Zone Diameter Research Articles

Design, synthesis and biological Evaluation of novel chromones having 3,4-dihydropyrimidin-2(1H)-one core at C-8 in combination with triazoles: New α-glucosidase inhibitors and anti-bacterial agents

The Biginelli reaction synthesizes dihydropyrimidones through a multi-component reaction. A β-ketoester, aldehyde, and urea or thiourea react in the presence of an acid catalyst to form these dihydropyrimidones. 3,4-Dihydropyrimidin-2(1H)-One/Chromone/Triazole hybrids (9a-9l) were synthesized by multiple steps including one pot Biginelli multicomponent reaction depicted in the scheme. An efficient method for the Biginelli reaction of Chromone aldehyde, acetoacetate esters, and urea employed in the presence of ferric chloride is described. In the end, we have successfully synthesized twelve derivatives of 3,4-Dihydropyrimidin-2(1H)-One/Chromone/Triazole hybrids and subjected them to testing for Antibacterial activity and α-glucosidase inhibition activity. Among these derivatives, compound 9g (IC50 = 142.92 nmol) and 9e (144.49 nmol) exhibited significant inhibitory activity in comparison to the positive control acarbose (IC50 = 350.91 nmol). Compound 9g demonstrated the most significant suppression against Escherichia coli and Bacillus cereus, with zone diameters of 8.8 ± 1.35 mm and 9.1 ± 0.23 mm, respectively. Compound 9b displayed a clear area where bacterial growth was inhibited, measuring 7.5 ± 1.25 mm against Klebsiella pneumonia. Compound 9k exhibited a zone of inhibition measuring 8 ± 1.2 mm in radius against Staphylococcus epidermidis. The docking results for the synthesized compounds indicate that compound 9b exhibited the most favorable docking score of −10 kcal/mol, whereas compound 9a had the second-best docking score of −8.7 kcal/mol. Molecular docking was utilized to examine the interactions between the title compounds and α-glucosidase, in order to provide valuable insights. The data obtained revealed significant interactions that contribute to the inhibitory effects of the drugs against α-glucosidase. These compounds exhibit significant potential as attractive initial candidates for the development of new α-glucosidase inhibitors.

Bioactivity and antibacterial effect of star anise biosynthesized silver nanoparticles against Streptococcus mutans: an in vitro study

BackgroundSilver nanoparticles (AgNPs) are receiving a lot of attention as a prospective antibacterial agent for use in caries prevention. The objective of this study was to investigate the bioactivity and antibacterial effect of silver nanoparticles biosynthesized using Star Anise against Streptococcus mutans (S.mutans).MethodsThe bioactive components of the Star Anise were assessed by employing the gas chromatography-mass spectrometry technique. The antibacterial activities of Star Anise Biosynthesized Silver Nanoparticles against S.mutans bacteria were evaluated using Bauer and Kirby’s disc diffusion mechanism and the minimum inhibitory concentration.ResultsSilver nanoparticles biosynthesized using Star Anise revealed high antioxidant activity. AgNPs inhibited S. mutans with a 16 mm inhibition zone diameter and demonstrated an 80 µg/ml minimum inhibitory concentration.ConclusionsBiologically synthesized AgNPs made from aqueous extract of Star anise appear to be a potential and effective bactericidal agent against S.mutans that can be used to prevent dental caries.

The Effect of Salinity Stress on the Antibacterial Activity of SpirulinaPlatensis Algae

Background: The production of secondary metabolites in different strains of microalgae varies and is likely dependent on environmental conditions. Consequently, the production of bioactive substances as secondary metabolites occurs in microalgae to aid their survival in adverse environmental conditions such as salinity stress. Objectives: The purpose of this study is to investigate the antibacterial activity of the methanolic extract of S. platensis algae cultivated under different salinity stresses against Yersinia rukeri, Escherichia coli, Salmonella sp., and Vibrio cholerae. Methods: The broth microdilution method was used to evaluate the growth inhibitory activity of the extracts against Yersinia ruckeri, Salmonella sp., Escherichia coli, and Vibrio cholerae bacteria. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by this method, and the diameter of the inhibition zone was assessed through the well diffusion method. Results: In the treatment with algae extract grown under 3.5 ppt salinity stress, the concentrations of 50 and 25 mg/mL extract showed the largest inhibition zone diameter against Salmonella sp. compared to other bacteria. Under 7 ppt salinity stress, all studied concentrations of algal extract exhibited a higher inhibition zone diameter against V. cholerae compared to other bacteria. The results of comparing different concentrations of algae extract between the two salinity stresses of 3.5 and 7 ppt for each bacterium showed a significant difference (P < 0.05). As salinity increased, the diameter of the inhibition zone also increased for all bacteria. Conclusions: Our results showed an increase in the antibacterial activity of the methanolic extract of Spirulina platensis with higher salinity stress levels. Therefore, cultivating Spirulina algae in salt water can be a cost-effective and suitable method to produce more secondary metabolites for use in the pharmaceutical industry.

Rosa × damascena Herrm. From Azaran region, Kashan: rich in saturated and unsaturated fatty acids with inhibitory effect against Proteus mirabilis

BackgroundOne of the most widely used medicinal plants in Iranian traditional medicine, Rosa × damascena Herrm. (mohammadi flower) that the people of Kashan use as a sedative and to treat nervous diseases and constipation. In this research, the yield, chemical composition and antimicrobial activity of the essential oil of this plant were evaluated for the first time from Azaran region, Kashan.MethodsThe essential oil was extracted by means of hydrodistillation (Clevenger), and its chemical compounds were identified and determined by GC/MS. The antimicrobial activity of the essential oil was determined by the diffusion method in agar, the minimum growth inhibitory concentration (MIC) and the minimum concentration capable of killing bacterial/fungal microorganisms (MBC/MFC).ResultsThe results showed that the yield of essential oil was 0.1586 ± 0.0331% (w/w). Based on the results of the chemical composition analysis of R. x damascena essential oil, 19 different compounds (98.96%) were identified. The dominant and main components of the essential oil were oleic acid (48.08%), palmitic acid (15.44%), stearic acid (10.17%), citronellol (7.37%) and nonadecane (3.70%). Based on the results of diffusion in agar, the highest zone of inhibition against Candida albicans (ATCC 10231) was ~ 9.5 mm. The strongest inhibitory activity of R. x damascena essential oil against Gram-negative Proteus mirabilis (ATCC 43071) was with the diameter of the inhibition zone (~ 9 mm), which was equal to the strength of rifampin (~ 9 mm).ConclusionTherefore, this essential oil is a promising natural option rich in fatty acids, which can be a potential for the production of natural antimicrobials against infectious diseases, especially urinary tract infections.

Antimicrobial Susceptibility Testing to Erythromycin and Azithromycin of Clinical Isolates of Bordetella pertussis Circulating in Russia

Relevance. Antibacterial drugs are widely used to treat and prevent infections of the upper and lower respiratory tract. The large-scale and unjustified use of antimicrobials to treat these infections has led to the emergence of resistance in most pathogens. The aim. To study antimicrobial susceptibility testing to erythromycin and azithromycin of strains of B. pertussis isolated in Russia. Materials & Methods. The research included 165 strains of B. pertussis isolated in January 2014 to June 2020. Antimicrobial susceptibility to erythromycin and azithromycin was determined by disk diffusion method and MIC test (HiMedia Laboratories Pvt. Limited, India). The A2047G mutation in the 23S rRNA gene was detected by PCR and subsequent sequencing. Results. Disk diffusion zone diameters for erythromycin in the studied strains ranged from 25 to 62 mm (median 44 mm) and disk diffusion zone diameters for azithromycin ranged from 22 to 80 mm (median 50 mm). Isolates with growth inhibition of more than 42 mm in diameter after 7 days of incubation were considered as susceptible. Among the studied strains, 57 (34.5%) were resistant to erythromycin and 23 (13.9%) to azithromycin. Then, MIC of erythromycin and MIC of azithromycin, respectively, were determined for these 57 and 23 strains using the MIC test. The comparison group included 79 isolates that were classified as sensitive to erythromycin (n = 31) and azithromycin (n=48) according to the results of the previous study. A MIC value of 0.12 μg/ml was considered as the cut-off for susceptible strains. All isolates were fully susceptible to erythromycin (MIC ≤ 0.01 μg/ml, median MIC 0.001 μg/ml) and azithromycin (MIC ≤ 0.01 μg/ml, median MIC 0.0001 μg/ml). An A-to-G mutation was not found at position 2047 in the 23S rRNA gene in 80 isolates that had a diameter of growth inhibition zone less than 42 mm. Conclusion. This study demonstrates no significant decrease in the susceptibility to erythromycin and azithromycin among B. pertussis strains isolated in Russia in 2014–2020. The studied B. pertussis strains exhibit a homozygous phenotype for macrolide resistance.

Effects of Flour Extract of Leaves of Terminalia catappa (L) on Aeromonas Motile Septicemia in Cyprinus carpio (L) Larvae

This study aimed to evaluate the effectiveness of Terminalia catappa (L) leaf flour extract in controlling Motile Aeromonas Septicemia (MAS) disease caused by A. hydrophila in common carp larvae. The research method used in this study is an experimental method using a complete randomized design (RAL). This research consists of 2 stages; in vitro and in vivo tests using T. catappa leaf extract. In vitro test, T. catappa leaf extract consists of 5 different doses; The treatments consisted of 0 (negative control), 20, 40, 80, and 100 g L-1 T. catappa leaf flour extract and Stroptomycinsulphate 0.005 g (positive control). In vivo test, 3 best doses were selected based on the diameter zone of inhibition; 60, 80, and 100 g L-1, with positive (using Stroptomycinsulphate 0.005 g and untreated sample (without T. catappa leaf flour extract), each with 3 replicates. The results showed that using T. catappa leaf flour extract can significantly increase the fish's immune response, resistance, and survival. Duncan's further test showed that the 100 g L-1 dose treatment revealed an increase in immune response and survival rate compared to the F and G treatments.

Superb ruthenium(ii) complex melody: Uncovering its hidden catalytic and biological properties

Aliphatic/aromatic nitrogen-substituted ligands have a very important role in ruthenium chemistry. Polydentate ligands with N-substituted pyridine rings are notable for their ability to easily modify the electronic and steric properties of ruthenium. In this study, the catalytic and biological activities of the [RuCl2(NNN)(CH3CN)] (NNN: 2,6-di(1H-pyrazol-3-yl)pyridine)) complex were examined for two different applications. Firstly, the superb Ru(II) complex was used to catalyze the methanolysis of NaBH4, and its initial rate was calculated as 69360 mLH2min−1gcat−1. Secondly, the biological activities of the superb Ru(II) complex were examined. Accordingly, it was determined that this homogeneous complex showed anti-microbial activity on all bacteria used in the study, among the Gram-positive bacteria used in the study, the best result belongs to the Bacillus cereus EMC 19 bacterium with 8 mm, while among the Gram-negative bacteria, the best zone diameter belongs to the Pseudomonas aeruginosa DSM 50071 bacterium with 5 mm. However, it was observed that zone diameters varied between 8 mm and 3 mm. Compared to the control group, it was determined that 0.25 mg/mL concentration had 94.87%, 0.5 mg/mL concentration 96.10%, 1 mg/mL concentration 96.50%, and 2 mg/mL concentration 97.09% cytotoxic activity on the SH-SY5Y cell line. it was determined that all doses of the superb Ru(II) complex used in the study showed anti-cancer activity, but the anticancer activity shown at low doses was statistically more significant at the p < 0.05 level.

Chemical profile by GC-MS and protective effect of Algerian cloves (Syzygium aromaticum) against Lactobacillus spp. and Streptococcus spp. isolated from dental caries

The oral cavity is home to a large and diversified microbial flora, which plays an important role in the genesis of multiple diseases, including tooth decay. Indeed, tooth decay is the most common ailment in the world, with almost everyone having experienced it at least once in their lifetime. Examining plants used in traditional medicine is one of the research approaches used to discover novel, potent antibacterial chemicals with a broad spectrum of action, as present antibacterials have significant drawbacks. This study aims to examine the chemical composition of Algerian clove Syzygium aromaticum using GC-MS and to evaluate the antibacterial activity of the methanol extract against bacteria isolated from dental caries caused by Streptococcus spp. and Lactobacillus spp. The results show a strong extraction yield of 29.7%, with high amounts of polyphenols and flavonoids calculated at 178.82 mg GAEQ/g and 24.13 mg QEQ/g. The principal chemical elements of S. aromaticum peel methanol extract were identified as eugenol (61.23%) and eugenol acetate (26.45%) based on mass spectrum data and retention times. The methanol extract has a significant antibacterial effect against tested strains, with MICs ranging from 111.37 to 445.5 mg/mL. Higher concentrations of polyphenols resulted in a significant increase in inhibition zone diameter against S1 (r2 = 0.94, p &amp;lt; 0.001), L3 (r2 = 0.94, p &amp;lt; 0.001), L5 (r2 = 0.93, p &amp;lt; 0.001), and L9 (r2 = 0.96, p &amp;lt; 0.001).

Chemical profiling and bioactivity studies on aerial parts Ammoides atlantica (Coss. et Durieu) H. Wolff

The Algerian endemic plant Ammoides atlantica (Coss. et Durieu) H. Wolff was studied for the chemical profiling and biological activities of its essential oil (EO) and ethanolic extract (EE). The chemical analysis by GC/MS and HPLC/DAD/UV revealed, respectively, the major compounds thymol (39.46%), γ-terpinene (31.74%), and p-cymene (19.01%) in the EO, and apigenin (33.58%), luteolin 7-O-glucoside (20.09%), and luteolin (14.39%) in the EE. The EO exhibited strong antioxidant activity, with a significant ABTS•+ scavenging capacity (IC50 = 2.79 µg/mL) compared to EE, Trolox, and BHT. The EE showed comparable effects to BHT in DPPH scavenging and reducing power tests. Moreover, the EO demonstrated noteworthy antibacterial activity against S. aureus, E. coli, and P. aeruginosa, with inhibition zone diameters ranging from 32.1 to 70 mm and MICs below 0.3 to 5 mg/mL. Furthermore, the EE exhibited strong anti-inflammatory activity by inhibiting hemolysis of red blood cells &amp;gt;70% at a concentration of 20 µg/mL.

Antifungal Activity the Active Fraction of Orange Jasmine (Murraya paniculata (Linn) Jack) Leaves and Stem Bark Against Malassezia furfur

Leaves and stem bark of orange jasmine have bioactive compounds such as phenol and flavonoids, which these compounds could be extracted by organic solvent and have antifungal activity against Malassezia furfur which cause excema, dandruff and tinea versicolor in humans. Fractionation of the extract would obtain a specific compound based on the polarity of the solvent. This research aims to know the active fraction of leaves and stem bark of orange jasmine which had antifungal activity against Malassezia furfur. The simplicia powder of leaves and stem bark orange jasmine was macerated with 96% ethanol solvent and then fractionated as gradually with n-hexane, ethyl acetate, and water solvent. The antifungal activity of ethanol extract and fractions was tested against Malassezia furfur with 80; 90; 100% concentration by disk diffusion method at 37˚C for 48 hours of incubation. The data of antifungal activity was analyzed by two-way ANOVA. The result of this research showed antifungal activity from active fraction as water fraction of leaves and stem bark of orange jasmine against Malassezia furfur. The diameter of inhibition zones for the active fraction of leaves and stem bark of orange jasmine such as 8.6 – 14 mm and 12.3 – 15.8 mm respectively.

Evaluation of antifungal efficacy of albedo extract of Punica granatum on Candida albicans – An in vitro study

Abstract Introduction: The study aims to investigate the antifungal efficacy of albedo extract of Punica grantum on candida albicans by evaluating the inhibitory capacity of alcoholic albedo extracts by disc diffusion method and by comparing the antifungal efficacy of alcoholic extract of albedo with clotrimazole and ethanol. Methods: Using a conventional disc diffusion method, the effectiveness of Punica Granatum albedo extract against Candida albicans was assessed and evaluated depending on the presence or absence of inhibition zones, as well as the average diameter of inhibition zones. Albedo extract of Punica granatum serial dilutions were prepared ranging from 1%, 5%, 10%, 15%, 20% and 25% and its antifungal efficacy was tested against Candida albicans in comparison with clotrimazole and ethanol. Results: When compared to clotrimazole, the albedo extract of punica granatum showed significant anticandidal activity. The mean zone of inhibition of extract was recorded at 27.6 mm whereas clotrimazole was 21.6 mm and no zone of inhibition was recorded for ethanol. Statistically significant p value 0.015 was recorded within the different dilutions of albedo extract of Punica grantum which is less than 0.05. Conclusion: The present investigation found that Punica Granatum albedo extract had greater potent antifungal activity when compared to clotrimazole and ethanol.

Impact of dexmedetomidine as an adjuvant to peribulbar anesthesia on the retinal vasculature in glaucoma patients: an optical coherence tomography angiography study

Objectives To assess Dexmedetomidine’s effect as an adjuvant to peribulbar anesthesia on the retinal vasculature in patients with glaucoma undergoing cataract extraction surgery via optical coherence tomography angiography (OCT-A). Participants Thirty-nine glaucoma participants planned for phacoemulsification were allocated into two groups. A 10 ml mixture of peribulbar anesthesia was administered to group I. This anesthetic mixture consisted of 4.5 ml of lidocaine 2% mixed with 4.5 ml of bupivacaine 0.5%,1 ml of dexmedetomidine (50 µg), and 150 IU hyaluronidase. Group II was administered a peribulbar anesthetic mixture consisting of 4.5 ml of lidocaine 2% combined with 4.5 ml of bupivacaine 0.5%,150 IU of hyaluronidase, and 1 ml of normal saline, totaling 10 ml. Optical coherence tomography angiography was used 10 mi before and 10 min after injection to scan optic disc total vessel density, foveal superficial deep capillary plexuses (DCP) density, radial peripapillary capillary network density, and total vessel density plus foveal avascular zone (FAZ) diameter. We also checked the intraocular pressure (IOP) before and 10 min after the anesthetic injection. Results After the administration of the peribulbar anesthetic, group II demonstrated a notably higher significance in the DCP fovea median percent change (–43.7%) compared with group I (-2%) (P&lt;0.001). Additionally, group II experienced a considerably greater median percent change in DCP total density (–22.4%) postinjection compared to group I (–0.8%) (P value &lt; 0.001). The postinjection median percent changes in foveal total vessel density and superficial vessel density were −16.2% and −56.8% in group II, and −1% and −2.4% in group I, respectively, with a P value less than 0.001. Moreover, following the injection, the median percentage change in the diameter of the foveal avascular zone was significantly higher in group II (–40.6%) than in group I (–2.3%) (P value &lt; 0.001). Additionally, there was a noteworthy increase in the optic disc’s total vessel density and the median percentage shift in radial peripapillary capillary network density in group II (–13.1 and −13.7%, respectively) compared with group I (–1.2 and −1%, respectively, P value &lt; 0.001). IOP before and after injecting the anesthesia was insignificantly different between the studied groups (P =0.198 and 0.069, respectively). Conclusion The addition of dexmedetomidine to the peribulbar anesthesia demonstrates a protective effect on the retinal microvasculature against the ischemic impact of anesthetic drugs with no significant effect on the IOP. This effect holds significant implications for glaucoma patients.

Enhanced antimicrobial potency and stability of juglone/β-cyclodextrin inclusion complexes: a comparative study of formulation methods

Juglone (5-hydroxy-1,4-naphthoquinone), a natural antifungal and antibacterial agent derived from walnut trees, possesses significant therapeutic potential limited by its low water solubility and instability in varying pH and temperature conditions This study aims to address these limitations by enhancing juglone’s solubility, stability, and antimicrobial efficacy through the formation of inclusion complexes with β-cyclodextrin (β-CD). Employing methods such as co-precipitation, freeze-drying, and solvent evaporation, we synthesized these complexes and confirmed their formation using UV–vis, and FT-IR spectroscopy. The obtained optimum complex was characterized using SEM to reveal its structural properties, while NMR analysis showed significant chemical shift changes, indicative of complex formation between juglone and β-CD; additionally, XRD analysis confirmed the amorphous nature of the J-β-CD3-4 inclusion complex, providing direct evidence for its formation. Our findings reveal a notable enhancement in the pH and thermal stability of juglone within the β-CD inclusion complex, in comparison to its free form. Moreover, the antimicrobial activity of the juglone-β-CD complex surpassed that of juglone alone. The increased water solubility of juglone in the inclusion complex contributed to its enhanced antimicrobial activity. The inhibition zone diameters of J-β-CD3-4 inclusion complex against E. coli, S. aureus, and C. albicans were 7, 22, and 8.5 mm, respectively, relatively higher than juglone. Remarkably, in the broth microdluation method, the MIC and MBC values of the inclusion complex were determined to be much lower than those of free juglone, a significant fourfold decrease for S. aureus, and C. albicans and twofold for E. coli. These results underscore the potential of juglone-β-CD complexation in extending the applicability of juglone, especially in sectors such as food preservation, agriculture, and pharmaceuticals, where enhanced stability and efficacy of natural antimicrobial agents are crucial.

Synthesis of Silver Nanoparticles Using Azadirachta indica and Syzygium aromaticum Extract and Its Antibacterial Action Against Enterococcus faecalis: An In Vitro Study.

Introduction Nanotechnology is the study of manipulating matter at the atomic scale involving particles smaller than 100 nm. Silver nanoparticles (AgNPs) are gaining popularity across diverse sectors including medical, food, healthcare, consumer goods, and industrial fields due to their distinctive physical and chemical characteristics. The eco-friendly synthesis of AgNPs offers a straightforward, cost-effective, and environmentally benign method devoid of hazardous chemicals. Methodology Eighty milliliters (mL) of silver nitrate mixed with 20 mL of Azadirachta indica and Syzygium aromaticum plant extract underwent two days of magnetic stirring for AgNP synthesis. Characterization was done via ultraviolet-visible (UV-vis)-spectroscopy (300-700 nm), and antimicrobial properties, which were checked with Enterococcus faecalis, were assessed using the agar-well diffusion method. Results The change in color and peak observed in the UV-vis spectrum confirmed the successful synthesis of AgNPs. Both neem and clove extract-mediated synthesis of AgNPs exhibited antibacterial activity against E. faecalis. However, neem extract synthesized AgNPs displayed a larger inhibitory zone diameter and lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values compared to those synthesized using clove extract. Conclusion Incorporating neem and clove extracts in AgNP synthesis offers a practical, eco-friendly, and cost-efficient method with notable efficacy. These AgNPs exhibit antibacterial activity against E. faecalis, suggesting their viability as potent antibacterial agents for addressing oral pathogens. Their sustainable synthesis underscores a promising avenue for developing effective antimicrobial solutions in oral healthcare.

Salvia fruticosa mill leaves: chemical assessment and antimicrobial activity of different extracts based on molecular docking study

The primary objective of this study is to identify and analyze the lipid and flavonoid components present in Salvia fruticosa Mill, as well as to assess its potential antibacterial activity. Introduction: Salvia fruticosa Mill (SF) is considered a significant medicinal plant that is found all over the world. Method: The essential lipid contents (fatty acids and unsaponifiable matter), the volatile oil from leaves, and the antibacterial activity of various extracts were all evaluated. The lipid components were extracted with n-hexane then fractionated. Four flavonoids, namely luteolin, cosmos, cynaroside, andorientin, were isolated from the alcoholic extract of the plant by chromatographic and spectroscopic methods. The extracts were tested for their antimicrobial activity against various microorganisms by measuring the inhibition zone diameter using disc diffusion method. A molecular docking study was performed to assess the binding affinity of the flavonoids to the DNA gyrase enzyme, which is a crucial target for antibacterial drugs. Caryophyllene (18.70%), lab-13-ene,8,15-diol (15.93%), methyl linoleate (10.53%), and 1,8-cineole (8.24%) are the most prevalent components in the volatile oil, according to the GC/MS analysis. The lipid components were fractionated into three groups: the unsaponifiable fraction, the fatty acid OMe (FAME), and the insoluble fraction of the acetone (fatty alcohols and hydrocarbons). The obtained results show remarkable antifungal activity with chloroform extract against A. flavus and moderate activity against A. niger. Besides, the butanol and ethyl acetate extracts presented high activity against Sarcina sp. with inhibition zone of 22 mm. The microorganism B. cerus was affected moderately by ethyl acetate and chloroform extracts with inhibition zone of 14 and 12 mm, respectively. The methanol extract was active against C. albicans only. The fatty acids fraction inhibited the growth of A. flavus with inhibition zones of 8, 10 and 14 mm for different concentrations, respectively. The Docking results revealed that all compounds exhibited a promising interaction into the DNA-gyrase, which agrees with an experimental data got from the antibacterial activity assay. These results were obtained first for this plant, especially the results of molecular docking study in relation to antibacterial activity.

Isolation, characterization, antimicrobial properties, and theoretical investigations of a new isoflavanol from nigerian red propolis for therapeutic applications

The chemical components of Nigerian red propolis were thoroughly examined to identify its phytochemical constituents. The investigation yielded a new isoflavanol, identified as 2′,7-dihydroxy-3′,4-dimethoxyisoflavan-4-ol (DDI), which was isolated from the ethyl acetate extract. Using advanced spectroscopic techniques, such as 1D, 2D NMR as well as HR-LC-MS, the structure and molecular composition of the new compound was determined with extreme precision. The present study offers important information regarding the chemical structure of reddish propolis sourced from the southeast region of Nigeria. The isolated compound suggests that the botanical source of the propolis could be Dalbergia spp. antimicrobial assay of the compound isolated revealed potent antibacterial and antifungal properties with diameter zones of inhibition measuring between 27 and 32 mm. The MIC, MBC, and MFC values were between 6.25 and 25 µg/mL. Further theoretical investigations of DDI were also carried out using DFT/D3(BJ)-B3LYP/6–311 ++ G (d, p) level of theory, of DDI in different environments (DMSO, Ethanol, Gas, and Water), that demonstrated structural stability of DDI in the different solvents with an energy gap of 7.0878 eV, 7.0831 eV, 6.9335 eV, and 7.0899 eV respectively. Molecular docking was employed substantiating the antimicrobial analysis, resulting in a score for receptors Candida tropicalis (1N9G), Escherichia coli (4LFU), Candida albicans (5K04), and Helicobacter pylori (4HI0) with binding affinity of -6.9 Kcal/mol, -8.5 Kcal/mol, -7.9 Kcal/mol, and -7.7 Kcal/mol respectively, compared with a conventional drug (fluconazole and amoxicillin) the docking proteins receptors. The docking for the DDI ligand against the receptor proteins of the studied organisms showed better inhibitory activity than the conventional drug (fluconazole), however, less activity with amoxicillin suggesting a more antifungal activity than antibacterial activity, presenting DDI ligand as a potential drug molecule against candidiasis.

Effectiveness of Citronella Extract (Cymbopogon nardus) Mouthwash From Microwave-Assisted Extraction Method Against Streptococcus mutans

Cymbopogon nardus, or citronella has a distinctive aroma is known as a source of essential oils. Extract of citronella can be use as mouthwash to reduce bad breath and protect teeth from bacteria that cause dental caries. C. nardus contains antibacterial compounds such as flavonoid, essential oils, polyphenols, and saponin which are also act as antioxidant compounds. This research was carried out to formulate mouthwash using citronella extract and determine the antibacterial activity of the citronella mouthwash against S. mutans bacteria using disc diffusion method. The microwave extraction method (MAE) was used to obtain extract using 70 % and 96 % ethanol as a solvents. The mouthwash were made in 3 formulas i.e. formula 1, formula 2, and formula 3 each contain 25 % w/v, 30 % w/v, and 35 % w/v) respectively. The quality of mouthwash includes organoleptic, pH, viscosity and hedonic was evaluated and antibacterial activity was determined by measuring the value of minimum inhibitory concentration (MIC) and diameter of inhibition zone. The MIC value of citronella extract was achieved at concentration 20 %. All mouthwash formula met the requirements for a good mouthwash. Formula 1 was the most preferred formula by the panelists based on the hedonic test. Formula 3 had the strongest antibacterial activity with diameter inhibitory of 17.6 ± 0.52 mm. It was concluded that citronella mothwash has the potential to be developed into an antibacterial mouthwash.

ANTIBACTERIAL ACTIVITY TEST OF TEA TREE AND LEMON OIL COMBINATION AND ITS FORMULATION IN CREAM PREPARATION

Tea tree oil contains hydrocarbon compounds, namely terpenes, especially monoterpenes, sesquiterpenes, and alcohols. Terpinen-4-ol is the main component of tea tree oil, which has antimicrobial activity. Lemon oil is useful as an antibacterial because it contains flavonoids that prevent attacks from pathogenic bacteria. This study aims to determine whether tea tree and lemon oil have antibacterial activity against Propionibacterium acnes bacteria and can be formulated into cream preparations. The antibacterial activity test of the combination of tea tree oil and lemon oil in the 1: 1, 1: 2, and 2: 1 ratio was carried out in vitro against Propionibacterium acnes bacteria by disc diffusion method and using virile gel as a positive control. The cream stability test is replicated using the cycling test method with organoleptic test parameters, homogeneity, pH, dispersion, cream type testing, viscosity, and flow properties. The stability test results with the cycling test method showed good stability results, including organoleptic tests, homogeneity, spreadability, pH, emulsion type, viscosity, and flow properties. The combination of tea tree and lemon essential oils in a 1:1, 1:2, 2:1 ratio has antibacterial activity against Propionibacterium acnes bacteria with inhibition zones diameter ±1,23 cm, ±1,12 cm, and ±1,12 cm and control has ±1,53 cm. Combining tea tree and lemon essential oil in a 1:1, 1:2, and 2:1 ratio has antibacterial activity against Propionibacterium acnes bacteria and can be formulated into cream preparations. Keywords: tea tree oil, lemon oil, antibacterial, Propionibacterium acnes, cream.

Penentuan Minimum Inhibitory Concentration (MIC) minyak atsiri Acorus calamus terhadap Aspergillus flavus

Balinese lontar manuscripts are documentation of past Balinese culture. The main component of palm leaves is cellulose. Efforts to prevent damage to lontar manuscripts from cellulose-degrading fungi such as Aspergillus flavus are needed to maintain Balinese local wisdom. The purpose of this study was to evaluate the Minimum Inhibitory Concentratiton (MIC) value of jangu leaf essential oil (Acorus calamus) in inhibiting the growth of A. flavus in vitro. The results obtained were the optimum concentration of A. calamus essential oil at 5% (v/v), with an average inhibition zone diameter of 11.72 mm (strong category). Minimum Inhibitory Concentration (MIC) of jangu leaf essential oil in inhibiting A. flavus is 2% v/v with an average inhibition zone diameter of 7.08 mm. This research opens new insights in the conservation of Balinese ancient manuscripts from damage caused by cellulose-degrading fungi, by utilizing the essential oil of local Balinese plants, namely jangu leaf (A. calamus).

Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam

Abstract. Thi QVC, Minh NLK, Thuy NP, Tat TQ, Tran T. 2024. Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam. Biodiversitas 25: 2576-2585. Endophytic bacteria bring many benefits to plants, such as stimulating plant growth and inhibiting many microbial pathogens that cause plant diseases. Hence, this investigation aimed to evaluate the association of endophytic bacteria with wild rice (Oryza rufipogon) that can fix nitrogen, solubilize phosphorus and produce indole-3-acetic acid (IAA). Twelve-five bacterial strains were recovered from wild rice stems and roots collected from Vinh Long and Tien Giang provinces of the Mekong Delta. Among these strains, six had phosphorus solubilizing and seven had nitrogen-fixing activity. Strain BR3.5 fixed the highest nitrogen, i.e. ammonia (NH4+) content of 0.109 ± 0.002 mg/L after eight-day incubation. However, the highest phosphorus solubilization was recorded in two isolates, RR3.7 and RR1.1, with clear zone diameters of 0.800 ± 0.020 mm and 0.800 ± 0.030 mm, respectively. In addition, bacterial strains could synthesize IAA, and BR2.5 produced the highest, i.e., 0.067 ± 0.002 ?g/mL, IAA after eight-day incubation. Notably, strain BR3.5 exhibited multiple activities like nitrogen fixation (0.109 ± 0.002 mg/L), phosphorus solubilization (1.02 ± 0.002 mm), and IAA synthesis (0.056 ± 0.00 ?g/mL). Strain BR3.5 was identified as Pantoea sp. based on 16S rRNA gene sequencing (92.69% similarity) together with morpho-physiological and biochemical characteristics. The findings indicate that strain BR3.5 may be used for the production of biofertilizers for rice farming.