Control Efficacy of Salicylic Acid Microcapsules against Postharvest Blue Mold in Apple Fruit

Salicylic acid (SA) is a natural inducer of disease resistance in fruit, but its application in the food industry is limited due to low water solubility. Here, SA was encapsulated in β-cyclodextrin (β-CD) via the host–guest inclusion complexation method, and the efficacy of SA microcapsules (SAM) against blue mold caused by Penicillium expansum in postharvest apple fruit was elucidated. It was observed that SAM was the most effective in inhibiting the mycelial growth of P. expansum in vitro. SAM was also superior to SA for control of blue mold under in vivo conditions. Enzyme activity analysis revealed that both SA and SAM enhanced the activities of superoxide dismutase (SOD) and phenylalanine ammonia lyase (PAL) in apple fruit, whereas SAM led to higher SOD activities than SA. Total phenolic contents in the SAM group were higher than those in the SA group at the early stage of storage. SAM also improved fruit quality by retarding firmness loss and maintaining higher total soluble solids (TSS) contents. These findings indicate that microcapsules can serve as a promising formulation to load SA for increasing P. expansum inhibition activity and improving quality attributes in apple fruit.     

Gamma radiation effects on physico-chemical parameters of apple fruit during commercial post-harvest preservation

The physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Red Delicious apple subjected to γ radiation were evaluated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 300, 600, 900 and 1200 Gy and stored at 1 °C. Apples were evaluated at three month intervals. The results showed that there was a clear link between phenolic content and antioxidant activity, so that dose range of 900 Gy and higher significantly decreased phenolic content and antioxidant activity. The moisture percent of stored apples was more responsive to irradiation (at doses of 900–1200 Gy) than storage time and pathogen. Lesion diameter of pathogen-treated non-irradiated apples was significantly increased after three months. This means that storage at low temperature is not enough to avoid blue mold growth. As dose and storage time increased firmness decreased; also pathogen accelerated softening of stored apples. This study showed conclusively that low irradiation doses (300 and 600 Gy) combined with cold storage is a way to minimize apple quality losses during nine month storage period.     

Chemical Composition Profiling and Antifungal Activity of Saffron Petal Extract

Numerous fungal plant pathogens can infect fresh fruits and vegetables during transit and storage conditions. The resulting infections were mainly controlled by synthetic fungicides, but their application has many drawbacks associated with the threatened environment and human health. Therefore, the use of natural plants with antimicrobial potential could be a promising alternative to overcome the side effects of fungicides. In this regard, this study aimed at evaluating the antifungal activity potential of saffron petal extract (SPE) against three mains important fungal pathogens: Rhizopus stolonifer, Penicillium digitatum and Botritys cinerea, which cause rot decay on the tomato, orange and apple fruits, respectively. In addition, the organic composition of SPE was characterized by attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and its biochemical, and gas chromatography-mass spectrometry (GC-MS) analyses were carried out. The obtained results highlighted an increased inhibition rate of the mycelial growth and spore germination of the three pathogenic fungi with increasing SPE concentrations. The mycelial growth and spore germination were completely inhibited at 10% of the SPE for Rhizopus stolonifer and Penicillium digitatum and at 5% for B. cinerea. Interestingly, the in vivo test showed the complete suppression of Rhizopus rot by the SPE at 10%, and a significant reduction of the severity of grey mold disease (37.19%) and green mold, when applied at 5 and 10%, respectively. The FT-IR spectra showed characteristic peaks and a variety of functional groups, which confirmed that SPE contains phenolic and flavonoid components. In addition, The average value of the total phenolic content, flavonoid content and half-maximal inhibitory concentration (IC₅₀) were 3.09 ± 0.012 mg GAE/g DW, 0.92 ± 0.004 mg QE/g DW and 235.15 ± 2.12 µg/mL, respectively. A volatile analysis showed that the most dominant component in the saffron petal is 2(5H)-Furanone (92.10%). Taken together, it was concluded that SPE could be used as an alternative to antioxidant and antifungal compounds for the control of postharvest diseases in fruits.     

Synthesis and biological evaluation of γ-fluoro-β,γ-unsaturated acids

Several γ-fluoro-β,γ-unsaturated acids, fluorine-containing analogues of N-acyl glycines, were synthesized via Julia-Lythgoe olefination. The antimicrobial activities of these compounds and synthetic intermediates were evaluated. Analogues with an octyl group showed in vitro antifungal activity agaist Penicillium chrysogenum IFO4626.     

Total production of (R)-3,5-bistrifluoromethylphenyl ethanol by asymmetric reduction of 3,5-bis(trifluoromethyl)-acetophenone in the submerged culture of Penicillium expansum isolate

A total of 82 fungal isolates were screened for their ability to reduce 3,5-bis(trifluoromethyl)-acetophenone 1. Penicillium expansum was found to successfully reduce ketone 1 in the submerged culture. A second screening was performed on the active P. expansum strains identified by the first screening. A number of strains of P. expansum were found to produce (R)-3,5-bistrifluoromethylphenyl ethanol 2 with over 99% enantiomeric excess (ee) from ketone 1. The most productive strain was identified as P. expansum EBK-9, and this strain was selected for further experiments. The total production of 2 was carried out by P. expansum EBK-9 in a laboratory-scale bioreactor employing optimized conditions as determined by our experiments. P. expansum EBK-9 gave 2 with ee >99% and 76% yield. On a large scale, a total of 3.35 g/L of 2 was produced from 1 after 56 h.     

Synthesis of some novel pyrazoline‐thiazole hybrids and their antimicrobial activities

A series of novel thiazolyl pyrazolines 7a‐h , 9a‐f , and 11a‐f have been synthesized by the reaction of thioamide derivatives 5a , b with 1‐aryl‐2‐bromoethanones 6a‐d , chloroacetones 8a‐c , and hydrazonoyl chlorides 10a‐c . Additionally, pyrazoles 15a‐c and 20 were prepared starting from enaminone 13 . These newly synthesized compounds were screened for their in vitro antibacterial activity against four bacterial species. Compound 11b showed a moderate activity against Klebsiella pneumoniae. Compounds 7c and 11c revealed a moderate activity against Pseudomonas aeruginosa. In addition, the antifungal activity of the newly synthesized compounds was determined against five fungal strains. Compounds 7e , 7g , and 11e showed a good activity against Aspergillus flavus and Penicillium expansum.     

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.     

The trace analysis of microorganisms in real samples by combination of a filtration microcartridge and capillary isoelectric focusing

Trace analysis of microorganisms in real biological samples needs very sensitive methods for their detection. Most procedures for detecting and quantifying pathogens require a sample preparation step including concentrating microorganisms from large sample volumes with high and reproducible efficiency. Electromigration techniques have great potential to include the preconcentration, separation, and detection of whole cells and therefore they can rapidly indicate the presence of pathogens. The preconcentration and separation of microorganisms from real suspensions utilising a combination of filtration and capillary isoelectric focusing was developed and the possibility for its application to real samples was verified. For our experiments, spores of Monilinia species and of Penicillium expansum were selected as model bioparticles, as they cause major losses in agrosystems. The isoelectric points of the spores of M. laxa, M. fructigena, M. fruticola, and P. expansum were determined and the method was verified using real samples taken directly from infected apples. The coupling of a filtration cartridge with a separation capillary can improve the detection limit of isoelectric focusing with UV detection by at least 4 orders of magnitude. Spores of M. fructigena and of M. laxa in numbers of hundreds of particles per milliliter were detected on a visually noninfected apple surface which was cross-contaminated during handling and storage. The efficiency of preconcentration and a preliminary identification was verified by the phenotyping technique after cultivation of the spores sampled from the apple surface.     

Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries

Incorporating antimicrobial compounds into edible films or coatings provides a novel way to improve the safety and shelf life of ready-to-eat foods. Diverse studies with Quillaja saponaria Mol. (popularly named quillay) extracts have demonstrated their potential as antifungal agents against phytopathogenic fungi. Crosslinking induced by ionizing radiation is an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on milk proteins. However there are few reports about the effects of γ-radiation on plant extracts. The aim of this work was to evaluate the effect of ionizing radiation (0, 5, 10, 15, 20, 25 and 35 kGy) on extracts prepared from in vitro plants of Q. saponaria to be used as antimicrobial agent in irradiated edible coating based on calcium caseinate and whey protein isolated, and also to establish the concentration of Q. saponaria extract to be added as an antifungal agent in the coating. Gamma irradiation since 15 kGy affects negatively the antimicrobial activity and metabolites composition of extract of Q. saponaria by reducing compounds of phenolic nature. Otherwise no effect on saponins profile was observed even at higher doses. It was possible to conclude that the antifungal activity of Q. saponaria extract is mainly related to phenolic compounds content. In addition, our work also shows that to obtain an efficient antifungal protection is necessary to add a minimum concentration of 6% of the extract after the coating irradiation.     

Sensitivity of Botrytis cinerea Isolates Complex to Plant Extracts

New agricultural strategies aim to reduce the use of pesticides due to their damage to the environment and humans, and the caused resistance to pathogens. Therefore, alternative sources of antifungal compounds from plants are under investigation lately. Extracts from plants have a wide composition of chemical compounds which may complicate the development of pathogen resistance. Botrytis cinerea, causing grey mould, is an important horticultural and ornamental pathogen, responsible for the relevant yield and quality losses. B. cinerea isolated from a different plant host may differ in the sensitivity to antifungal substances from plants. Assessing the importance of research covering a wide range of pathogens for the rapid development of biopesticides, this study aims to determine the sensitivity of the B. cinerea isolate complex (10 strains) to plant extracts, describe morphological changes caused by the extract treatment, and detect differences between the sensitivity of different plant host isolates. The results showed the highest sensitivity of the B. cinerea isolates complex to cinnamon extract, and the lowest to laurel extract. In contrast, laurel extract caused the most changes of morphological attributes in the isolates. Five B. cinerea isolates from plant hosts of raspberry, cabbage, apple, bell pepper, and rose were grouped statistically according to their sensitivity to laurel extract. Meanwhile, the bell pepper isolate separated from the isolate complex based on its sensitivity to clove extract, and the strawberry and apple isolates based on their sensitivity to cinnamon extract.     

Antimicrobial activity of newly synthesized thienoquinolizidines derivatives: inspired by natural plant alkaloids

The antimicrobial activity of 16 newly prepared quinolizidines derivatives using bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Proteus sp., Escherichia coli) acid fast bacterium Mycobacterium smegmatis, yeasts (Candida albicans, Candida parapsilosis), and filamentous fungi (Fusarium culmorum, Microsporum gypseum, Aspergillus flavus, Botrytis cinerea, Alternaria alternata) was studied in this paper. The best antibacterial properties were demonstrated by derivatives 11Ba, trans10Bb and 11Bb, and the most sensitive microorganism was found to be the gram-positive bacterium S. epidermidis. The derivative 11Bb showed the best antifungal activity, while C. albicans was resistant to all tested derivatives, and C. parapsilosis was fully inhibited in the presence of the derivative 11Ba and 11Bb. Among the filamentous fungi, only the dermatophyte M. gypseum was partially inhibited. Biofilms represent the most prevalent type of microbial growth in nature and are crucial to the development of clinical infections. Newly synthesized derivatives were also added into the medium throughout the biofilm formation. We have observed a significant decrease of biofilm formation in the presence of quinolizidine derivatives, testifying to their significant antimicrobial activity. It seems that the relationship between antimicrobial activity and the structure is based on the alkaline character due to nitrogen, the saturated basic quinolizidine skeleton, and the position of sulfur in the molecule.     

Ultrasound-Assisted Hydrodistillation of Essential Oil from Celery Seeds (Apium graveolens L.) and Its Biological and Aroma Profiles

The aim of the research was to increase the efficiency of the hydrodistillation process and determine the volatile composition, biological activity, and aroma profile of essential oil from celery seeds (Apium graveolens L.). The essential oil was extracted from the plant material by ultrasonic hydrodistillation with higher efficiency when compared with classical hydrodistillation. The antimicrobial activity was evaluated using the impedimetric method for the bacteria Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and yeast Candida vini as well as moulds Aspergillus niger and Penicillium expansum with minimal inhibitory concentration (MIC) (μL/mL) values: 30, 10, 20, 3, 30, 40, and 40, respectively. The oil possessed very weak 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity with the half maximal inhibitory concentration (IC₅₀) value of 81.6 g/L. Initial studies of the aroma profile indicated that the perception of the fragrance of the oil could be related to the sex of the panellists. According to women, the fragrance of celery seeds oil was intense herb-like. From the men’s point of view, it had a fresh, mossy, and mushroom scent.     

Janoxepin and brevicompanine B: antiplasmodial metabolites from the fungus Aspergillus janus

Two compounds janoxepin (1) and brevicompanine B (2) were isolated from the fungus Aspergillus janus and the structures elucidated by one- and two-dimensional NMR spectroscopic methods and mass spectrometry. Janoxepin is a novel oxepin derivative with a rare d-leucine incorporated. Brevicompanine B has previously only been isolated from Penicillium brevicompactum. Both compounds were tested in antimicrobial assays and found to be active against the malaria parasite Plasmodium falciparum 3D7 (IC₅₀-values of 28 and 35 mg/ml, respectively). However, no activity was observed in antifungal or antibacterial assays.     

Purification and Application of a Lipase from <Emphasis Type="Italic">Penicillium expansum</Emphasis> PED-03

An extracellular lipase was purified from the fermentation broth of Penicillium expansum PED-03 by DEAE-Sepharose chromatography, followed by sephacryl S-200 chromatography. The enzyme was purified 81.8-fold with 19.8% recovery and a specific activity of 85.94 U/mg. The molecular weight of the homogeneous enzyme was about 28 kDa, determined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The enzymatic resolution of racemic ibuprofen was carried out by the lipase from P. expansum PED-03, and the conversion reached 46% with excellent enantioselectivity(E > 200 ), which showed a good application potential in the production of optically pure ibuprofen.     

Synthesis,antimicrobial activity and docking study of some novel 4-(4,4-dimethyl-2,6-dioxocyclohexylidene)methylamino derivatives carrying biologically active sulfonamide moiety

A new series of 4-((4,4-dimethyl-2,6-dioxocyclohexylidene)methylamino)-N-(substituted)benzenesulfonamide 3–17, monosubstituted 2-((4-((4-aminophenyl)sulfonyl)phenyl)amino)methylene 18, and its disubstituted derivative 19 were synthesized from the starting material 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione 2. The crystal structures of compounds 2, 7 and 13 were reported by us through X-ray crystallography. All the prepared compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Clostridium sporogenes), Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), and antifungal activity against Aspergillus fumigatus, Penicillium chrysogenum, Fusarium oxysporum, Candida albicans. The synthesized compounds displayed interesting antimicrobial activity. Compounds 4 and 12 were the most potent in this study and displayed higher activity compared to the reference drugs, with MIC value of 3.9–31.3 μg/mL against a panel of Gram-positive, Gram-negative bacteria and fungi. Molecular modeling was performed inside the active site of dihydropteroate synthase. The synthesized compounds showed similar orientation and binding interactions to that of the co-crystallized ligand inside the binding pocket.     

A Novel Antifungal Protein with Lysozyme-Like Activity from Seeds of Clitoria ternatea

An antifungal protein with a molecular mass of 14.3 kDa was isolated from the seeds of butterfly pea (Clitoria ternatea) and designated as Ct protein. The antifungal protein was purified using different methods including ammonium sulphate precipitation, ion exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-50 column. Ct protein formed a single colourless rod-shaped crystal by hanging drop method after 7 days of sample loading. The protein showed lytic activity against Micrococcus luteus and broad-spectrum, fungicidal activity, particularly against the most clinically relevant yeasts, such as Cryptococcus neoformans, Cryptococcus albidus, Cryptococcus laurentii, Candida albicans and Candida parapsilosis. It also exerted an inhibitory activity on mycelial growth in several mould species including Curvularia sp., Alternaria sp., Cladosporium sp., Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Rhizopus sp., and Sclerotium sp. The present study adds to the literature on novel seed proteins with antifungal activity.     

In Vitro Antimicrobial Activity of Lavender,Mint, and Rosemary Essential Oils and the Effect of Their Vapours on Growth of Penicillium spp. in a Bread Model System

The chemical composition, antioxidant activity, and antimicrobial properties of three commercially available essential oils: rosemary (REO), lavender (LEO), and mint (MEO), were determined in the current study. Our data revealed that the major components of REO, MEO, and LEO were 1,8-cineole (40.4%), menthol (40.1%), and linalool acetate (35.0%), respectively. The highest DPPH radical-scavenging activity was identified in MEO (36.85 ± 0.49%) among the investigated EOs. Regarding antimicrobial activities, we found that LEO had the strongest inhibitory efficiencies against the growth of Pseudomonas aeruginosa and Candida (C.) tropicalis, MEO against Salmonella (S.) enterica, and REO against Staphylococcus (S.) aureus. The strongest antifungal activity was displayed by mint EO, which totally inhibited the growth of Penicillium (P.) expansum and P. crustosum in all concentrations; the growth of P. citrinum was completely suppressed only by the lowest MEO concentration. The lowest minimal inhibitory concentrations (MICs) against S. enterica, S. aureus, and C. krusei were assessed for MEO. In situ analysis on the bread model showed that 125 µL/L of REO exhibited the lowest mycelial growth inhibition (MGI) of P. citrinum, and 500 µL/L of MEO caused the highest MGI of P. crustosum. Our results allow us to make conclusion that the analysed EOs have promising potential for use as innovative agents in the storage of bakery products in order to extend their shelf-life.     

Novel Galactopyranoside Esters: Synthesis,Mechanism, In Vitro Antimicrobial Evaluation and Molecular Docking Studies

One-step direct unimolar valeroylation of methyl α-D-galactopyranoside (MDG) mainly furnished the corresponding 6-O-valeroate. However, DMAP catalyzed a similar reaction that produced 2,6-di-O-valeroate and 6-O-valeroate, with the reactivity sequence as 6-OH > 2-OH > 3-OH,4-OH. To obtain novel antimicrobial agents, 6-O- and 2,6-di-O-valeroate were converted into several 2,3,4-tri-O- and 3,4-di-O-acyl esters, respectively, with other acylating agents in good yields. The PASS activity spectra along with in vitro antimicrobial evaluation clearly indicated that these MDG esters had better antifungal activities than antibacterial agents. To rationalize higher antifungal potentiality, molecular docking was conducted with sterol 14α-demethylase (PDB ID: 4UYL, Aspergillus fumigatus), which clearly supported the in vitro antifungal results. In particular, MDG ester 7–12 showed higher binding energy than the antifungal drug, fluconazole. Additionally, these compounds were found to have more promising binding energy with the SARS-CoV-2 main protease (6LU7) than tetracycline, fluconazole, and native inhibitor N3. Detailed investigation of Ki values, absorption, distribution, metabolism, excretion, and toxicity (ADMET), and the drug-likeness profile indicated that most of these compounds satisfy the drug-likeness evaluation, bioavailability, and safety tests, and hence, these synthetic novel MDG esters could be new antifungal and antiviral drugs.     

Synthesis and Bioactivity Evaluation of New 6-Aryl-5-cyano Thiouracils as Potential Antimicrobial and Anticancer Agents

Several novel 6-aryl-5-cyano thiouracil derivatives were synthesized and explored for their activities as antibacterial, antifungal and anticancer agents. The antimicrobial evaluation revealed that compounds 7b and 7c possessed superior antibacterial activity against the Gram positive bacteria S. aureus and B. subtilis compared to the reference drug amoxicillin. Moreover, compound 4i was found to be a broad spectrum antimicrobial agent and it also exhibited the highest antifungal activity against C. albicans, even higher than the reference drug amphotericin B (MIC = 2.34, 3.00 μg/mL respectively). Selected compounds were tested for in vitro cytotoxicity at a single 10^-5 M concentration in accordance to the NCI (USA) protocol. The preliminary screening results showed that most of the compounds had limited cytotoxic activity against renal cancer UO-31 and/or A498 cell lines. Nevertheless, compounds 6d and 6i displayed potent growth inhibitory effect toward non-small cell lung cancer HOP-92 and leukemia MOLT-4 cell lines, respectively.     

New phenylpyridone derivatives from the Penicillium sumatrense GZWMJZ-313, a fungal endophyte of Garcinia multiflora

Citridones E-G (1-3), three new phenylpyridone derivatives together with two known curvularins (4 and 5) were isolated from the solid culture of the endophytic fungus Penicillium sumatrense GZWMJZ-313 in Garcinia multiflora. The structures of new compounds were determined in the light of spectroscopic data,X-ray and ECD calculation. Compounds 1 and 3 are racemates, while compound 2 is optically pure.Compounds 1 and 4 showed antibacterial and antifungal activities against Staphylococcus aureus,Pseudomonas aeruginosa, Clostridium perfringens, Escherichia coli and Candida albicans with MIC values ranging from 8 μg/mL to 64 μg/mL.