis including 1D and 2D NMR, high-resolution mass spectrometry (HRMS), electronic circular dichroism (ECD), and LC-MS analysis. Some of the isolated compounds (1−24) showed anti-neuroinflammatory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, neurotrophic activity in C6 cells through the secretion of nerve growth factor (NGF) and/or cytotoxicity against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, MKN-1).

Phenolic constituents and inhibitory effects of the leaf of Rauvolfia vomitoria Afzel on free radicals, cholinergic and monoaminergic enzymes in rat's brain in vitro

OBJECTIVES

Rauvolfia vomitoria is a medicinal plant used traditionally in Africa in the management of several human diseases including psychosis. However, there is inadequate scientific information on the potency of the phenolic constituents of R. vomitoria leaf in the management of neurodegeneration. Therefore, this study characterized the phenolic constituents and investigated the effects of aqueous and methanolic extracts of R. vomitoria leaf on free radicals, Fe²⁺-induced lipid peroxidation, and critical enzymes linked to neurodegeneration in rat's brain in vitro.

METHODS

The polyphenols were evaluated by characterizing phenolic constituents using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). The antioxidant properties were assessed through the extracts ability to reduce Fe³⁺ to Fe²⁺; inhibit ABTS, DPPH, and OH radicals and Fe²⁺-induced lipid peroxidation. The effects of the extracts on AChE and MAO were also evaluated.

RESULTS

The phenolic characterization of R. vomitoria leaf revealed that there were more flavonoids present. Both aqueous and methanolic extracts of R. vomitoria leaf had inhibitory effects with the methanolic extract having higher significant (p≤0.05) free radicals scavenging ability coupled with inhibition of monoamine oxidases. However, there was no significant (p≤0.05) difference obtained in the inhibition of lipid peroxidation and cholinesterases.

CONCLUSION

This study suggests that the rich phenolic constituents of R. vomitoria leaf might contribute to the observed antioxidative and neuroprotective effects. The methanolic extract was more potent than the aqueous extract; therefore, extraction of R. vomitoria leaf with methanol could offer better health-promoting effects in neurodegenerative condition.

Comparative study of the phenolic profile, antioxidant properties, and inhibitory effects of Moringa (Moringa oleifera Lam.) and Almond (Terminalia catappa Linn.) leaves on acetylcholinesterase and monoamine oxidase activities in the head region of Fruitfly (Drosophila melanogaster Meigen) in vitro

Moringa and Almond are medicinal plants used traditionally as food and medicine to prevent and/or treat a wide array of metabolic and neurodegenerative diseases, however, Almond leaf is underutilized. Therefore, this study investigated and compared the polyphenol constituents, antioxidant capacities, and neurochemical indices of the aqueous extracts of Moringa and Almond leaves in fruitfly head tissue homogenate in vitro. The polyphenols were evaluated by characterization using HPLC-DAD, antioxidant properties were assessed through extracts ability to inhibit ABTS, DPPH, OH, and NO radicals, reduce Fe³⁺ and MDA, and chelate Fe²⁺ . The neurochemical indices were evaluated through AChE and MAO inhibitory activities. Almond leaf had significant (p < .05) higher polyphenols and antioxidant properties. However, Moringa leaf had significant (p < .05) higher AChE inhibition and no significant (p < .05) difference was obtained in MAO inhibitory activities. Thus, Almond leaf might be more effective in managing diseases related with oxidative stress and neurodegeneration. PRACTICAL APPLICATIONS: This present study has shown that Almond leaf might offer better health promotion due to its higher phenolic constituents and antioxidant activities when compared with Moringa leaf, however, both Moringa and Almond leaves could be taken as functional foods to alleviate the symptoms of oxidative stress and neurodegenerative diseases.

Phenolic constituents from the fresh pericarps of Juglans sigillata

Three new phenolic compounds, 2,3,4-trihydroxy-1-(4'-hydroxybenzyl)benzoic acid (1), 2,3,4-trihydroxy-1-(4'-hydroxy-3'-methoxybenzyl)benzoic acid (2), and 2-(4'-hydroxy-3'-methoxybenzyl)-3,5-dimethoxy-1,4-benzoquinone (3), were isolated from the fresh pericarps of Juglans sigillata Dode. Their structures were elucidated by integrated spectroscopic techniques. Bioactivity screening results showed that compounds 1-3 exhibited moderate neuroprotective effects against H₂O₂-induced or CoCl₂-induced cellular damage in human neuroblastoma SH-SY5Y cell line.

[Phenolic constituents from Wikstroemia chamaedaphne]

The phenolic constituents of Wikstroemia chamaedaphne were investigated by various column chromatographic methods including silica gel,Sephadex LH-20,ODS and preparative HPLC,and their chemical structures were identified by physico-chemical properties and spectral analyses. Thirteen phenolic compounds were isolated and elucidated,including five flavonoids: luteolin 7-O-β-D-glucopyranoside(1),luteolin 4'-O-β-D-glucopyranoside(2),kaempferol 3-O-β-D-glucopyranoside(3),chrysoeriol 4'-O-β-D-glucopyranoside(4),chrysoeriol(5); and eight lignans:(-)-secoisolariciresinol(6),acanthosessilin A(7),(-)-nortrachelogenin(8),(+)-isolariciresinol(9),sesamin(10),syringaresinol(11),(+)-epipinoresinol(12),and [3,3',4,4'-tetrahydro-6,6'-dimethoxy-3,3'-bi-2 H-benzopyran]-4,4'-diol(13). Compounds 1, 3, 5-8, 10, 11 and 13 were obtained from the plants of W. chamaedaphne for the first time,and compounds 1,5,7,10 and 13 were obtained from the Wikstroemia genus for the first time.

Effects of chlorogenic acid, epicatechin gallate, and quercetin on mucin expression and secretion in the Caco-2/HT29-MTX cell model

Mucins are a family of large glycoproteins that represent the major structural components of the mucus and are encoded by 20 different mucin genes. Mucin expression can be modulated by different stimuli. In this study, we analyzed four mucins (MUC2, MUC3, MUC13, and MUC17) in coculture of Caco-2/HT29-MTX cells to demonstrate the variation in gene expression in the presence of antioxidant compounds like chlorogenic acid, epicatechin gallate, and quercetin (apple, tea, and coffee polyphenols, respectively). coculture of Caco-2/HT29-MTX cells was treated with polyphenols, and the expression of four mucins was determined by reverse-transcriptase PCR. In addition, the secretion levels of MUC2 were established by enzyme-linked immunoassay (ELISA) analysis. The results showed that each polyphenol compound induces different expression patterns of the mucin genes. Statistically significant up-regulation of MUC17 was observed following incubation with epicatechin gallate and quercetin. ELISA results did not prove any significant differences in protein levels of MUC2 after treatment by the polyphenol compounds. The polyphenols considered in this study may influence mucin secretion and act on diverse salivary substrates to change the barrier properties of mucins for mucus secretion in different ways.

Assessment of the phenolic content, mutagenicity and genotoxicity of ethanolic extracts of stem bark and leaves from Strychnos pseudoquina A. St.-hil

Strychnos pseudoquina is a plant species whose stem bark is used as bitter tonic beverage. The phytochemical analysis, as well as quantification of phenolic constituents and antioxidant activity of ethanolic extracts from S. pseudoquina stem bark, and leaves were conducted. The extracts were tested for mutagenicity (Ames test) and DNA-damaging activity (Plasmid Cleavage test). Leaves recorded the largest amount of flavonoids. The performed high-performance liquid chromatography (HPLC) showed flavonoids such as isorhamnetin and strychnobiflavone (phytochemical markers of the investigated species) in stem barks, but not in leaves. The proanthocyanidin content and antioxidant activity were significantly higher in stem barks than in leaves. Stem bark and leaf extracts presented mutagenic activity against TA98 and TA100 strains with, and without, metabolic activation (S9). The Plasmid Cleavage test did not indicate DNA-damaging activity. Our results suggest that extracts deriving from S. pseudoquina should be used with extreme caution, mainly the stem bark extract, which is widely used in folk medicine.

[Effect of fertilization combinations of nitrogen, phosphorus, and potassium on four phenolic compounds of cultivated Rhodiola crenulata]

This study is aimed to explore the effect of nitrogen, phosphorus and potassium combined application on the active components of Rhodiola crenulata. R. crenulata was used as the research object, "3414" fertilization experiment were conducted with regular fertilization of NPK(N 60 kg·hm⁻², P₂O₅ 100 kg·hm⁻²,KCl 160 kg·hm⁻²) to study the effect of different rates of NPK fertilization on the total amount of 4 phenolic constituents of gallic acid, salidroside, tyrol and ethyl gallate through field test. The results show that the content of salidroside was higher in the treatment of N₁P₂K₁ and N₁P₂K₂, andthe total amount of four phenols was higher in the treatment of N₁P₂K₂ and N₂P₂K₂. The suitable level of nitrogen, phosphorus and potassium promoted the accumulation of the 4 kinds of phenols.The amount of fertilizer recommended by the three factor fertilizer effect equation,(N 0 kg·hm⁻²,P₂O₅ 150 kg·hm⁻²,KCl 31.71 kg·hm⁻²) obtained the highest content of salidroside, and it was 1.54%.（N 35.54 kg·hm⁻²,P₂O₅ 150 kg·hm⁻²,KCl 237.73 kg·hm⁻²）obtained the highest content of 4 kinds of phenolic compounds, and it was 1.93%. This study provides a reference for the standardization of artificial planting of endangered Tibetan medicine.

Nutshell Extracts of Xanthoceras sorbifolia: A New Potential Source of Bioactive Phenolic Compounds as a Natural Antioxidant and Immunomodulator

The nutshell of Xanthoceras sorbifolia, a waste product in the production of edible oil, is rich in health-promoting phenolic acids. However, the individual constituents, bioactivities, and mechanism of action are largely unknown. In this study, 20 phenolic compounds were characterized in nutshell extract (NE) of X. sorbifolia by gas chromatography-mass spectrometry. Four established in vitro studies showed that NE has significant antioxidant potential. Results in vivo indicated that oral administration of NE effectively ameliorated clinical disease severity of experimental autoimmune encephalomyelitis (EAE) and reduced the neuroinflammation and the central nervous system (CNS) demyelination. The underlying mechanism of NE-induced effects involved decreased penetration of pathogenic immunocyte into the CNS, a reduced production of proinflammatory cytokines and factors, and suppressed differentiation of type 1 T helper and type 17 T helper cells through the Janus kinase/signal transducer and activator of transcription pathway. Taken together, our studies showed that X. sorbifolia nutshell, considered a waste material in the food industry, is a novel source of a natural antioxidant and immunomodulator.

Two new phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity

A new biphenyl-furocoumarin, named morescoumarin A (1), and a new prenylated flavanone, named morflavanone A (2) were isolated from the root bark of Morus alba L., together with four known compounds (3-6). Their structures were determined by extensive spectroscopic analyses and comparison with literature data. The cardioprotective effects of these compounds against doxorubicin-induced cell death were evaluated by MTT method.

Phenolic constituents from Rheum nobile and their antioxidant activity

Although the rhizomes of Rheum nobile Hook. f. et Thoms (Polygonaceae) are widely used in Tibetan medicine, no previous investigations regarding the biological activities and rarely chemical constituents of this plant have been reported. As part of an ongoing search for novel bioactive agents, a phytochemical investigation of R. nobile led to the isolation of two new compounds Rheumone B (1) and piceatannol-4'-O-β-D-(6″-O-acetyl)-glucoside (2), together with 15 known compounds by gel filtration over Sephadex LH-20 and preparative HPLC. Their structures were determined by combined spectroscopic methods. Compounds 1-10 were evaluated for their ability to scavenge 2,2-diphenyl-1-picrylhydzyl (DPPH) radical and compounds 7-10 showed relatively strong scavenging abilities with IC₅₀ values from 2.76 μM to 11.80 μM. In conclusion, naphthalene glycosides, stilbene glycosides, flavanols, especially anthraquinones are main chemical constituents of this plant. The ability to scavenge DPPH radical of compound 8 was the highest among compounds 1-10.

Antifungal Potential and Antioxidant Efficacy in the Shell Extract of Cocos nucifera (L.) (Arecaceae) against Pathogenic Dermal Mycosis

Background: Coconut is a tropical fruit well known for its essential oils that have been recognized for their biological activities since ancient times. There have been no previous investigations on the essential oils from coconut shells. Method: The shell extract of Cocos nucifera (L.) was prepared by the Soxhlet method and total phenolic content (TPC) in the extract was determined by Folin-Ciocalteu (FC) assay. The antioxidant potential of the coconut shell extract was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Minimum inhibitory concentration (MIC) of the extract was determined by the strip method against clinically isolated dermal mycosis of 20 infected patients. Result: Total antioxidant activity varied from 92.32% to 94.20% and total phenolic content was found at 5.33 ± 0.02 mg/g in the coconut shell extract. The extract was found to be most effective as an antifungal against human pathogenic fungi, including A. niger, A. flavus, T. rubrum, M. canis, M. gypseum, A. fumigates, T. mentagrophyte and T. vercossum. The crude shell extract was highly effective against all dermal mycosis tested with the MIC ranging from 62 mm to 90 mm, whereas all fungal samples showed good inhibitory effect. Conclusion: The results of the present study provide a potential cure for microbial infections.

Phenolic Constituents of Medicinal Plants with Activity against Trypanosoma brucei

Neglected tropical diseases (NTDs) affect over one billion people all over the world. These diseases are classified as neglected because they impact populations in areas with poor financial conditions and hence do not attract sufficient research investment. Human African Trypanosomiasis (HAT or sleeping sickness), caused by the parasite Trypanosoma brucei, is one of the NTDs. The current therapeutic interventions for T. brucei infections often have toxic side effects or require hospitalization so that they are not available in the rural environments where HAT occurs. Furthermore, parasite resistance is increasing, so that there is an urgent need to identify novel lead compounds against this infection. Recognizing the wide structural diversity of natural products, we desired to explore and identify novel antitrypanosomal chemotypes from a collection of natural products obtained from plants. In this study, 440 pure compounds from various medicinal plants were tested against T. brucei by in a screening using whole cell in vitro assays. As the result, twenty-two phenolic compounds exhibited potent activity against cultures of T. brucei. Among them, eight compounds—4, 7, 11, 14, 15, 18, 20, and 21—showed inhibitory activity against T. brucei, with IC₅₀ values below 5 µM, ranging from 0.52 to 4.70 μM. Based on these results, we attempt to establish some general trends with respect to structure-activity relationships, which indicate that further investigation and optimization of these derivatives might enable the preparation of potentially useful compounds for treating HAT.

Phenolic constituents from the aerial parts of Glycyrrhiza inflata and their antibacterial activities

Chemical investigation on 90% ethanol extracts of the aerial parts of Glycyrrhiza inflata afforded two new phenolic constituents, 2-(3-methyl-2-butenyl)-3,5,4'-trihydroxy-bibenzyl (1) and (2S)-6-[(E)-3-hydroxymethyl-2-butenyl]-3',4',5,7-tetrahydroxy-dihydroflavanone (2) along with seven known dihydroflavanones (3-9). Compounds 1-9 were tested for their minimum inhibitory concentration (MIC) values of inhibiting Staphylococcus aureus and Staphylococcus epidermidis. Compound 1 showed moderate antibacterial activities against both S. aureus (MIC of 50.00 μg/ml) and S. epidermidis (MIC of 12.50 μg/ml). The analysis of structure-activity relationships revealed that the antibacterial activity of dihydroflavanones (2-9) was significantly affected by the position of prenyl group.

Simultaneous determination of 15 phenolic constituents of Chinese black rice wine by HPLC-MS/MS with SPE

This study established a new method for quantitative and qualitative determination of certain components in black rice wine, a traditional Chinese brewed wine. Specifically, we combined solid-phase extraction and high-performance liquid chromatography (HPLC) with triple quadrupole mass spectrometry (MS/MS) to determine 8 phenolic acids, 3 flavonols, and 4 anthocyanins in black rice wine. First, we clean samples with OASIS HLB cartridges and optimized extraction parameters. Next, we performed separation on a SHIM-PACK XR-ODS column (I.D. 3.0 mm × 75 mm, 2.2 μm particle size) with a gradient elution of 50% aqueous acetonitrile (V/V) and water, both containing 0.2% formic acid. We used multiple-reaction monitoring scanning for quantification, with switching electrospray ion source polarity between positive and negative modes in a single chromatographic run. We detected 15 phenolic compounds properly within 38 min under optimized conditions. Limits of detection ranged from 0.008 to 0.030 mg/L, and average recoveries ranged from 60.8 to 103.1% with relative standard deviation ≤8.6%. We validated the method and found it to be sensitive and reliable for quantifying phenolic compounds in rice wine matrices.

PRACTICAL APPLICATION

This study developed a new, reliable HPLC-MS/MS method for simultaneous determination of 15 bioactive components in black rice wine. This method was validated and found to be sensitive and reliable for quantifying phenolic compounds in rice wine.

Antiurease activity of plants growing in the Czech Republic

The antiurease activity of the aqueous extracts of 42 plants growing in the Czech Republic was investigated. A phenol-hypochlorite reaction was used for the determination of ammonia produced by urease. The inhibitory activity of the extracts at a concentration of 0.2 mg/mL varied from 17.8% to 80.0%. Extracts from six Potentilla species expressed inhibitory activity against jack bean urease. They were further investigated for their phenolic constituents and the major compounds were subjected to molecular docking. The results revealed that both jack bean urease and Helicobacter pylori urease were inhibited by quercetin-3-O-β-D-galactopyranoside-6″-gallate (1), myricetin-3-O-β-D-glucuronide (2), tiliroside (3) and B-type procyanidin (4). The antiurease activity of the investigated Potentilla species is probably due to the presence of complex phenolic constituents such as flavonoid glycosides and catechin dimers.

Antioxidant and cytotoxic activities of Centella asiatica (L) Urb

In the present study, the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents, antioxidant [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay] and cytotoxic activities of an aqueous extract (AE) of Centella asiatica leaves were investigated. The aqueous extract (50 g/L) was obtained by infusion followed by cold maceration for 24 h. The levels of phenolic and flavonoid compounds were 2.86 g/100 g and 0.361 g/100 g, respectively. The AE showed elevated DPPH scavenging activity, with an IC₅₀ value of 31.25 μg/mL. The AE had a promising activity against mouse melanoma (B₁₆F₁), human breast cancer (MDA MB-231) and rat glioma (C₆) cell lines, with IC₅₀ values of 698.0, 648.0 and 1000.0 μg/mL, respectively. A positive correlation was established between the level of flavonoids, antioxidant and antitumor activities.

Quantification of phenolic constituents and antioxidant activity of Pterodon emarginatus vogel seeds

In the present study the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents and the antioxidant activity of Pterodon emarginatus seeds were investigated in several samples prepared with different extraction procedures: essential oil (EO) using a Clevenger-type apparatus; hexanic (HF), ethyl acetate (EAF), buthanolic (BF) and methanolic (MF) fractions using Soxhlet extraction, and extracts (1 g/extract) obtained from different methods: reflux 80°C/30 min, ultrasound/30 min, static maceration/48 h and heating plate 100°C/45 min. These extracts were prepared using water or ethanol/water at 30:70 v/v, 50:50 v/v or 70:30 v/v. Antioxidant activity [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH)] was tested only in the fractions obtained from Soxhlet extraction. The extract obtained from reflux using ethanol/water (70:30, v/v) showed the highest phenolic constituents level. The EAF, BF and MF showed DPPH scavenging activities with IC₅₀=163.22, 18.89 and 10.15 μg/ml, respectively.

Evaluation of the botanical authenticity and phytochemical profile of black cohosh products by high-performance liquid chromatography with selected ion monitoring liquid chromatography-mass spectrometry

Black cohosh (Actaea racemosa L., syn. Cimicifuga racemosa L.) has become increasingly popular as a dietary supplement in the United States for the treatment of symptoms related to menopause, but the botanical authenticity of most products containing black cohosh has not been evaluated, nor is manufacturing highly regulated in the United States. In this study, 11 black cohosh products were analyzed for triterpene glycosides, phenolic constituents, and formononetin by high-performance liquid chromatography-photodiode array detection and a new selected ion monitoring liquid chromatography-mass spectrometry method. Three of the 11 products were found to contain the marker compound cimifugin and not cimiracemoside C, thereby indicating that these plants contain Asian Actaea instead of black cohosh. One product contained both black cohosh and an Asian Actaea species. For the products containing only black cohosh, there was significant product-to-product variability in the amounts of the selected triterpene glycosides and phenolic constituents, and as expected, no formononetin was detected.