Evaluation of Antioxidant,Antibacterial and Enhancement of Antibiotic Action by Punica granatum Leaves Crude Extract and Enriched Fraction against Multidrug-Resistant Bacteria

The aim of this study was to evaluate the phytochemical composition, antioxidant, and antimicrobial potential of crude extract and fractions of Punica granatum leaves. The extract was produced by turbo extraction, after which hexanic, ethyl acetate, and aqueous fractions were obtained by partitioning. The chemical analyses were performed by thin layer chromatography and high-performance liquid chromatography, and the antioxidant activities were assayed by DPPH^. and ABTS^.+. Minimal inhibitory and bactericidal concentrations (MIC/MBC) were applied to twenty-two bacteria. Most strains susceptible to extract/fractions and resistant to antibiotics were selected, and ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with the ethyl acetate fraction (EAF) against multidrug-resistant strains in modulatory and checkboard models. The data from chromatographic analyses showed flavonoids and tannins in the extract, as well as the enrichment of EAF in phenols, mainly flavonoids. The flavonoids were connected to the electron transfer activity demonstrated in the DPPH^. and ABTS^.+ assays. Gram-positive strains are more susceptible to EAF. The subinhibitory concentrations of P. granatum enhanced the antimicrobial activity of the agents and reduced the EAF individual MIC, and the combination of EAF and antibiotics demonstrated a synergistic effect. These results present a promising approach for developing a therapy in which antioxidant extracts and fractions can be used in combination with antibiotics.     

Volatile Composition and Biological Activities of the Leaf Essential Oil from Zanthoxylum limoncello Grown in Oaxaca,México

Zanthoxylum limoncello is a native plant from southern Mexico which is used as a timber source, condiment and as a traditional medicine. Herein, we report on the volatile content of the leaf essential oil and its biological activities. The annual essential oils (2015–2018) contained volatile organic compounds which exhibited a moderate growth inhibitory activity against H. pylori ATCC 53504 (MIC 121.4–139.7 μg mL^?1), 26695 (MIC 85.5–94.9 μg mL^?1) and J99 (MIC 94.7–110.4 μg mL^?1). These hydrodistillates contained 2‐undecanone (31.6–36.8 %; MIC 185.3–199.2 μg mL^?1) and 2‐undecenal (25.1–35.7 %; MIC 144.8–111.3 μg mL^?1) as the most abundant compounds which were partially involved in the anti‐H. pylori activity. The human ornithine decarboxylase enzyme (ODC1), which shows increased activity in several cancer types, was non‐competitively inhibited (V_max 2.7>0.8 K_cat s^?1) by the essential oil of Z. limoncello as well as by 2‐undecanone and 2‐undecenal in accordance to in vitro kinetic studies. In silico calculations strongly suggest that the carbonyl group of these oxygenated hydrocarbons interacts with both Asn319 and Ala39 at the subunit A of ODC1. Considering that Ala39 is located close to Asn44, a crucial amino acid of the ODC's allosteric site, the non‐competitive inhibition of the enzyme by 2‐undecanone and 2‐undecenal is endorsed. Finally, the essential oil of Z. limoncello and its main volatiles showed a significant (p<0.01) and prolonged repellent effect against Aedes aegypti.     

Essential Oil Compositions and Antibacterial and Antioxidant Activities of Five Lavandula stoechas Cultivars Grown in Thailand

The essential oils of five Lavandula stoechas cultivars grown in Thailand were characterized for their volatile compounds using GC‐FID and GC/MS methods as well as screened for antibacterial and antioxidant activities. Dried aerial parts, including flowers and stems from each cultivar, were subjected to hydrodistillation for 4 h. The essential oil yields were 0.18 %–0.82 % w/w. Of the 95 compounds detected and identified, 1,8‐cineole, fenchone, and camphor were considered the major compounds. Essential oil from each cultivar demonstrated different patterns of antibacterial activity and a variety of antioxidant properties. The highest antibacterial activity, MIC=0.39 mg mL^?1, was observed from the essential oil of L. stoechas ‘major’ (against Klebsiella pneumoniae and Salmonella typhimurium) and the essential oil of L. stoechas ‘white lavender’ (against S. typhimurium). The essential oil of L. stoechas×viridis ‘St. Brelade’ possessed the highest antioxidant capacity, as determined by the DPPH and ABTS assays (IC₅₀ of 67.65 and 89.26 mg mL^?1, respectively). The results indicated that some of these essential oils could be used as key ingredients in lavender oil products in Thailand to increase their therapeutic efficacy, depending on their intended application.     

In vitro Biological Activities of Seed Essential Oils from the Cameroonian Spices Afrostyrax lepidophyllus Mildbr. and Scorodophloeus zenkeri Harms Rich in Sulfur‐Containing Compounds

The chemical composition of the essential oils obtained from the seeds of bush onion (Afrostyrax lepidophyllus) and tropical garlic tree (Scorodophloeus zenkeri), plants used as spices in the traditional African cuisine, was determined by GC‐FID and GC/MS analyses. Moreover, in vitro biological properties of the oils, namely, the cytotoxic, antioxidant, and antimicrobial activities, were investigated by the MTT, the DPPH^. and ABTS^.+ scavenging, and the agar disc‐diffusion methods, respectively. Both oils were composed mainly by S‐containing compounds, accounting for 91.0–96.1% of the total oil compositions, which provided them the typical garlic‐ and onion‐like odors of spices. The predominant compound in both oils, 2,4,5,7‐tetrathiaoctane ( 1 ; 51.5–52.9%), was isolated by preparative TLC and structurally elucidated by ¹H‐ and ¹³C‐NMR data. The oils exhibited a strong inhibitory effect on the growth of human cancer cells, namely, T98G (human glioblastoma multiforme cell line), MDA‐MB 231 (human breast adenocarcinoma cell line), A375 (human malignant melanoma cell line), and HCT116 (human colon carcinoma cell line) cells, and a good DPPH^.‐ and ABTS^.+‐scavenging activity, while the antimicrobial effects were negligible. The volatile compositions of A. lepidophyllus and S. zenkeri oils supported their use as odorous spices. The significant inhibition activities detected make these oils worthy of further investigation as promising chemopreventive agents to be exploited in the African pharmaceutical market.     

A New Type of Anatolian Propolis: Evaluation of Its Chemical Composition,Activity Profile and Botanical Origin

This study was undertaken to analyze the phenolic profiles of 19 propolis samples from Turkey by using a high‐performance thin‐layer chromatographic (HPTLC) method in order to identify their plant origins. Furthermore, their antioxidant and antimicrobial activity profiles were comparatively evaluated. For the appraisal of antioxidant potential, total phenolic (TPC) and total flavonoid contents (TFC) of propolis samples were firstly determined and then their effects on free radicals were evaluated by FRAP, ABTS^.+, CUPRAC, DPPH^. and HPTLC‐DPPH^. methods. Antimicrobial activity of propolis samples against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 11229) and Candida albicans ATCC 10231 were determined by disc diffusion and broth dilution methods. HPTLC fingerprinting analyses revealed that O‐type (botanical origin from Populus nigra L.) was the primarily available propolis type in Turkey. Moreover, 3‐O‐methylquercetin (3MQ) rich propolis was identified as a new propolis type for the first time. Principal component analysis (PCA) indicated that 3MQ‐type propolis differs from the O‐type. Antioxidant activity studies showed that O‐type of propolis possesses higher antioxidant effect than the other tested propolis types. Quercetin, caffeic acid, caffeic acid phenethyl ester (CAPE) and galangin were determined to contribute significantly to the antioxidant potential of O‐type propolis among others. Propolis extracts exerted moderate antimicrobial activity against the tested microorganisms with MIC values between the ranges of 128–512 μg/mL.     

Analysis of Chemical Composition and Assessment of Antioxidant,Cytotoxic and Synergistic Antibacterial Activities of Essential Oils from Different Plant Parts of Piper boehmeriifolium

The essential oils (EOs) from leaves, stems, and whole plant of Piper boehmeriifolium were analyzed using GC/FID and GC/MS. The main constituents of P. boehmeriifolium EOs were β‐caryophyllene, caryophyllene oxide, β‐elemene, spathulenol, germacrene D, β‐selinene, and neointermedeol. The antioxidant potential of the EOs were determined using DPPH^?, ABTS^?+ and FRAP assays. In ABTS^?+ assay, the leaf oil exhibited a remarkable activity with an IC₅₀ value of 7.36 μg/mL almost similar to BHT (4.06 μg/mL). Furthermore, the antibacterial activity of the oils as well as their synergistic potential with conventional antibiotics were evaluated using microdilution and Checkerboard assays. The results revealed that the oils from different parts of P. boehmeriifolium inhibited the growth of all tested bacteria and the minimum inhibitory concentrations were determined to be 0.078 – 1.250 mg/mL. In combination with chloramphenicol or streptomycin, the oils showed significant synergistic antibacterial effects in most cases. Besides, the results of MTT assay indicated that the oil of the whole plant exhibited significant cytotoxic activities on human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF‐7). In summary, the P. boehmeriifolium oils could be regarded as a prospective source for pharmacologically active compounds.     

Effect of Seasonal and Regional Variations on Phenolic Compounds of Deverra scoparia (Flowers/Seeds) Methanolic Extract and the Evaluation of Its in Vitro Antioxidant Activity

The widespread use of Deverra scoparia Coss. & Durieu in Algerian folk‐medicine as a remedy can be relatively attributed to its total phenolic compounds. The current study aimed to provide a scientific basis for optimal collection and usage of Deverra scoparia Coss. & Durieu plant. Hence, 37 samples were gathered from nine sites in Algeria during two seasons 2016 and 2017, then exposed to a green extraction. Total phenolic (TPC), flavonoid (FC) and condensed tannins (CTC) content were estimated spectrophotometrically. The antioxidant activity was measured using five different methods, DPPH^., ABTS^.+, FRAP, CUPRAC and Fe²⁺‐chelating. The results have revealed considerable amounts of TPC varied from 804 to 1544 mg GAE/100 g dry matter, FC started from 187 up to 410 mg QE/100 g dry matter and CTC varied from 111 to 394 mg CE/100 g dry matter. The best IC₅₀ values (μg/mL) of DPPH^., ABTS^?+, FRAP, CUPRAC and Fe²⁺‐chelating tests were 56.62, 5.41, 21.26, 52.93 and 78.10, respectively. Moreover, high correlations were found between CTC and most of the antioxidant tests. Hence, CTC are suggested to be the principal group of antioxidant activity in Deverra scoparia Coss. & Durieu extracts.     

Phytochemical Profiles and Antioxidant Activity of Rehmannia glutinosa from Different Production Locations

The chemical components and antioxidant activity of 16 Rehmannia glutinosa samples were investigated to reveal the high‐quality raw resource for pharmaceutical products. 22 main chemical components were detected with significant content differences (P<0.05). The contents of 14 substances reached the maximum in S1 sample such as catalpol (6.74 mg g^?1), rehmaionoside A (1.93 mg g^?1) and rehmannioside D (5.13 mg g^?1). However, the content distribution of the other eight substances had no obvious change regulation. Three antioxidant evaluation methods commonly showed that S1 sample had strong antioxidant activity with a low IC₅₀ value of 0.022 mg mL^?1, a high ABTS value of 524.196 μmol equiv. Trolox g^?1, and a high FRAP value of 200.517 μmol equiv. Trolox g^?1. Considered the medicinal value, S1 had high quality based on the present phytochemical profiles and antioxidant activity. These results also indicated that the root extracts of R. glutinosa could become useful supplement for pharmaceutical products as new antioxidant agents.     

Polyphenol Characterization,Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark

In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel .) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP‐LC‐DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose‐dependent antioxidant and free‐radical scavenging activity, expressed as half‐maximal inhibitory concentration (IC₅₀): Oxygen radical absorbance capacity (ORAC, IC₅₀ 1.78 μg mL^?1)>Trolox equivalent antioxidant capacity (TEAC, IC₅₀ 3.47 μg mL^?1)>2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH, IC₅₀ 5.83 μg mL^?1)>β‐carotene bleaching (IC₅₀ 11.58 μg mL^?1)>Ferric reducing antioxidant power (FRAP, IC₅₀ 17.28 μg mL^?1). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC₅₀ 77.44 μg mL^?1), l ‐DOPA auto‐oxidation (IC₅₀ 39.58 μg mL^?1) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.     

Optimization of growing conditions for pigments production from microalga Navicula incerta using response surface methodology and its antioxidant capacity

Navicula incerta is a marine microalga distributed in Baja California, México, commonly used in aquaculture nutrition, and has been extended to human food, biomedical, and pharmaceutical industries due to its high biological activity. Therefore, the study aimed to optimize culture conditions to produce antioxidant pigments. A central composite experimental design and response surface methodology (RSM) was employed to analyze the best culture conditions. The medium (nitrogen-deficient concentrations), salinity (PSU = Practical Salinity Unity [g/kg]), age of culture (days), and solvent extraction (ethanol, methanol, and acetone) were the factors used for the experiment. Chlorophyll a (Chl a) and total carotenoids (T-Car), determined spectroscopically, were used as the response variables. The antioxidant capacity was evaluated by DPPH^? and ABTS^?+ radical inhibition, FRAP, and anti-hemolytic activity. According to the overlay plots, the optimum growth conditions for Chl a and T-Car production were the following conditions: medium = 0.44 mol·L^-1 of NaNO₃, salinity = 40 PSU, age of culture: 3.5 days, and solvent = methanol. The pigment extracts obtained in these optimized conditions had high antioxidant activity in ABTS^?+ (86.2–92.1% of inhibition) and anti-hemolytic activity (81.8–96.7% of hemolysis inhibition). Low inhibition (33–35%) was observed in DPPH^?. The highest value of FRAP (766.03 ± 16.62 μmol TE/g) was observed in the acetonic extract. The results demonstrated that RSM could obtain an extract with high antioxidant capacity with potential applications in the biomedical and pharmaceutical industry, which encourages the use of natural resources for chemoprevention of chronic-degenerative pathologies.     

Composition,Antibiofilm, and Antibacterial Potential of Volatile Oils from Geopropolis of Different Stingless Bees’ Species**

We aimed to characterize and investigate the antibacterial potential of the native stingless bees geopropolis volatile oils (VO) for the search of potentially new bioactive compounds. Geopropolis samples from Melipona bicolor schencki, M. compressipes manaosensis, M. fasciculata, M. quadrifasciata, M. marginata and M. seminigra merrillae were collected from hives in South Brazil. VO were obtained by hydrodistillation and characterised by gas chromatography coupled to mass spectrometry (GC/MS). Antimicrobial activity was assessed by microplate dilution method. The lowest MIC against cell walled bacteria was 219±0 μg mL⁻¹ from M. quadrifasciata geopropolis VO with Staphylococcus aureus. The M. b. schencki geopropolis VO minimal inhibition concentration (MIC) was 424±0 μg mL⁻¹ against all the mycoplasma strains evaluated. Fractionation resulted in the reduction of 50 % of the MIC value from the original oil. However, its compounds’ synergism seems to be essential to this activity. Antibiofilm assays demonstrated 15.25 % eradication activity and 13.20 % inhibition of biofilm formation after 24 h for one subfraction at 2× its MIC as the best results found. This may be one of the essential mechanisms by which geopropolis VOs perform their antimicrobial activity.     

Chemical Variability and Antioxidant Activity of Limbarda crithmoides L. Essential Oil from Corsica

The chemical compositions of 25 Corsican Limbarda crithmoides ssp. longifolia essential oils were investigated for the first time using GC‐FID, GC/MS, and NMR analyses. Altogether, 65 compounds were identified, accounting for 90.0–99.3% of the total oil compositions. The main components were p‐cymene ( 1 ; 15.1–34.6%), 3‐methoxy‐p‐cymenene ( 4 ; 11.8–28.5%), 2,5‐dimethoxy‐p‐cymenene ( 5 ; 5.9–16.4%), thymol methyl ether ( 6 ; 1.3–14.9%), α‐phellandrene ( 2 ; 0.9–11.9%), and α‐pinene ( 3 ; 0.2–13.4%). The chemical variability of the Corsican oil samples was studied using multivariate statistical analysis, which allowed the discrimination of two main clusters. A direct correlation between the water salinities of the plant locations and the chemical compositions of the L. crithmoides essential oils was evidenced. Indeed, essential oils rich in 1 (30.4–34.6%) were found in samples growing in the wetlands of the southern oriental coast, which exhibit high salinity levels (24.4±0.2–33.9±0.2 ppt), and essential oils with lower contents of 1 (15.1–27.3%) were isolated form samples growing in the wetlands of northern Corsica, which exhibit lower salinity levels (10.90±0.20–15.47±0.15 ppt). The antioxidant potential of L. crithmoides essential oil was also investigated, by assessing the DPPH^.‐ and ABTS^.+‐scavenging activities and the reducing power of ferric ions, and was found to be interesting. Moreover, using bioassay‐guided fractionation of the essential oil, a higher antioxidant activity was obtained for the oxygenated fraction and both ester and alcohol subfractions.     

Preparation and Evaluation of Gallate Ester Derivatives Used as Promising Antioxidant and Antibacterial Inhibitors

Many gallate esters have been applied as food additives due to their good biological properties. Herein, nine novel gallate ester derivatives were synthesized by a Friedel-Crafts alkylation reaction and characterized by melting point (m.p.), infrared (IR) spectroscopy, nuclear magnetic resonance (¹H- and ¹³C-NMR) spectra, and high-resolution mass spectrometry (HR-ESI-MS). Their antioxidant and antibacterial activities were measured using a series of classical assays. Studies found that the products showed favorable antioxidant and antibacterial activities. Their 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH ^⋅ ) scavenging effect IC₅₀ values were less than 5.00 μg mL⁻¹ and their reducing power was not less than that of vitamin C (Vc). Furthermore, the antibacterial results showed that the minimum inhibitory concentration (MIC) values of the products were not greater than 8.00 μg mL⁻¹, and their antibacterial rates were over 95 % at 300 μg mL⁻¹. The above data add valuable and novel information that gallate ester derivatives can be considered potential food additives to address food safety issues because of their high biological activity and health benefits.     

Phenolic Composition,Anti‐Inflammatory,Antioxidant, and Antimicrobial Activities of Alchemilla mollis (Buser) Rothm.

The current study was designed to evaluate the antioxidant, anti‐inflammatory and antimicrobial activities of Alchemilla mollis (Buser ) Rothm . (Rosaceae) aerial parts extracts. Chemical composition was analyzed by spectrophotometric and chromatographic (HPLC) techniques. The antioxidant properties assessed included DPPH^· and ABTS^·+ radical scavenging, β‐carotene‐linoleic acid co‐oxidation assay. Antimicrobial activity was evaluated with disc diffusion and micro dilution method. In order to evaluate toxicity of the extracts, with the sulforhodamine B colorimetric assay L929 cell line (mouse fibroblast) was used. The anti‐inflammatory activities of the potent antioxidant extracts (methanol, 70% methanol, and water extracts) were determined by measuring the inhibitory effects on NO production and pro‐inflammatory cytokine TNF‐α levels in lipopolysaccharide stimulated RAW 264.7 cells. 70% methanol and water extracts which were found to be rich in phenolic compounds (184.79 and 172.60 mg GAE/g extract) showed higher antioxidant activity. Luteolin‐7‐O‐glucoside was the main compound in the extracts. Ethyl acetate and 70% methanol extracts showed higher antibacterial activity against Staphylococcus aureus and Salmonella enteritidis with MIC value of 125 μg/ml. 70% methanol extract potentially inhibited the NO and TNF‐α production (18.43 μm and 1556.22 pg/ml, respectively, 6 h).     

Essential Oil of Lepidium virginicum: Protective Activity on Anthracnose Disease and Preservation Effect on the Nutraceutical Content of Tamarillo Fruit (Solanum betaceum)

The essential oil from the annual plant Lepidium virginicum L. was chemically characterized in three consecutive years (2018–2020). The essential oils were evaluated in vitro and in situ on the causal agent of anthracnose in tamarillo fruits (Solanum betaceum). The main volatile constituents were phenylacetonitrile (>60 %), linalool (>10 %), limonene (>7 %) and α-terpineol (>5 %). The essential oil (MIC, 19–30 μg mL⁻¹), phenylacetonitrile (MIC, 45 μg mL⁻¹) and α-terpineol (MIC, 73 μg mL⁻¹) caused a significant inhibition in the conidial viability from a wild strain of Colletotrichum acutatum, which was isolated and identified as a causal agent of anthracnose. The inoculation of conidia from C. acutatum in non-symptomatic tamarillo fruits, followed by the in situ treatment with different concentrations of the essential oil (>30 μg mL⁻¹), phenylacetonitrile and α-terpineol, significantly (p<0.01) avoided the degradation of anthocyanins (delphinidin 3-O-rutinoside, cyanidin 3-O-rutinoside and pelargonidin 3-O-rutinoside) and carotenoids (β-cryptoxanthin and β-carotene) as well as retarded yellowing and necrosis triggered by anthracnose at least for 10 days. Our results suggest the potential use of the essential oil from L. virginicum as a natural component to preserve the nutraceutical content of tamarillo fruits against C. acutatum infection.     

Synthesis,Antioxidant Activity and Cytotoxicity of N-Functionalized Organotellurides

The use of antioxidants is the most effective means to protect the organism against cellular damage caused by oxidative stress. In this context, organotellurides have been described as promising antioxidant agents for decades. Herein, a series of N-functionalized organotellurium compounds has been tested as antioxidant and presented remarkable activities by three different in vitro chemical assays. They were able to reduce DPPH radical with IC₅₀ values ranging from 5.08 to 19.20?µg?mL^?1, and some of them also reduced ABTS⁺ radical and TPTZ-Fe³⁺ complex in ABTS⁺ and FRAP assays, respectively. Initial structure-activity relationship discloses that the nature of N-substituent strongly influenced both activity and cytotoxicity of the studied compounds. Furthermore, radical scavenging activities of N-functionalized organotellurides have been compared with those of their selenilated congeners, demonstrating that the presence of tellurium atom has an essential role in antioxidant activity.     

Chemically characterised Artemisia nilagirica (Clarke) Pamp. essential oil as a safe plant-based preservative and shelf-life enhancer of millets against fungal and aflatoxin contamination and lipid peroxidation

Abstract

The study recommends the Artemisia nilagirica (Clarke) Pamp. essential oil (ANEO) as plant-based shelf-life enhancer of millets against fungal, aflatoxin B₁ (AFB₁) contamination and lipid peroxidation with favourable safety profile. Chemical characterisation of ANEO through GC-MS, recorded 1,5-heptadiene-4-one,3,3,6-trimethyl (32.72%)as the main compound, followed by Artemisia alcohol (13.40%), alpha lonone (4.55%), benzene, methyl (1-methylethyl) (2.97%) and 1-cyclohexene-1-carboxaldehyde,4-(1-methylethyenyl) (2.23%). The mycoflora analysis of millet samples showed Aspergillus flavus strain[LHP(R)-5] as the most AFB₁ secreting strain. The ANEO inhibited growth and AFB₁ production by the toxigenic strain at 1.4 and 1.0?µL?mL^?1, respectively, and also possess broad fungitoxic spectrum. The decrement in membrane ergosterol content, enhanced leakage of cellular Ca²⁺, K⁺ and Mg²⁺ ions along with SEM and TEM study of ANEO-treated cell denotes plasma membrane as antifungal site of action. The ANEO also showed strong antioxidant activity as determined by DPPH^? and ABTS^?+ assays having IC₅₀ value 2.51 and 1.07?µL?mL^?1, respectively. More than 70.78% protection of Ragi samples from fungal contamination was observed during in situ trial. The ANEO showed favourable safety profile with high LD₅₀ value (7528.10?µL?kg^?1) for male mice and also exhibited non-phytotoxicity for Ragi seeds germination.     

Extraction and Antioxidant Activities of Magnolia kwangsiensis Figlar & Noot. Leaf Polyphenols

Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot . The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL?g^?1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH ^? and ^? OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ^? OH. In term of ^? OH scavenging activity, the IC₅₀ value of NKA‐9 purification was 0.335 mg mL^?1, equivalent to 35.23 % of V_C. The IC₅₀ values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL^?1, equivalent to 60.99 % and 87.07 % of V_C. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage.     

Bioactive Constituents of Juniperus turbinata Guss. from La Maddalena Archipelago

A comprehensive phytochemical study of Juniperus turbinata (Cupressaceae) collected from La Maddalena Archipelago (Sardinia, Italy) is reported. Both the essential oil and the ethanolic extract obtained from the aerial parts were analyzed. The essential oil appears to belong to a new chemotype compared to other Mediterranean juniper accessions, as it was favored by geographic isolation of the isles. It showed a low content of monoterpene hydrocarbons and α‐terpineol, ent‐manoyl oxide, 1,10‐di‐epi‐cubenol as the major constituents. The ethanolic fraction contained mainly diterpenoids. Among these, 15‐formyloxyimbricatolic acid ( 7 ) is a new natural product since it has hitherto been obtained only by synthetic route. The phenolic fraction contained biflavonoids: cupressuflavone ( 9 ), followed by minor amounts of amentoflavone ( 10 ) and hinokiflavone ( 11 ). The essential oil and six purified compounds ( 1 – 4 , 8 and 9 ) were assessed for biological activities, namely antioxidant (assessed by DPPH^·, ABTS^·+ and FRAP methods) and cytotoxic effects towards selected human tumor cell lines (MDA‐MB 231, A375 and HCT116 cells). Compound 3 exhibited higher radical scavenging activity against ABTS^·+ radical than the reference Trolox. Noteworthy, compound 8 showed powerful effects towards tumor cell lines, with IC₅₀ values in the range of 0.060 – 0.201 μm , which make it a promising anticancer drug candidate.     

Orthogonal Test Design for Optimization of the Extraction of Polysaccharides from Inonotus cuticularis and Their Antioxidant Activities

Medical fungi polysaccharides belong to a very important species of biological macromolecules, which are the basic substances that effectively maintain and ensure the normal operation of biological life activities. However, research on extraction and biological activity of Inonotus cuticularis polysaccharides has never been reported. In this study, the optimum yield of Inonotus cuticularis polysaccharides was determined by the orthogonal experimental design. The highest yield of 3.10±0.06 % was obtained with extraction temperature of 80 °C, extraction time of 150 min, and water to raw material ratio of 30 mL/g and repeated twice. After deproteinization for 5 times, the protein removal rate reached 70.10±1.75 %, and the content of polysaccharides and protein were 46.64 and 0.42 %. Infrared spectrometer indicated that Inonotus cuticularis polysaccharides are typical β‐pyranose with characteristic peaks of polysaccharides. Subsequently, the activities of scavenging free radicals for the deproteinated polysaccharides were studied. When the concentration of Inonotus cuticularis polysaccharides was 0.3 mg/mL, the scavenging activities of the sample on DPPH^., ^.OH, ABTS^.+ and O₂^.? reached 83.67±0.27, 65.21±4.82, 43.45±1.36 and 80.28±2.30 %, respectively, and the reducing power reached 0.46±0.01. The IC₅₀ values scavenging DPPH^., ^.OH, ABTS^.+ and O₂^.? were 0.139±0.13, 0.162±0.14, 0.317±0.30 and 0.121±0.10 mg/mL, respectively. Results showed that Inonotus cuticularis polysaccharides present potential stronger antioxidant activities, especially ^.OH scavenging activity and reducing power. Experimental results could provide research basis of Inonotus cuticularis polysaccharides for further exploitation and utilization.