Bioactivity and Mycochemical Profile of Extracts from Mycelial Cultures of Ganoderma spp.

Fungal mycelium cultures are an alternative to natural sources in order to obtain valuable research materials. They also enable constant control and adaptation of the process, thereby leading to increased biomass growth and accumulation of bioactive metabolites. The present study aims to assess the biosynthetic potential of mycelial cultures of six Ganoderma species: G. adspersum, G. applanatum, G. carnosum, G. lucidum, G. pfeifferi, and G. resinaceum. The presence of phenolic acids, amino acids, indole compounds, sterols, and kojic acid in biomass extracts was determined by HPLC. The antioxidant and cytotoxic activities of the extracts and their effects on the inhibition of selected enzymes (tyrosinase and acetylcholinesterase) were also evaluated. The total content of phenolic acids in the extracts ranged from 5.8 (G. carnosum) to 114.07 mg/100 g dry weight (d.w.) (G. pfeifferi). The total content of indole compounds in the extracts ranged from 3.03 (G. carnosum) to 11.56 mg/100 g d.w. (G. lucidum) and that of ergosterol ranged from 28.15 (G. applanatum) to 74.78 mg/100 g d.w. (G. adspersum). Kojic acid was found in the extracts of G. applanatum and G. lucidum. The tested extracts showed significant antioxidant activity. The results suggest that the analyzed mycelial cultures are promising candidates for the development of new dietary supplements or pharmaceutical preparations.     

Phytochemical Profiling,In Vitro Biological Activities,and In Silico Molecular Docking Studies of Dracaena reflexa

Dracaena reflexa, a traditionally significant medicinal plant, has not been extensively explored before for its phytochemical and biological potential. The present study was conducted to evaluate the bioactive phytochemicals and in vitro biological activities of D. reflexa, and perform in silico molecular docking validation of D. reflexa. The bioactive phytochemicals were assessed by preliminary phytochemical testing, total bioactive contents, and GC-MS analysis. For biological evaluation, the antioxidant (DPPH, ABTS, CUPRAC, and ABTS), antibacterial, thrombolytic, and enzyme inhibition (tyrosinase and cholinesterase enzymes) potential were determined. The highest level of total phenolic contents (92.72 ± 0.79 mg GAE/g extract) was found in the n-butanol fraction while the maximum total flavonoid content (110 ± 0.83 mg QE/g extract) was observed in methanolic extract. The results showed that n-butanol fraction exhibited very significant tyrosinase inhibition activity (73.46 ± 0.80) and acetylcholinesterase inhibition activity (64.06 ± 2.65%) as compared to other fractions and comparable to the standard compounds (kojic acid and galantamine). The methanolic extract was considered to have moderate butyrylcholinesterase inhibition activity (50.97 ± 063) as compared to the standard compound galantamine (53.671 ± 0.97%). The GC-MS analysis of the n-hexane fraction resulted in the tentative identification of 120 bioactive phytochemicals. Furthermore, the major compounds as identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (tyrosinase, acetylcholinesterase, and butyrylcholinesterase enzymes). The results of this study suggest that Dracaena reflexa has unquestionable pharmaceutical importance and it should be further explored for the isolation of secondary metabolites that can be employed for the treatment of different diseases.     

Comparison of sterols and fatty acids in two species of <Emphasis Type="Italic">Ganoderma</Emphasis>

Background  

Two species of Ganoderma, G. sinense and G. lucidum, are used as Lingzhi in China. Howerver, the content of triterpenoids and polysaccharides, main actives compounds, are significant different, though the extracts of both G. lucidum and G. sinense have antitumoral proliferation effect. It is suspected that other compounds contribute to their antitumoral activity. Sterols and fatty acids have obvious bioactivity. Therefore, determination and comparison of sterols and fatty acids is helpful to elucidate the active components of Lingzhi.     

Documentation of bioactive principles of the exudate gel (EG) from the stem of Caralluma retrospiciens (Ehrenb) and in vitro antibacterial activity – Part A

Caralluma retrospiciens (Ehrenb) is a desert plant widely distributed in the hilly semi-desert regions of southern part of Saudi Arabia. The exudate gel (EG) from the stem of plant is occasionally used for wound healing by the people of the southern part of Saudi Arabia. This study investigated the phytochemical composition, FT-IR, GC–MS spectral analysis and in vitro antibacterial activity of the EG from the stem of C. retrospiciens (Ehrenb). The plant C. retrospiciens (Ehrenb.) was collected from the hills of Rijal Almaa, a heritage village of Saudi Arabia. The EG was isolated from the stem of C. retrospiciens (Ehrenb.). Physical parameters such as viscosity and zeta potential (ZP) were determined. Phytochemical analysis, FT-IR and GC–MS spectroscopy analysis were performed to determine the bio active constituents. The antibacterial activity of the isolated gel was performed by in vitro agar well diffusion technique. The study demonstrated that the viscosity and ZP of EG influenced the efficacy of antibacterial spectral properties. The FT-IR spectroscopy of the EG showed various functional groups at 3278.29, 2951.16, 2840.44, 2527.55, 2161.67, 1647.40, 1450.06, 1406.7, 1286, 1108.34, 5536.63 cm⁻¹. Various pharmaceutically important chemical compounds were identified using GC–MS analysis. The bioactive compounds are “Sorbic Acid”, “Rhodopsin”, “1-Heptatriacotanol”, “Oxiraneundecanoic acid, 3-pentyl-, methyl ester, trans”, “Cholestan-3-ol, 2-methylene-, (3á,5à)”, “Benzoic acid”, “3-pentyl-, methyl ester trans”, “Hexanoic acid, 2-ethyl-, oxybis (2,1-ethanediyloxy-2,1-ethanediyl) ester”, etc. The antibacterial effect of the EG showed a wide spectrum of activity against the screened human pathogenic bacteria. The results demonstrate the bioactive principles of EG from C. retrospiciens (Ehrenb.) exerts the antibacterial properties in vitro.     

The Chemical Profiling of Essential Oils from Different Tissues of Cinnamomum camphora L. and Their Antimicrobial Activities

Cinnamomum camphora L. is grown as an ornamental plant, used as raw material for furniture, as a source of camphor, and its essential oil can be used as an important source for perfume as well as alternative medicine. A comparative investigation of essential oil compositions and antimicrobial activities of different tissues of C. camphora was carried out. The essential oils were extracted by hydrodistillation with a Clevenger apparatus and their compositions were evaluated through gas chromatography-mass spectrometry (GC-MS), enantiomeric composition by chiral GC-MS, and antimicrobial properties were assayed by measuring minimum inhibitory concentrations (MICs). Different plant tissues had different extraction yields, with the leaf having the highest yield. GC-MS analysis revealed the presence of 18, 75, 87, 67, 67, and 74 compounds in leaf, branch, wood, root, leaf/branch, and leaf/branch/wood, respectively. The significance of combining tissues is to enable extraction of commercial quality essential oils without the need to separate them. The oxygenated monoterpene camphor was the major component in all tissues of C. camphora except for safrole in the root. With chiral GC-MS, the enantiomeric distributions of 12, 12, 13, 14, and 14 chiral compounds in branch, wood, root, leaf/branch, and leaf/branch/wood, respectively, were determined. The variation in composition and enantiomeric distribution in the different tissues of C. camphora may be attributed to the different defense requirements of these tissues. The wood essential oil showed effective antibacterial activity against Serratia marcescens with an MIC of 39.1 μg/mL. Similarly, the mixture of leaf/branch/wood essential oils displayed good antifungal activity against Aspergillus niger and Aspergillus fumigatus while the leaf essential oil was notably active against Trichophyton rubrum. C. camphora essential oils showed variable antimicrobial activities against dermal and pulmonary-borne microbes.     

The Isorhamnetin-Containing Fraction of Philippine Honey Produced by the Stingless Bee Tetragonula biroi Is an Antibiotic against Multidrug-Resistant Staphylococcus aureus

Honey exhibits antibacterial and antioxidant activities that are ascribed to its diverse secondary metabolites. In the Philippines, the antibacterial and antioxidant activities, as well as the bioactive metabolite contents of the honey, have not been thoroughly described. In this report, we investigated the in vitro antibacterial and antioxidant activities of honey from Apis mellifera and Tetragonula biroi, identified the compound responsible for the antibacterial activity, and compared the observed bioactivities and metabolite profiles to that of Manuka honey, which is recognized for its antibacterial and antioxidant properties. The secondary metabolite contents of honey were extracted using a nonionic polymeric resin followed by antibacterial and antioxidant assays, and then spectroscopic analyses of the phenolic and flavonoid contents. Results showed that honey extracts produced by T. biroi exhibits antibiotic activity against Staphylococcal pathogens as well as high antioxidant activity, which are correlated to its high flavonoid and phenolic content as compared to honey produced by A. mellifera. The bioassay-guided fractionation paired with Liquid Chromatography Mass Spectrometry (LCMS) and tandem MS analyses found the presence of the flavonoid isorhamnetin (3-methylquercetin) in T. biroi honey extract, which was demonstrated as one of the compounds with inhibitory activity against multidrug-resistant Staphylococcus aureus ATCC BAA-44. Our findings suggest that Philippine honey produced by T. biroi is a potential nutraceutical that possesses antibiotic and antioxidant activities.     

Triggering of the Antibacterial Activity of <Emphasis Type="Italic">Bacillus subtilis</Emphasis> B38 Strain against Methicillin-Resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

When cultured in minimal growth medium, the B38 strain of Bacillus subtilis did not exhibit any antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolate. Coculturing B38 strain with viable MRSA cells weakly increased antibacterial activity production (20 AU/ml). Addition of dead MRSA cells in a B38 culture, increased by 8-fold the B. subtilis strain antibacterial activity reaching 160 AU/ml against MRSA strain. This antibacterial activity recovered from cell-free supernatants was stimulated by an autoinducing compound which is sensitive to the action of proteinase K suggesting a proteinaceous nature. This compound was heat-stable till 80 °C and showed a molecular mass around 20 kDa as determined by SDS-PAGE. These results suggest that the production of antibacterial compounds by B38 strain is dependent on the amount of the autoinducing compound.     

Valorization of Okara by Enzymatic Production of Anti-Fungal Compounds for Plant Protection

Okara is a soybean transformation agri-food by-product, the massive production of which currently poses severe disposal issues. However, its composition is rich in seed storage proteins, which, once extracted, can represent an interesting source of bioactive peptides. Antimicrobial and antifungal proteins and peptides have been described in plant seeds; thus, okara is a valuable source of compounds, exploitable for integrated pest management. The aim of this work is to describe a rapid and economic procedure to isolate proteins from okara, and to produce an enzymatic proteolyzed product, active against fungal plant pathogens. The procedure allowed the isolation and recovery of about 30% of okara total proteins. Several proteolytic enzymes were screened to identify the proper procedure to produce antifungal compounds. Antifungal activity of the protein digested for 24 h with pancreatin against Fusarium and R. solani mycelial growth and Pseudomonas spp was assessed. A dose-response inhibitory activity was established against fungi belonging to the Fusarium genus. The exploitation of okara to produce antifungal bioactive peptides has the potential to turn this by-product into a paradigmatic example of circular economy, since a field-derived food waste is transformed into a source of valuable compounds to be used in field crops protection.     

Untargeted GC-MS Metabolomics applied to wild leaves and callus produced by plant tissue culture of Hibiscus sabdariffa L.

Hibiscus sabdariffa L. is a naturalized medicinal species in Brazil commonly called a “vinagreira” and is a member of the Malvaceae Juss. family, which has a rich potential of bioactive compounds presenting extracts with antioxidant, antibacterial, anti-inflammatory, hepatoprotective, antiviral, antidiabetic, and antiobesity, among others. The production of secondary metabolites of medicinal plants using biotechnological tools such as the culture of callus of plant tissues is increasingly being used to produce high-quality compounds under in vitro conditions. From this perspective, the objective of this work was to analyze the chemical compounds of the leaves and callus culture of H. sabdariffa using techniques of Gas Chromatography Coupled to the Mass Spectrum (GC-MS),. The analysis methodology used consisted of removal of liposoluble compounds, acid hydrolysis, and derivatization, all stages were submitted to ultrasonic-assisted agitation, using a reduced amount of biomass. Based on the results obtained in the study, a total of 38 metabolites identified by GC-MS analysis can be observed. Among the identified substances, protocatechuic acid (26A) stands out as the main constituent, with a relative abundance of 26.86% and 16.68% for leaves and callus of H. sabdariffa, respectively. The principal component analysis (PCA) allowed the discrimination of the chemical composition of each sample, being useful for the observation and detection of the compounds trends patterns. The analysis of the hierarchical group combined with the heat map represented the visual relationship between the samples of the data set indicating the values of higher and lower concentrations of chemical compounds respectively, confirming that protocatechuic acid is the most abundant, for the leaves and callus of H. sabdariffa, followed by eicosanoid and isocitric acid, produced only in callus. It was concluded that the GC-MS technique combined with chemometric tools, helped identify the diversity of the compounds present in the leaves and callus of H. sabdariffa and that callus culture enables the production of bioactive compounds continuously and uniformly in a controlled environment and free of contamination.     

Antioxidant,Antibacterial, and Antifungal Activities of the Ethanolic Extract Obtained from Berberis vulgaris Roots and Leaves

This work assessed the phenolic and flavonoid components and their antioxidant, antifungal, and antibacterial effects in the ethanolic extract of barberry leaf and roots. The antibactericidal activity of root and leaf extracts against pathogenic bacteria was tested using agar diffusion and microdilution broth production for the lowest inhibitory concentration (MIC). Berberis vulgaris root and leaf extracts inhibited Staphylococcus aureus ATCC9973, Escherichia coli HB101, Staphylococcus enteritis, and Escherichia coli Cip812. The disc assay technique was used to assess the bactericidal activity of the extracts versus both pathogenic Gram-positive and Gram-negative strains. Hydro alcoholic extract was more effective against bacterial than fungal strains. The results showed that Berberis vulgaris leaf and roots extract had similar antifungal activities. Berberis vulgaris root extract inhibited the mycelial growth of Penicillium verrucosum, Fusarium proliferatum, Aspergillus ochraceous, Aspergillus niger, and Aspergillus flavus. Berberis vulgaris root extract has excellent antioxidant, antibacterial, and antifungal effects. Berberis vulgaris exhibited antimicrobial activity in vitro, and MIC showed that Berberis vulgaris parts efficiently affected pathogens in vitro. In conclusion, both Berberis vulgaris roots and leaves have considerable antibacterial activity and can be used as a source of antibacterial, antioxidant, and bioactive compounds to benefit human health.     

Synthesis,Characterization, and Antimicrobial Assessment of Some Computationally Bioactive 1,2-Oxazole Derivatives

1,2-Oxazole derivatives 1–6 were designed and evaluated computationally to calculate the physicochemical properties and the bioactivity score by Mol-inspiration, and were determined to possess very good activity score. 1,2-Oxazoles were then synthesized, characterized by FT-IR, ¹H NMR and mass spectroscopy, and tested for antibacterial activity against the pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Proteus mirabilis). The antibacterial therapeutic effect strongly supported the prior computational results. Four synthesized compounds 2, 4–6 demonstrated antibacterial potential higher than the standard drug Ciprofloxacin.     

Secondary metabolites produced by fungi derived from a microbial mat encountered in an iron-rich natural spring

A collection of fungal isolates was obtained from a complex microbial mat, which occupied an iron-rich freshwater spring that feeds into Clear Creek, Golden, Colorado, USA. Two of the fungal isolates, a Glomeromycete (possibly Entrophospora sp.) and a Dothideomycete (possibly Phaeosphaeria sp.), were investigated for bioactive secondary metabolites. In total, six new compounds consisting of clearanols A-E (5, 6, 10-12) and disulochrin (7) were purified and their structures were determined. Disulochrin exhibited modest antibacterial activity against methicillin-resistant Staphylococcus aureus, whereas clearanol C showed weak inhibitory activity against Candida albicans biofilm formation.     

Essential Oils Extracted from Organic Propolis Residues: An Exploratory Analysis of Their Antibacterial and Antioxidant Properties and Volatile Profile

The industrial processing of crude propolis generates residues. Essential oils (EOs) from propolis residues could be a potential source of natural bioactive compounds to replace antibiotics and synthetic antioxidants in pig production. In this study, we determined the antibacterial/antioxidant activity of EOs from crude organic propolis (EOP) and from propolis residues, moist residue (EOMR), and dried residue (EODR), and further elucidated their chemical composition. The EOs were extracted by hydrodistillation, and their volatile profile was tentatively identified by GC-MS. All EOs had an antibacterial effect on Escherichia coli and Lactobacillus plantarum as they caused disturbances on the growth kinetics of both bacteria. However, EODR had more selective antibacterial activity, as it caused a higher reduction in the maximal culture density (D) of E. coli (86.7%) than L. plantarum (46.9%). EODR exhibited mild antioxidant activity, whereas EOMR showed the highest antioxidant activity (ABTS = 0.90 μmol TE/mg, FRAP = 463.97 μmol Fe²⁺/mg) and phenolic content (58.41 mg GAE/g). Each EO had a different chemical composition, but α-pinene and β-pinene were the major compounds detected in the samples. Interestingly, specific minor compounds were detected in a higher relative amount in EOMR and EODR as compared to EOP. Therefore, these minor compounds are most likely responsible for the biological properties of EODR and EOMR. Collectively, our findings suggest that the EOs from propolis residues could be resourcefully used as natural antibacterial/antioxidant additives in pig production.     

Integration of naturally bioactive thiazolium and 1,3,4-oxadiazole fragments in a single molecular architecture as prospective antimicrobial surrogates

Plant microbial diseases caused global production constraints have become one of the most challenging events, thus urgently needing to be addressed nowadays. To efficiently promote the discovery of promising antimicrobial surrogates, a type of 1,3,4-oxadiazole thioethers owning naturally bioactive thiazolium patterns was designed and fabricated. Antibacterial screening results revealed that title compounds could significantly inhibit the growth of pathogens Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri. And the related antibacterial efficacy was elevated by approximately 386-, 16-, and 24-folds comparing those of mainly used commercial agents bismerthiazol and thiodiazole copper. In vivo experiment suggested that A₉ could manage rice bacterial blight with the corresponding curative and protection efficiencies of 48.01% and 50.55% at 200 μg/mL. Moreover, SEM patterns and fluorescence spectra were performed to explore the possible antibacterial mechanism. Preliminary antifungal bioassays revealed that these molecules paraded broad-spectrum inhibition effects against three tested fungal strains. Considering the simple molecular skeleton and significant biological actions, title compounds can be further explored as potential antimicrobial surrogates for managing plant bacterial and fungal diseases.     

Chemical profiling of Aristolochia tagala Cham. leaf extracts by GC-MS analysis and evaluation of its antibacterial activity

Aristolochia tagala Cham. (Aristolochiaceae) is an underexplored medicinal plant traditionally used to treat snakebites, stomachaches, and poisonous bites. In this study, chemical profiling of the petroleum ether, chloroform, ethyl acetate, methanol, and hydro-alcoholic extracts of the plant was investigated by gas chromatography-mass spectrometry. The antibacterial activity of the plant was tested against ten bacterial strains using the agar disc diffusion and microdilution method. In total, forty two compounds were identified from the extracts with neophytadiene, palmitic acid, phytol, trans-δ9-octadecenoic acid, phytyl palmitate, phytyl tetradecanoate, ergost-5-en-3-ol, (3beta,24r)-,z,z-8,10-hexadecadien-1-ol, stigmasterol, and tetrapentacontane as major phytoconstituents. The hydro-alcoholic extract possessed maximum total phenolics (52.58 ± 06 mg GAE/g), total flavonoids (48.66 ± 91 QRE/g), total flavanols (67.20 ± 64 QRE/g) and vitamin E content (31.26 ± 0.05 mg ATE/g). For antibacterial activity, hydro-alcoholic extract of Aristolochia tagala effectively controlled the growth of bacterial strains such as Proteus valgaris (26.3 mm) and Pseudomonas aeruginosa (19.33 mm) and the same extract showed notable minimum inhibitory concentration (MIC) against the growth of bacteria like Escherichia coli (10.93 μg/ml) and Enterobacter aerogenes (43.7 μg/ml). It was determined that, hydro-alcoholic and methanolic extracts Aristolochia tagala leaf found to have a number of bioactive compounds with significant antibacterial activity against the pathogenic bacteria. Further investigations are necessary to isolate and characterize bioactives and to evaluate its therapeutic potential.     

Sambucus Nigra Extracts–Natural Antioxidants and Antimicrobial Compounds

Due to the health-promoting properties of elderberry fruits, which result from their rich chemical composition, this raw material is widely used in herbal medicine and the food industry. The aim of the study was to demonstrate the antibacterial activity of the elderberry fruit extracts. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The following phenolic acids were predominant: chlorogenic acid, sinapic acid, and t-cinnamic acid. Their average content was, respectively, 139.09, 72.84, 51.29 mg/g extract. Rutin and quercetin (their average content was 1105.39 and 306.6 mg/g extract, respectively) were the dominant flavonoids. The research showed that the elderberry polyphenol extracts exhibited activity against selected strains of bacteria within the concentration range of 0.5–0.05%. The following bacteria were the most sensitive to the extracts: Micrococcus luteus, Proteus mirabilis, Pseudomonas fragii, and Escherichia coli. Of the compounds under analysis, apigenin, kaempferol and ferulic, protocatechuic, and p-coumarin acids had the greatest influence on the high antibacterial activity of elderberry extracts. The results of the microbiological and chemical analyses of the composition of the extracts were analyzed statistically to indicate the bioactive compounds of the greatest antimicrobial significance.     

Improved Polysaccharide Production in Submerged Culture of Ganoderma lucidum by the Addition of Coixenolide

Polysaccharides from Ganoderma lucidum have various bioactivities and have been widely used as nutraceuticals and functional foods. Coixenolide was added into the media to enhance the production of mycelia biomass and polysaccharides in the submerged culture of G. lucidum in this work. The results showed that when a level of 0.2 % coixenolide was added at day 1, the biomass, exopolysaccharide, and intracellular polysaccharide reached 5.224, 0.222, and 0.399 g l^?1, respectively, which were 1.39-fold, 2.58-fold, and 2.24-fold compared to that of control. Analysis of the fermentation kinetics of G. lucidum suggested that glucose concentration in the coixenolide-added group decreased more quickly as compared to the control group from days 3 to 9 of the fermentation process, and the polysaccharides biosynthesis were promoted at the same culture period. However, the culture pH profile was not affected by the addition of coixenolide. Enzyme activities analysis indicated that coixenolide affected the synthesis level of phosphoglucose isomerase and α-phosphoglucomutase.     

Green Synthesis of Silver Nanoparticles Using Euphorbia wallichii Leaf Extract: Its Antibacterial Action against Citrus Canker Causal Agent and Antioxidant Potential

Biologically synthesized silver nanoparticles are emerging as attractive alternatives to chemical pesticides due to the ease of their synthesis, safety and antimicrobial activities in lower possible concentrations. In the present study, we have synthesized silver nanoparticles (AgNPs) using the aqueous extract of the medicinal plant Euphorbia wallichii and tested them against the plant pathogenic bacterium Xanthomonas axonopodis, the causative agent of citrus canker, via an in vitro experiment. The synthesized silver nanoparticles were characterized by techniques such as UV-Vis spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and transmission electron microscopy. Moreover, the plant species were investigated for phenolics, flavonoids and antioxidant activity. The antioxidant potential of the extract was determined against a DPPH radical. The extract was also evaluated for phenolic compounds using the HPLC technique. The results confirmed the synthesis of centered cubic, spherical-shaped and crystalline nanoparticles by employing standard characterization techniques. A qualitative and quantitative phytochemical analysis revealed the presence of phenolics (41.52 mg GAE/g), flavonoids (14.2 mg QE/g) and other metabolites of medicinal importance. Different concentrations (1000 µg/mL to 15.62 µg/mL—2 fold dilutions) of AgNPs and plant extract (PE) alone, and both in combination (AgNPs-PE), exhibited a differential inhibition of X. axanopodis in a high throughput antibacterial assay. Overall, AgNPs-PE was superior in terms of displaying significant antibacterial activity, followed by AgNPs alone. An appreciable antioxidant potential was recorded as well. The observed antibacterial and antioxidant potential may be attributed to eight phenolic compounds identified in the extract. The Euphorbia wallichii leaf-extract-induced synthesized AgNPs exhibited strong antibacterial activity against X. axanopodis, which could be exploited as effective alternative preparations against citrus canker in planta in a controlled environment. In addition, as a good source of phenolic compounds, the plant could be further exploited for potent antioxidants.     

Isatin Bis-Indole and Bis-Imidazothiazole Hybrids: Synthesis and Antimicrobial Activity

Isatin and its derivatives are important heterocycles found in nature and present in numerous bioactive compounds which possess various biological activities. Moreover, it is an essential building block in organic synthesis. The discovery of novel compounds active against human pathogenic bacteria and fungi is an urgent need, and the isatin may represent the suitable scaffold in the design of biologically relevant antimicrobials. A small library of 18 isatin hybrids was synthetized and evaluated for their antimicrobial potential on three reference strains: S. aureus, E. coli, both important human pathogens infamous for causing community- and hospital-acquired severe systemic infections; and C. albicans, responsible for devastating invasive infections, mainly in immunocompromised individuals. The study highlighted two lead compounds, 6k and 6m, endowed with inhibitory activity against S. aureus at very low concentrations (39.12 and 24.83 µg/mL, respectively).     

Multifaced Assessment of Antioxidant Power,Phytochemical Metabolomics,In-Vitro Biological Potential and In-Silico Studies of Neurada procumbens L.: An Important Medicinal Plant

This work was undertaken to explore the phytochemical composition, antioxidant, and enzyme-inhibiting properties of Neurada procumbens L. extracts/fractions of varying polarity (methanol extract and its fractions including n-hexane, chloroform, n-butanol, and aqueous fractions). A preliminary phytochemical study of all extracts/fractions, HPLC-PDA polyphenolic quantification, and GC-MS analysis of the n-hexane fraction were used to identify the phytochemical makeup. Antioxidant (DPPH), enzyme inhibition (against xanthine oxidase, carbonic anhydrase, and urease enzymes), and antibacterial activities against seven bacterial strains were performed for biological investigation. The GC-MS analysis revealed the tentative identification of 22 distinct phytochemicals in the n-hexane fraction, the majority of which belonged to the phenol, flavonoid, sesquiterpenoid, terpene, fatty acid, sterol, and triterpenoid classes of secondary metabolites. HPLC-PDA analysis quantified syringic acid, 3-OH benzoic acid, t-ferullic acid, naringin, and epicatechin in a significant amount. All of the studied extracts/fractions displayed significant antioxidant capability, with methanol extract exhibiting the highest radical-scavenging activity, as measured by an inhibitory percentage of 81.4 ± 0.7 and an IC₅₀ value of 1.3 ± 0.3. For enzyme inhibition experiments, the n-hexane fraction was shown to be highly potent against xanthine oxidase and urease enzymes, with respective IC₅₀ values of 2.3 ± 0.5 and 1.1 ± 0.4 mg/mL. Similarly, the methanol extract demonstrated the strongest activity against the carbonic anhydrase enzyme, with an IC₅₀ value of 2.2 ± 0.4 mg/mL. Moreover, all the studied extracts/fractions presented moderate antibacterial potential against seven bacterial strains. Molecular docking of the five molecules β-amyrin, campesterol, ergosta-4,6,22-trien-3β-ol, stigmasterol, and caryophyllene revealed the interaction of these ligands with the investigated enzyme (xanthine oxidase). The results of the present study suggested that the N. procumbens plant may be evaluated as a possible source of bioactive compounds with multifunctional therapeutic applications.