Antimicrobial Extracts Research Articles

MELICA UNIFLORA YAPRAKLARININ ETANOLİK ÖZÜTLERİNİN IN VITRO BİYOLOJİK AKTİVİTESİNİN DEĞERLENDİRİLMESİ

Melica uniflora is part of the omnivore and herbivore animal diets and there is not enough study about this plant. The aim of the study is to provide the antimicrobial and antioxidant potential of ethanol extract of M. uniflora leaves. Total phenolic and flavonoid contents and antioxidant potential based on different methods and antimicrobial activity of M. uniflora leaves ethanol extract were examined. Disk diffusion method against to eight bacteria strains, the Folin-Ciocalteu method, DPPH free radical scavenging activity and ferric reducing antioxidant power assays were used. Mean diameters of inhibition zones were found in the range of 14.93 mm to 26.32 mm. The total phenolic content of ethanol extract of M. uniflora leaves was determined as 0.466 mg GAE/g. Total antioxidant activity value of the extract was calculated 4.54 mg AAE/g. IC50 value was calculated 18.798 mg/mL for DPPH free radical scavenging activity. The FRAP value indicated that the reducing power of 1 gram of sample was equivalent to 3.33 µmol of trolox. The flavonoid content of the extract was calculated as 4.44 mgQE/g. According to the obtained results, the analyzed M. uniflora leaves ethanol extracts demonstrated antioxidant and antimicrobial activity level can be considered effective.

Application of Natural Neutrophil Products for Stimulation of Monocyte-Derived Macrophages Obtained before and after Osteochondral or Bone Injury.

We evaluated the use of some neutrophil products, namely; autologous rabbit antimicrobial neutrophil extract (rANE), heterologous porcine antimicrobial neutrophil extract (pANE), neutrophil degranulation products (DGP) and neutrophil microvesicles (MVs) for stimulation of monocyte-derived macrophages (MDMs) to improve healing. Two animal models were evaluated; the rabbit model for autologous osteochondral transplantation (OT) with application of rabbit ANE, DGP or MVs for MDMs stimulation, and the ovine model of the insertion of a Ti implant with the use of porcine ANE, and ovine DGP or MVs for MDMs stimulation. Macrophage activity was assessed on the basis of free radical generation and arginase activity. We estimated that DGP acted in a pro-inflammatory way both on rabbit and ovine MDMs. On the other hand, MVs acted as anti-inflammatory stimulator on MDMs in both experiments. The response to ANE depended on origin of extract (autologous or heterologous). Macrophages from rabbits before and after OT stimulated with autologous extract generated lower amount of NO and superoxide, especially after transplantation. In the ovine model of Ti implant insertion, heterologous ANE evoked increased macrophage pro-inflammatory activity. Our study revealed that these neutrophil products could regulate activity of macrophages, polarizing them into pro-or anti-inflammatory phenotypes that could enhance bone and osteochondral tissue healing.

Optimization of Vacuum-Microwave-Assisted Extraction of Natural Polyphenols and Flavonoids from Raw Solid Waste of the Orange Juice Producing Industry at Industrial Scale.

Orange pomace (OP) is a solid waste produced in bulk as a byproduct of the orange juice industry and accounts for approximately 50% of the quantity of the fruits processed into juice. In numerous literature references there is information about diverse uses of orange pomace for the production of high-added-value products including production of natural antioxidant and antimicrobial extracts rich in polyphenols and flavonoids which can substitute the hazardous chemical antioxidants/antimicrobials used in agro-food and cosmetics sectors. In this work and for the first time, according to our knowledge, the eco-friendly aqueous vacuum microwave assisted extraction of orange pomace was investigated and optimized at real industrial scale in order to produce aqueous antioxidant/antimicrobial extracts. A Response Surface Optimization methodology with a multipoint historical data experimental design was employed to obtain the optimal values of the process parameters in order to achieve the maximum rates of extraction of OP total polyphenols and/or total flavonoids for economically optimum production at industrial scale. The three factors used for the optimization were: (a) microwave power (b) water to raw pomace ratio and (c) extraction time. Moreover, the effectiveness and statistical soundness of the derived cubic polynomial predictive models were verified by ANOVA.

Antimicrobial finish on fabrics using phytoconstituents: A review

The use of plant-based natural colorants and some other bioactive natural extracts in textile coatings as antimicrobial textile finishes is gaining traction. Several plant-derived natural colors have potent antibacterial effects. As a result, coating cotton textiles with antimicrobial plant natural dyes and bioactive plant extracts is a new technique in the manufacture of medical cloths. According to current research, depending on the kind of components contained in the plant extract, many plant extracts may be effective against several gram positive and gram negative bacteria. As a result, research on environmentally friendly antimicrobial compounds based on natural ingredients for use in textiles is gaining traction throughout the globe. This article presents a thorough overview of natural product-based bioactive agents for antimicrobial finishing of textile substrates, including chitosan, natural dyes, neem extract, and other herbal items. The mechanism of antibacterial activity of several types of active components identified in extracts of natural products has been described. The goal of this article is to provide the most up-to-date scientific information on the extraction and use of natural colorants in textile processing. The advantages and disadvantages of using natural colorants on textiles, as well as various techniques of extracting natural colorants, have all been addressed.

Screening of Actinomycetes from Soil for Antibacterial Activity

Actinomycetes are Gram positive, free living saprophytes which are distributed in soil as one of the major populations and are primary source of antibiotics. This study was carried out with a quest to isolate actinomycetes from soil samples of different places and assess their antibacterial activity. Isolation of actinomycetes was carried out by serial dilution of soil sample followed by spread plate method. The antimicrobial extract was extracted using ethyl acetate. Assessment of antimicrobial activity was performed by using Agar cup plate assay against test organisms (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Salmonella paratyphi, Bacillus subtilis, Staphylococcus aureus). Antibacterial activity was tested against Methicillin Sensitive Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus in the isolates having effective inhibitory activity against Staphylococcus aureus. From 15 soil samples of 12 different locations, 121 actinomycetes isolates were isolated. Among them, 58 (47.9%) isolates were inhibitory against at least 1 test organism in primary screening, of which 22 isolates effective against more than 1 test organism was chosen for secondary screening. Out of them, 8 were inhibitory against 2 test organisms while 14 were inhibitory against 3 test organisms. Staphylococcus aureus was found to be the most susceptible test organism with its susceptibility against 12 actinomycetes isolates. Among 12 isolates effective against Staphylococcus aureus, 10 were found to have an inhibitory effect against Methicillin Susceptible Staphylococcus aureus while 6 were found to have inhibitory effect against Methicillin Resistant Staphylococcus aureus strain. The findings of this study highlight the inhibitory potential of actinomycetes and the need for further investigation for obtaining novel antimicrobial agents from actinomycetes from various unexplored areas.

Improving the storage stability of tomato paste by the addition of encapsulated olive leaf phenolics and experimental growth modeling of A. flavus

It is necessary to apply some preservatives for tomato paste since in the harvest season, a high load of tomatoes need to be processed as they are among highly perishable products. Application of antimicrobial extracts or essential oils, as natural preservatives, in their raw forms might reduce their efficiency when they are exposed to environmental conditions. However, microencapsulation is a well-known method to solve this problem. Our main goal was to restrict fungal growth rate in stored tomato paste and increase its storage stability by incorporating encapsulated olive leaf phenolic-rich extract. Total Soluble Solids (TSS), consistency, pH, color indices and diametrical growth rate of Aspergillus flavus were measured for different samples. The treatments designed in terms of considering two levels of non-encapsulated olive phenolics extract with 500 and 1000 ppm (NE500 and NE1000), the same levels with encapsulated extract; i.e., 500 and 1000 ppm (ME500 and ME1000), and similar levels of the common preservative of sodium benzoate with 500 and 1000 ppm (B500 and B1000). Antifungal properties of NE samples were higher than ME ones during storage although ME samples could maintain diametrical growth rate of the fungus more stable than NE ones. NE samples justified lower maximum growth rate than ME samples while ME samples could extend lag phase of microbial growth compared with NE one and delay their internal deteriorative reactions. Among Baranyi, modified Baranyi, Modified Gompertz, and Logistic models, Modified Gompertz model represented the best model and could fit the growth factors of A. flavus on tomato paste with higher R2 index as well as lower RMSE and SSE indices. Based on the results obtained, it could be concluded that usage of encapsulated olive leaf extract in tomato paste is an effective, natural and sustainable approach to improve the shelf life of tomato paste since this natural compound could perform as favourable as preservatives; also it could maintain physicochemical as well as microbial properties of tomato paste for a long term. Thus, it is strongly recommended that application of encapsulated olive leaf extract to be considered seriously by the tomato paste industry as it can effectively reduce the mold and fungal contaminations which are very common and prevalent in the plants. The future work in this regard should focus on sensory evaluations when incorporating encapsulated olive leaf extract into tomato paste.

A comparative evaluation of Juniperus species with antimicrobial magistrals.

The objective of this study was to evaluate the in vitro bioactivity of the active ingredient in selected antimicrobial magistral drug formulations and plant extracts used in folk medicine, comparatively. The active ingredients of magistrals such as; boric acid, balsam of Peru, zinc oxide, Calendula tincture, thymol, resorcinol, crystal violet were used as well as fruit or leaf extracts of Juniperus excelsa (Je), J. sabina (Js), J. foetidissima (Jf), J. communis ssp. nana (Jcsn), and J. oxycedrus spp. oxycedrus ripe (Joso) to determine the antimicrobial activity against gram positive bacteria (S. pyogenes, S. aureus, S. epidermidis, E. faecalis), gram negative bacteria (K. pneumoniae, H. influenza, P. aeruginosa, A. baumannii, E. coli), and fungi (Candida. albicans, C. tropicalis, C. parapsilosis, C. krusei) by using microdilution method. The inhibition end point of the minimum inhibition concentrations (MICs) were determined as μ mL-1. The active ingredient and plant extracts have shown antibacterial and antifungal activities with a MIC values of 1->128μmL-1. The active ingredient crystal violet (MIC; 1 μ mL-1) as well as Je- fruit ethanol, Jf-leaf and fruit ethanol, Joso-leaf and fruit ethanol extracts (MIC; 16μ mL-1) have exhibited the highest antimicrobial activities (MIC; 16μ mL-1). Although ingredients of magistrals seem to exert similar antifungal activity against C. albicans, C. tropicalis, and C. parapsilosis (MIC; 32μmL-1), thymol and resorcinol were observed to be more active against C. krusei (MIC; 16μ mL-1). Extracts were more pronounced against P. aeruginosa, A. baumannii, and S. epidermidis (MIC ranging from 16 to 32). In the mine time, the extracts showed equal antifungal activity against C. albicans and C. parapsilosis (MIC; 16μ mL-1). In our study, antimicrobial activity of the natural compounds and ingredients of selected magistrals have found to be promising with MIC values of 16-32μ mL-1. According to the results of our antimicrobial activity studies, utilization of Juniperus extracts in antimicrobial magistral formulations can be suggested.

Phenolic compounds of Tagetes lucida Cav. with antibacterial effect due to membrane damage

Tagetes lucida Cav. (Asteraceae=Compositae) is used for treating stomach infections. The study focused on evaluating the composition and antimicrobial effect of an extract of T. lucida Cav. The plant extracted with ethanol at 10% w/v, and the extract composition analyzed by Rp-HPLC-MS. The antibacterial effect was evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella choleraesuis using disk diffusion, microdilution and bioautography methods. The sytox and comet assays were used to evaluate the mechanism of action. In this way, nine phenolic compounds were detected in the extract of T. lucida. The extract exhibited activity only on S. aureus (MIC of 4.000 mg/ml). The bioautography revealed that the phenolic compounds could act synergistically. The sytox and comet tests showed an antibacterial action of the extract on the bacterial membrane and DNA of this bacterial strain.

Antimicrobial Secretions of Toads (Anura, Bufonidae): Bioactive Extracts and Isolated Compounds against Human Pathogens.

Species of the family Bufonidae, better known as true toads, are widespread and produce bioactive substances in the secretions obtained from specialized skin macroglands. Some true toads have been employed as a folk remedy to treat infectious diseases caused by microbial pathogens. Recent publications based on in silico analysis highlighted the Bufonidae as promising sources of antimicrobial peptides. A review of the literature reveals that Bufonidae skin secretion extracts show inhibitory activity in vitro against clinical isolates of bacteria, resistant and standard strains of bacterial, and fungal and parasitic human pathogens. Secondary metabolites belonging to the classes of alkaloids, bufadienolides, and peptides with antimicrobial activity have been isolated from species of the genera Bufo, Bufotes, Duttaphrynus, and Rhinella. Additionally, some antimicrobial extracts and purified compounds display low cytotoxicity against mammal cells.

Novel Biodegradable Starch Film for Food Packaging with Antimicrobial Chicory Root Extract and Phytic Acid as a Cross-Linking Agent.

The aim of the study was to obtain and evaluate the properties of biodegradable starch film with the addition of phytic acid (0.05%) as a cross-linking agent and chicory root extract (1–5%) as an antimicrobial agent. To prepare biodegradable film, extracts from chicory root obtained with water or methanol were used. The content of bioactive compounds (sesquiterpene lactones and total polyphenols) was evaluated in chicory extracts. The antibacterial activity of the extracts was tested against Gram-negative bacteria (Pseudomonas fluorescens, Escherichia coli) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) using the microculture method. The extracts acted as bacteriostatic agents, decreasing the growth rate (µmax), and extending the lag phase (tlag). The most sensitive bacterium in terms of film bacteriostatic activity was P. fluorescens; all extracts, irrespective of the solvent used, decreased its µmax value. S. aureus was the least sensitive. The obtained films were tested for their properties as food packaging (color, thickness, permeability, mechanical strength). Phytic acid improved the tensile strength and barrier properties of the films. The antimicrobial activity of the films was studied by the disk diffusion method against Gram-negative (P. fluorescens, E. coli) and Gram-positive (B. subtilis, S. aureus) bacteria, as well as fungi (Candida albicans, Aspergillus niger). The growth-inhibiting activity of each obtained film was observed for all tested microorganisms, and the most beneficial effect was observed for films with the 5% level of added extracts obtained with water. The growth-inhibiting activity for fungi, in particular for the yeast C. albicans, was low.

Value-added switchgrass extractives for reduction of Escherichia coli O157:H7 and Salmonella Typhimurium populations on Formica coupons

Recurring outbreaks linked to Escherichia coli O157:H7-contaminated lettuce and Salmonella enterica-contaminated sprouts highlight the need for improved food safety measures. The aim of this study was to determine the ability of a bio-based antimicrobial extract prepared from switchgrass, a dedicated energy crop, to reduce E. coli O157:H7 and S. Typhimurium populations on Formica coupons, a model food-contact surface. Overnight cultures of ~7 log CFU/mL E. coli O157:H7 and S. Typhimurium, air-dried on Formica coupons were treated with 0.625% NaClO, 70% ethanol, sterile water or different batches of switchgrass extractives (SE1, SE2, and SE3) for up to 30 min. E. coli O157:H7 was reduced by 4.43 log CFU/mL after 1 min by SE3, and to non-detectable levels after 1 min by all other treatments. Populations of S. Typhimurium LT2 (15-min drying) were reduced by 3.30 log CFU/mL with 70% ethanol, 5.38 log CFU/mL with SE1, and to non-detectable levels with 0.625% NaClO after 1 min, while S. Typhimurium ATCC 23564 (1-h drying) was non-detectable after 1 min by all treatments. Under soiled conditions, 10-min treatment with SE1 and 70% ethanol reduced both bacteria to non-detectable levels. Studies with concentrated switchgrass extractives combined with various other natural disinfectants or in hurdle approaches warrant further investigation.

Bacterial efflux inhibitors are widely distributed in land plants

Ethnopharmacological relevanceSecondary metabolites play a critical role in plant defense against disease and are of great importance to ethnomedicine. Bacterial efflux pumps are active transport proteins that bacterial cells use to protect themselves against multiple toxic compounds, including many antimicrobials. Efflux pump inhibitors from plants can block these efflux pumps, increasing the potency of antimicrobial compounds. This study demonstrates that efflux pump inhibition against the Gram-positive bacterial pathogen Staphylococcus aureus is widespread in extracts prepared from individual species throughout the land plant lineage. It therefore suggests a general mechanism by which plants used by indigenous species may be effective as a topical treatment for some bacterial infections. Aim of the studyThe goal of this research was to evaluate the distribution of efflux pump inhibitors in nine plant extracts with an ethnobotanical use suggestive of an antimicrobial function for the presence of efflux pump inhibitory activity against Staphylococcus aureus. Materials and methodsPlants were collected, dried, extracted, and vouchers submitted to the Herbarium of the University of North Carolina Chapel Hill (NCU). The extracts were analyzed by quantitative mass spectrometry (UPLC-MS) to determine the presence and concentration of flavonoids with known efflux pump inhibitory activity. A mass spectrometry-based assay was employed to measure efflux pump inhibition for all extracts against Staphylococcus aureus. The assay relies on UPLC-MS measurement of changes in ethidium concentration in the spent culture broth when extracts are incubated with bacteria. ResultsEight of these nine plant extracts inhibited toxic compound efflux at concentrations below the MIC (minimum inhibitory concentration) value for the same extract. The most active extracts were those prepared from Osmunda claytoniana L. and Pinus strobes L., which both demonstrated IC50 values for efflux inhibition of 19 ppm. ConclusionsOur findings indicate that efflux pump inhibitors active against Staphylococcus aureus are common in land plants. By extension, this activity is likely to be important in many plant-derived antimicrobial extracts, including those used in traditional medicine, and evaluation of efflux pump inhibition may often be valuable when studying natural product efficacy.

Screening Fungal Endophytes Derived from Under-Explored Egyptian Marine Habitats for Antimicrobial and Antioxidant Properties in Factionalised Textiles.

Marine endophytic fungi from under-explored locations are a promising source for the discovery of new bioactivities. Different endophytic fungi were isolated from plants and marine organisms collected from Wadi El-Natrun saline lakes and the Red Sea near Hurghada, Egypt. The isolated strains were grown on three different media, and their ethyl acetate crude extracts were evaluated for their antimicrobial activity against a panel of pathogenic bacteria and fungi as well as their antioxidant properties. Results showed that most of the 32 fungal isolates initially obtained possessed antimicrobial and antioxidant activities. The most potent antimicrobial extracts were applied to three different cellulose containing fabrics to add new multifunctional properties such as ultraviolet protection and antimicrobial functionality. For textile safety, the toxicity profile of the selected fungal extract was evaluated on human fibroblasts. The 21 strains displaying bioactivity were identified on molecular basis and selected for chemical screening and dereplication, which was carried out by analysis of the MS/MS data using the Global Natural Products Social Molecular Networking (GNPS) platform. The obtained molecular network revealed molecular families of compounds commonly produced by fungal strains, and in combination with manual dereplication, further previously reported metabolites were identified as well as potentially new derivatives.

Purification, De Novo Characterization and Antibacterial Properties of a Novel, Narrow-Spectrum Bacteriostatic Tripeptide from Geotrichum candidum OMON-1

Antibiotic resistance and need for novel antibiotics have seen focus on antimicrobial peptides (AMPs) increase in recent years. The study investigated purification and de novo characterization of an AMP compound produced by bioactive Geotrichum candidum OMON-1. Antimicrobial extract of G. candidum OMON-1 was purified via reverse-phase high-performance liquid chromatography (RP-HPLC). Purified compound (GP-2B) was characterized on liquid chromatography–mass spectrometry (LC–MS) and MALDI-TOF tandem mass spectrometry (MS/MS), and spectra were interpreted using de novo peptide sequencing protocols. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of GP-2B were determined in vitro against Gram-positive clinical isolates and time-kill kinetics against Staphylococcus aureus investigated, while antimicrobial activity was also observed on scanning electron microscope (SEM). GP-2B was successfully purified on RP-HPLC with trifluoroacetic acid-buffered acetonitrile. LC–MS confirmed GP-2B as pure and positively charged with molecular mass 409.23 amu, while characterization of MS/MS spectrum via de novo peptide sequencing described it a tripeptide with carboxymethylcystyl–asparagyl–aspartate amino acid sequence. GP-2B had MIC 8 and 32 µg/mL against antibiotic-sensitive and -resistant S. aureus, respectively, and 64 µg/mL for Enterococci strains. MBC was fourfold MIC, while GP-2B reduced S. aureus by 21.8% and 30% at 5× and 10× MIC, respectively, in time-kill kinetics. SEM images also confirmed bacteriostasis of S. aureus cells. This study successfully purified and characterized via de novo sequencing, a novel bacteriostatic AMP from G. candidum OMON-1.

Antioxidant and antimicrobial extracts obtained from agricultural by-products: Strategies for a sustainable recovery and future perspectives

Durum wheat and rice brans are by-products deriving from the milling industry and source of important phytochemicals, mostly phenolics in bound form. The objectives of this work were to evaluate the most effective method for the extraction of phenolic acids from these by-products with antioxidant and antimicrobial activity and to standardize the obtained extracts to encourage their commercialization in health field. Free phenolics were extracted with ultrasound-assisted extraction (UAE) and bound phenolics with alkaline hydrolysis (AH) and ultrasound-assisted alkaline hydrolysis (UAAH). Extracts were analyzed with HPTLC (high-performance thin-layer chromatography) and RPHPLC-DAD-ESIMS (reversed-phase high-performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry); the content of trans-ferulic acid, p-coumaric acid, total phenolics were also quantified. The antioxidant activity was investigated using DPPH and ABTS methods. The antimicrobial activity was evaluated against Staphylococcus aureus and Staphylococcus epidermidis strains. Results obtained using UAAH showed the most interesting data, suggesting this method as the most effective to obtain active extracts from the by-products. Durum wheat, extracted with UAAH, exhibited the highest content of trans-ferulic acid (406.14 ± 0.65 μg FA/mg extract), total phenolics (610.58 ± 57.60 mg GAE/g dried extract) and good antioxidant and antimicrobial activities and it has been selected to formulate oil-in-water cosmetic products.

Edible Seaweeds and Spirulina Extracts for Food Application: In Vitro and In Situ Evaluation of Antimicrobial Activity towards Foodborne Pathogenic Bacteria.

Research is more and more focused on studying and selecting food preservatives of natural origin. In this scenario, algae are an excellent source of bioactive compounds, among which are antimicrobials, whose presence is variable depending on the algal species and environmental conditions. The aim of the present study was to obtain, by a food grade approach, antimicrobial extracts from five species already approved as foods and to test their efficacy in vitro (agar well diffusion assay) and in situ (microbial challenge test) towards foodborne pathogenic bacteria. Moreover, the total phenolic compounds of the extracts were determined in order to evaluate possible correlations with the antimicrobial activity. Strains belonging to Salmonella spp., Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were considered. Overall, the extracts showed a good antimicrobial activity in vitro towards all the tested microorganisms, especially L. monocytogenes (15 mm of inhibition diameter). The effect of inhibition was monitored during 24, 48 and 120 h showing a good persistence in time. Arthrospira platensis exerted the highest efficacy, further revealed towards L. monocytogenes on salmon tartare as bacteriostatic using 0.45% of the extract and bactericidal using 0.90%. The presence of phenolic compounds could be related to the antimicrobial activity but was not revealed as the main component of this activity. The extract with the highest phenolic content (18.79 ± 1.90 mg GAE/g) was obtained from Himanthalia elongata. The efficacy, confirmed also in a food matrix, might open perspectives for their application as food preservative.

Antimicrobial Chlorinated 3-Phenylpropanoic Acid Derivatives from the Red Sea Marine Actinomycete Streptomyces coelicolor LY001.

The actinomycete strain Streptomyces coelicolor LY001 was purified from the sponge Callyspongia siphonella. Fractionation of the antimicrobial extract of the culture of the actinomycete afforded three new natural chlorinated derivatives of 3-phenylpropanoic acid, 3-(3,5-dichloro-4-hydroxyphenyl)propanoic acid (1), 3-(3,5-dichloro-4-hydroxyphenyl)propanoic acid methyl ester (2), and 3-(3-chloro-4-hydroxyphenyl)propanoic acid (3), together with 3-phenylpropanoic acid (4), E-cinnamic acid (5), and the diketopiperazine alkaloids cyclo(l-Phe-trans-4-OH-l-Pro) (6) and cyclo(l-Phe-cis-4-OH-d-Pro) (7) were isolated. Interpretation of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS) data of 1–7 supported their assignments. Compounds 1–3 are first candidates of the natural chlorinated phenylpropanoic acid derivatives. The production of the chlorinated derivatives of 3-phenylpropionic acid (1–3) by S. coelicolor provides insight into the biosynthetic capabilities of the marine-derived actinomycetes. Compounds 1–3 demonstrated significant and selective activities towards Escherichia. coli and Staphylococcus aureus, while Candida albicans displayed more sensitivity towards compounds 6 and 7, suggesting a selectivity effect of these compounds against C. albicans.

Antibiotic Resistance and Novel Approaches to Fight Against This Global Crisis.

Since penicillin was discovered by Sir Alexander Fleming in 1928, antibiotics have been used in medicine to treat different infections to combat pathogenic microorganisms. Nevertheless, with their increasing and massive use, progress of resistance has become more predominant and many bacteria have developed resistance to multiple classes of antibacterial agents through genetic exchange mechanisms. Consequently, the use of antibiotics is now under threat. Antibiotic resistance poses a worldwide hazard to both human and animal health and it has become an important public health concern in the 21st century. This review aims to survey some mechanisms of antibiotic resistance. Furthermore, some novel approaches like the use of nanoparticle-based antimicrobial drug delivery, fecal microbiota transfer, antimicrobial peptides, antibiotic adjuvants, antisense antimicrobials, phage therapy, antivirulence strategies, host oriented therapy, synthesis of new antimicrobials and extraction of antimicrobials from natural source like plants are identified and discussed in an attempt to combat and fight against bacterial resistance.

Phytochemical analysis, antioxidant and antimicrobial studies of ethanol extract of Coula edulis seed shell

The phytochemical constituents, antioxidant and antimicrobial potential ethanol extract of Coula edulis (C. edulis) were evaluated. The presence of anthraquinones, steroids phenols, alkaloid, flavonoids, saponins, tannins and deoxy-sugar were ascertained to justify the utilization of this plant in the treatment of diseases. The ethanol extract of Coula edules seed shell was also examined for antioxidant activities and against seven different isolates. Phytochemical profile of the ethanol extract of Coula edulis shell revealed the presence of terpenes, cardiac glycosides, monosaccharides and carbohydrates while alkaloids was found to be absent in the extract. The extract of Coula edules seed shell revealed a very strong antioxidant activity when compared to vitamin C and butylated hydroxytoluene. The antimicrobial result showed that at all concentrations of the seed extract, the growths with almost all the microorganisms were inhibited. The results confirmed high level of antioxidant and antimicrobial properties in ethanol extract of C. edulis contain due to the presence of phytochemical constituents in the plant.

Comparative antidandruff efficacy of plant extracts prepared from conventional and supercritical fluid extraction method and chemical profiling using GCMS

ABSTRACT: Background To combat dandruff associated pathogens, supercritical fluid extraction (SFE) can be used as an alternative eco-friendly technique to obtain antimicrobial plant extracts over conventional methods. Objectives The purpose of the study was to compare the yield and antimicrobial potential of extracts obtained by different extraction methods. Methods Extraction was carried out by cold percolation method using ethyl acetate (EA) and SFE using CO2. Antimicrobial activity was studied against dandruff causing microbes; Malassezia furfur, Propionibacterium acne, and Staphylococcus epidermidis by agar well diffusion and micro broth dilution method. Statistical evaluation was done by principal component analysis (PCA). Results The yield was found higher in the ethyl acetate extracts. PCA indicated that among the sixteen extracts, SFE extract of Azadirachta indica leaves was the most influential with the highest F1 score and maximum antimicrobial activity. Cinnamomum zeylanicum SFE extract demonstrated the lowest MIC against P. acne and M. furfur. GC-MS analysis of A. indica extract inferred that ganoderic acid, 13,14-epoxyoleanan-3-ol acetate, henicosanal, 2-heptadecycloxirane were the major phytoconstituents whereas cinnamaldehyde, α- muurolene and caffeic acid were primarily found in cinnamon. Conclusion Bioactive compounds identified in the extracts of A. indica and C. zeylanicum can be used in natural antidandruff products.