A new isoflavone glucoside and other compounds from Poiretia bahiana C. Mueller: Chemophenetics, fragmentation pattern and biogenetic implications.

The genus Poiretia belongs to the Fabaceae (Leguminosae) family and it encompasses twelve species of flowering plants. The chemistry of this genus is scarcely investigated, although some studies have demonstrated the potential of Poiretia species to produce important bioactive compounds. Herein, we describe the phytochemical investigation of P. bahiana C. Mueller leaves. A new isoflavone glucoside named as 2',4',5'-trimethoxyisoflavone-7-O-ß-D-glucopyranoside (1), along with six known isoflavones (2-7), two rotenones (8-9), cyclitol 3-O-methyl-chiro-inositol (10), the amino acid proline (11), a mixture of sitosterol (12) and stigmasterol (13), and a mixture of the triterpenes lupeol (14) and ß-amirine (15) were obtained from P. bahiana leaves. The structures were established by extensive analysis of their spectroscopic data, which included 1H NMR, 13C NMR, DEPT, and 2D-NMR (13C1H HETCOR and 13C1H COLOC). Two isoflavones (3 and 5) and two rotenones (8-9) exhibited antifungal activity against the plant pathogenic fungus Cladosporium sphaerospermum. Furthermore, the biogenetic implications of the oxygenation pattern of the B-ring of the isoflavones, and the chemophenetics and fragmentation pattern of the isoflavones and rotenones are discussed.

Biocontrol potential of chitinases produced by newly isolated Chitinophaga sp. S167.

A chitinolytic bacterium Chitinophaga sp. S167 producing extracellular chitinases was isolated from a soil sample in India. The extracellular chitinases produced by S167 were concentrated by ammonium sulphate precipitation (AS70) and seven bands corresponding to chitinases were observed by zymography. Optimum temperature and pH of AS70 were between 40 and 45 °C and pH 6.0 respectively with high stability at 20-40 °C and pH 5-7. AS70 inhibited the growth of Fusarium oxysporum, Alternaria alternata and Cladosporium sp. in vitro. The culture conditions for the high level production of extracellular chitinases were optimized resulting in 48-folds higher chitinase production. As the combination of chitinases could be more potent in biocontrol of plant diseases, it was checked if AS70 could control postharvest fungal infection caused by Fusarium oxysporum on tomatoes. AS70 treated tomatoes showed significant lower incidence of infection (11%) by F. oxysporum as compared with 100% in the control at 5 days post inoculation. Further, AS70 caused significant mortality in second stage juveniles of root knot nematode, Meloidogyne incognita, a major agriculture pest responsible for economic losses in agriculture. This study highlights the antifungal and nematicidal activity of chitinases produced by Chitinophaga sp. S167. To the best of our knowledge, this is the first report of the biocontrol potential of the chitinases produced by Chitinophaga sp.

Purification and characterization of salvianolic acid B from Streptomyces sp. M4 possessing antifungal activity against fungal phytopathogens.

The emergence of resistance among fungal phytopathogens poses a biggest threat across the world. Streptomyces are a group of spore-forming Gram + ve bacteria and prolific producers of secondary bioactive metabolites which have been used as biocontrol agents against phytopathogens and also known for plant growth promotion. The current study identified a potent isolate M4 from soil with broad spectrum antifungal activity against different fungal phytopathogens. The isolate was identified as a Streptomyces sp. on the basis of cultural, morphological, physiological, biochemical and phylogenetic characteristics. 16S rRNA gene sequence of M4 showed 100 % similarity with three Streptomyces spp. i.e. Streptomyces plicatus NBRC 13071 T (AB184291), Streptomyces rochei NBRC 12908 T AB184237 and Streptomyces enissocaesilis NRRL-B-16365 T (DQ026641). However, phenotypic and phylogenetic analysis concluded that M4 represents a novel sp. within the genus Streptomyces. One of the two antifungal compounds purified from Streptomyces M4 was identified as salvianolic acid B. To our knowledge, the present study is the first work reporting purification and characterization of salvianolic acid B from Streptomyces and its broad spectrum antifungal activity against different fungal phytopathogens viz. Alternaria spp., Fusarium spp., Colletotrichum spp., Cladosporium herbarum and Botrytis cineria. Salvianolic acid B was found to be photostable, thermostable (up to 70 °C) and non-mutagenic in nature and might be developed as safe biofungicide to control phytopathogens.

Epoxy Coatings Based on Modified Vegetable Oils for Wood Surface Protection against Fungal Degradation.

The study describes the curing and thermal behavior of a new castor oil maleic anhydride adduct/epoxy oils/5-Bromosalicylic acid coatings and their composites with wood. The epoxidized oils were flax and hemp. The kinetic parameters of the curing and thermal degradation processes were calculated. The resistance of the coated wood surfaces against Cladosporium cladosporioides, Aspergillus brasiliensis, and Penicillium chrysogenum was tested. Color changes, FT-IR and SEM were conducted before and after fungal attack. The decay resistance and color change of raw wood and wood treated samples against fungi was tested. Based on the color changes and according to ASTM D 2017, the decay resistance rating for covered samples was considered as "highly resistant". Chemical resistance and coating performance tests were also undertaken. The obtained results recommend the described materials for applications in wood protective coatings.

Assessment of chemically characterised Myristica fragrans essential oil against fungi contaminating stored scented rice and its mode of action as novel aflatoxin inhibitor.

The study reports chemically characterised Myristica fragrans essential oil (MFEO) as plant based food preservative against fungal and aflatoxin B1 (AFB1) contamination of scented rice varieties. The chemical profile of MFEO revealed elemicin (27.08%), myristicine (21.29%) and thujanol (18.55%) as major components. The minimum inhibitory and minimum aflatoxin inhibitory concentrations of MFEO were 2.75 and 1.5 mg/ml, respectively. The MFEO was efficacious against a broad spectrum of food deteriorating fungi. MFEO caused decrease in ergosterol content of fungal plasma membrane and enhanced leakage of cellular ions, depicting plasma membrane as the site of action. The MFEO caused reduction in cellular methylglyoxal content, the aflatoxin inducer. This is the first report on MFEO as aflatoxin suppressor. The essential oil may be recommended as plant based food preservative after large scale trials and reduction in methylglyoxal suggests its application for development of aflatoxin resistant varieties through green transgenics.

The Bacteriological Properties of Bacillus Strain TM-I-3 and Analysis of the Volatile Antifungal Compounds Emitted by this Bacteria.

Previously, we isolated and examined a bacterial strain designated as TM-I-3, belonging to the genus Bacillus, from soil in Nagasaki, Japan. This bacterium was able to inhibit the growth of molds, without coming into direct contact with them. Non-contact antifungals are capable of providing multidirectional inhibition and may contribute to disease prevention. In this study, we revealed the bacteriological properties of TM-I-3 and evaluated the antifungal activity of the compounds emitted from this bacterium. In addition, we analyzed the antimicrobial substances released from TM-I-3 using GC/MS to elucidate the mechanism of its action. Antimicrobial compounds from strain TM-I-3 were identified as acetic acid, propanoic acid, isovaleric acid, 2-methylbutanoic acid, and benzaldehyde, which are all reported to have antimicrobial activity. TM-I-3 demonstrated possible efficacy in inhibiting the growth of Aspergillus fumigatus, Cladosporium cladosporioides and Penicillium expansum, which may lead to inhibition of common fungal contaminants of household products and prevention of some pulmonary diseases.

Total syntheses of surinone B, alatanones A-B, and trineurone A.

The total syntheses of four polyketides, surinone B (1), alatanones A-B (2-3), and trineurone A (4) were accomplished through an efficient and unified strategy via one-pot C-acylation reaction coupling 1,3-cyclohexadiones with EDC-activated acids under mild conditions. Alatanone A (2) was found to be a potent anti-microbial agent against Gram-positive and Gram-negative bacteria with MIC 31.25 µg/ml while alatanone B (3) was found to be a potent anti-fungal agent against Cladosporium cladosporioides with MIC 62.5 µg/ml compared to cycloheximide MIC 125 µg/ml. Our methodology allows performing kilogram scale of these scarce polyketides for the development of new antimicrobials.

Sensitivity of food spoilage fungi to a smoke generator sanitizer.

Smoke generator sanitizers are easy to handle and can access to hard-to-reach places. They are a promising alternative for controlling food and air borne fungi, which are known to cause losses in the bakery, meat, and dairy industries. Therefore, the present study aimed to evaluate the efficiency of a smoke generator sanitizer based on orthophenylphenol against ten fungal species relevant to food spoilage. The tests were carried out according to the norms by the French protocol NF-T-72281, with adaptations specific for disinfectants diffused in the air. The tests were performed in an enclosed room of approximately 32 m3. Aspergillus brasiliensis (ATCC 16404), Candida albicans (ATCC 10231), Aspergillus flavus (ATCC 9643), Aspergillus chevalieri (IMI 211382), Cladosporium cladosporioides (IMI 158517), Lichtheima corymbifera (CCT 4485), Mucor hiemalis (CCT 4561), Penicillium commune (CCT 7683), Penicillium polonicum (NGT 33/12), and Penicillium roqueforti (IMI 217568) were exposed to the smoke generator sanitizer for 7 h. The product was efficient against C. albicans and C. cladosporioides, although it was unable to reduce 4 log of the other tested species. The variable sensitivity of the fungal species to the sanitizer emphasizes the importance of confronting a target microorganism (causing problems in a specific food industry) with the sanitizer aiming to control it and obtain satisfactory results in hygiene programs.

Evaluation of disinfectants in order to eliminate fungal contamination in computer keyboards of an integrated health center in Piauí, Brazil.

This quantitative and qualitative study aimed to evaluate the level of fungal contamination in computer keyboards from an Integrated Health Center (IHC) at Piauí, Brazil, and to evaluate the efficacy of 50% sodium bicarbonate and 50% alcoholic vinegar solutions to eliminate these microorganisms. Ten keyboards from six sectors of the IHC were chosen randomly, and the collection was performed in three situations: (i) before of disinfection, (ii) after disinfection with solution of sodium bicarbonate, and (iii) after disinfection with solution of alcoholic vinegar. Samples were inoculated in Petri dishes with dextrose agar potato plus chloramphenicol and incubated at room temperature for 72 h. All keyboards were contaminated with opportunistic fungi, with Cladosporium cladosporioides (29.4%) being the most frequent species, followed by Curvularia lunata (17.6%) and Aspergillus niger, Alternaria alternata, and Curvularia clavata with 11.8% each. The two solutions were proven to be efficient in eliminating fungal contamination; however, the sodium bicarbonate solution caused esthetic damages in keyboards. In addition, this study is the first report of the antifungal activity of alcoholic vinegar in filamentous fungi. Based on our findings, we suggest a daily disinfection of keyboards with a 50% vinegar solution plus adequate hygiene from the hands of professionals before and after the use of the computer and its annexes, as key actions to reduce nosocomial infections, particularly in economically disadvantaged countries.

Physiological and RNA-seq analyses provide insights into the response mechanism of the Cf-10-mediated resistance to Cladosporium fulvum infection in tomato.

KEY MESSAGE: Based on the physiological and RNA-seq analysis, some progress has been made in elucidating the Cf-10-mediated resistance responses to C. fulvum infection in tomato. GO and KEGG enrichment analysis revealed that the DEGs were significantly associated with defense-signaling pathways like oxidation-reduction processes, oxidoreductase activity and plant hormone signal transduction. Leaf mold, caused by the fungus Cladosporium fulvum, is one of the most common diseases affecting tomatoes worldwide. Cf series genes including Cf-2, Cf-4, Cf-5, Cf-9 and Cf-10 play very important roles in resisting tomato leaf mold. Understanding the molecular mechanism of Cf gene-mediated resistance is thus the key to facilitating genetic engineering of resistance to C. fulvum infection. Progress has been made in elucidating two Cf genes, Cf -19 and Cf -12, and how they mediate resistance responses to C. fulvum infection in tomato. However, the mechanism of the Cf-10- mediated resistance response is still unclear. In the present study, RNA-seq was used to analyze changes in the transcriptome at different stages of C. fulvum infection. A total of 2,242 differentially expressed genes (DEGs) responsive to C. fulvum between 0 and 16 days post infection (dpi) were identified, including 1,501 upregulated and 741 downregulated genes. The majority of DEGs were associated with defense-signaling pathways including oxidation-reduction processes, oxidoreductase activity and plant hormone signal transduction. Four DEGs associated with plant-pathogen interaction were uniquely activated in Cf-10 tomato and validated by qRT-PCR. In addition, physiological indicators including reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were measured at 0-21 dpi, and hormone expression [Jasmonic acid (JA) and salicylic acid (SA)] was estimated at 0 and 16 dpi to elucidate the mechanism of the Cf-10-mediated resistance response. C. fulvum infection induced the activities of POD, CAT and SOD, and decreased ROS levels. JA was determined to participate in the resistance response to C. fulvum during the initial infection period. The results of this study provide accountable evidence for the physiological and transcriptional regulation of the Cf-10-mediated resistance response to C. fulvum infection, facilitating further understanding of the molecular mechanism of Cf-10-mediated resistance to C. fulvum infection.

Chemical investigation of metabolites produced by an endophytic fungi Phialemonium curvatum from the leaves of Passiflora edulis.

Phialemonium curvatum, an endophytic fungus isolated from the leaves of Passiflora edulis was cultured in potato dextrose broth (PDB) media and chromatographic separation of the EtOAc extract of the broth and mycelium led to the isolation of 4-hydroxybenzoic acid (1), 3-indole acetic acid (2), solaniol (3), uracil (4), uridine (5) and glycerol (6). Compound 2 showed a weak antifungal activity against Cladosporium cladosporioides. This is the first report of the isolation of the endophytic fungus P. curvatum from P. edulis and complete 13CNMR assignments of 3.

Synthesis of secondary metabolites by Cladosporium resinae (NRL-6437) under different growth media and chemical inducers and their pharmaceutical activity.

The role of different growth media and chemical enhancer on synthesis of secondary metabolites Cladosporium resinae (NRL-6437) was investigated for their in vitro biological activities. Cladosporium resinae (NRL-6437) were grown in various nutrient media (Czapeak-dox Broth (CB), Czapeak Yeast-extract Broth (CYB), Yeast Extract Sucrose (YES), Potato Dextrose Broth (PDB) and Czapeak-dox (supplemented with glucose and starch) Broth (CGSB) for the production of metabolites. Two chemical epigenetic modifiers (suberoyl-anilide hydroxamic acid (SAHA) and 5-azacytidine (5-AZA) were also used for the expression of silent genes for secondary metabolite production. Our results indicated that among different media, Czapeak yeast extract broth produced more secondary metabolites. Application of 15mM of both modifiers was effective for the expressions of silent genes resulting in an increased metabolites production. Secondary metabolites extracted in ethyl acetate and fractionized in n-Hexane were also tested for their biological activity. The secondary metabolites revealed varying degrees of growth inhibitions of the tested organisms. Similarly, these metabolites were also active against brine shrimps and Lemna.

Inactivation of three genera of dominant fungal spores in groundwater using chlorine dioxide: Effectiveness, influencing factors, and mechanisms.

Fungi in aquatic environments received more attention recently; therefore, the characteristics of inactivation of fungal spores by widely used disinfectants are quite important. Nonetheless, the inactivation efficacy of fungal spores by chlorine dioxide is poorly known. In this study, the effectiveness of chlorine dioxide at inactivation of three dominant genera of fungal spores isolated from drinking groundwater and the effects of pH, temperature, chlorine dioxide concentration, and humic acid were evaluated. The inactivation mechanisms were explored by analyzing the leakage of intracellular substances, the increase in extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), and proteins as well as the changes in spore morphology. The kinetics of inactivation by chlorine dioxide fitted the Chick-Watson model, and different fungal species showed different resistance to chlorine dioxide inactivation, which was in the following order: Cladosporium sp.>Trichoderma sp. >Penicillium sp., which are much more resistant than Escherichia coli. Regarding the three genera of fungal spores used in this study, chlorine dioxide was more effective at inactivation of fungal spores than chlorine. The effect of disinfectant concentration and temperature was positive, and the impact of pH levels (6.0 and 7.0) was insignificant, whereas the influence of water matrices on the inactivation efficiency was negative. The increased concentration of characteristic extracellular substances and changes of spore morphology were observed after inactivation with chlorine dioxide and were due to cell wall and cell membrane damage in fungal spores, causing the leakage of intracellular substances and death of a fungal spore.

Galvanic microcells as control agent of indoor microorganisms.

Today, fungicides are part of the basic tool kit for indoor surface maintenance. However, fungi develop resistance to fungicides, which consequently accelerates the evolution of virulence. Fungicides also carry the risk of adverse effects in humans. Galvanic microcells are a new tool for fungal control on indoor surfaces. We used two types of electrodes, Zn and Cu, with two potential anti-fungal mechanisms: the oligodynamic action of the metal ions themselves and the electricidal effect of the current between the electrodes. The size of the inhibition zone is related to the distance between the electrodes. We hypothesized that the unique geometric properties of the observed inhibition zone could be modelled using multi foci curve Cassini ovals. Moreover, the size of the inhibition zone possessed two maximum values, while the shape of the observed inhibition zones correlated with the shape of the electric field strength. The control activity of the galvanic microcells correlated with decreasing water content in building materials. Thus, this acute antifungal system works the best in damp building environments where the risk of fungal contamination is highest.

Chemical Composition and in vitro Biological Activities of Essential Oils from Conchocarpus fontanesianus (A. St.-Hil.) Kallunki & Pirani (Rutaceae).

This study aimed at assessing the chemical composition of the essential oils from leaves and fruits of Conchocarpus fontanesianus, an endemic Brazilian species of Rutaceae. The plant material was harvested from two regions of the Atlantic rainforest in the State of São Paulo. The volatile compounds in the essential oils were extracted by hydrodistillation (HD), and analyzed by GC/FID and GC/MS, allowing the quantification and identification of 54 components in total, which comprise about 97% of the total oil composition. From the leaves collected in Caraguatatuba and Juréia-Itatins, the major volatile compounds identified were as follows: spathulenol (22.32% and 16.67%) and α-cadinol (9.7% and 14.76%). However, ß-myrcene (34.56%), (+)-epi-bicyclosesquiphellandrene (8.71%), and bicyclogermacrene (5.80%) were dominant in the fruits collected only in Juréia-Itatins. The in vitro biological activities were tested to evaluate the cytotoxic, antifungal, and antioxidant potential of essential oils from leaves and fruits.

[Inactivation Efficiency and Mechanism of Three Dominant Fungal Spores in Drinking Groundwater by Chlorine].

The outbreak of fungi in drinking groundwater sources can produce odor, cause toxicity and form lots of visible flocs, which seriously affect the drinking water quality. In this study, the inactivation efficiency of three dominant fungal spores Trichoderma, Penicillium, Cladosporium by chlorine was conducted, and the inactivation mechanism was explored by monitoring the hydrophobicity, the leakage of intracellular substances, the increase of extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA) and proteins, and the change of spores' morphology. The results showed that the inactivation of fungal spores was consistent with first-order kinetics and satisfied the Chick model. The resistance to chlorine was in sequence of Trichoderma > Penicillium > Cladosporium, the larger size the fungal spores and the more hydrophilicity the fungal spores, the higher the inactivation efficiency. Chlorination resulted in the remarkable leakage of intracellular compounds, the increase of extracellular characteristic compounds (ATP, DNA and protein), the damage of the cell surface, and the fungal spores recessed and wrinkled. In summary, chlorine firstly reacted with spores' surface and reduced their cultivability, and then resulted in the damage to the permeability barrier of the spores and the release of intracellular characteristic compounds, and finally the viability of spores was damaged.

Phenylpropanoid-rich Essential Oils of Piper Species from the Amazon and their Antifungal and Anti-cholinesterase Activities.

The essential oils (EOs) from aerial parts of Piper aduncum, P. callosuin and P. marginatum, collected from the Amazon region of Brazil, were analyzed by GC-MS and then evaluated for their antifungal and anticholinesterase activities. The essential oils were dominated by phenylpropanoids, such as dillapiole (73.0%) in P. aduncum, safrole (66.0%) in P. callosum and 3,4-methylenedioxypropiophenone (21.8%) in P. inarginatum. The analyzed oils showed low to moderate antifungal activity; with detection limits (DL) from 10 to 100 pg against Cladosporium cladosporioides and C. sphareospermum. In the anticholinesterase (AChE) evaluation, the oils of P. callosum (DL = 0.01 ng) and P. marginatum (DL = 0.01 ng) were one hundred times more potent than the standard physostigmine (DL = 1.0 ng). Molecular docking analysis showed that phenylpropanoids docked reasonably well with acetyleholinesterase and may be responsible for the anti-AChE activities of the Piper EOs. This is the first presentation about acetylcholinesterase inhibition by methylenedioxyphenyl-propanoids.

Antifungal potential of Avicennia schaueriana Stapf & Leech. (Acanthaceae) against Cladosporium and Colletotrichum species.

UNLABELLED: There is significant interest in research to develop plant extracts with fungicidal activities that are less harmful to the environment and human health than synthetic fungicides. This study aimed to evaluate the antifungal activity of the extracts of Avicennia schaueriana against Colletotrichum and Cladosporium species and to identify the compounds responsible for the activity. Leaves and stems of A. schaueriana were extracted with ethanol and partitioned with petroleum ether, chloroform and ethyl acetate. The antifungal activity of such extracts was tested by bioautography against Cladosporium sphaerospermum, Cladosporium cladosporioides and Colletotrichum lagenarium. Ethanolic extracts, petroleum ether and chloroform fractions of stems had the highest antifungal activity with several active bands (Rf = 0·72 and Rf = 0·55). In the agar dilution assay, ethanolic extract, petroleum ether and chloroform fractions of stems were the most efficacious, presenting 85, 62 and 63% growth inhibition of Colletotrichum gloeopsporioides and minimum inhibitory concentration values between 1 and 1·5 mg ml(-1) , respectively. Analysis carried out using gas chromatography coupled to a mass spectrometry of petroleum ether and chloroform fractions allowed the identification of fatty acids methyl esters, lupeol and naphthoquinones such as lapachol, α-lapachone, naphtho[2,3-b]furan-4,9-dione, 2-isopropyl- and avicenol-C. We may infer that the antifungal activity of A. schaueriana is due to the abundance of these compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that Avicennia schaueriana extracts have a high potential for the growth inhibition of Colletotrichum and Cladosporium ssp. and will provide a starting point for discovering new natural products with antifungal activity. Their development is of particular interest to organic production systems where synthetic fungicides cannot be used.

Sulfated steroid-amino acid conjugates from the Irish marine sponge Polymastia boletiformis.

Antifungal bioactivity-guided fractionation of the organic extract of the sponge Polymastia boletiformis, collected from the west coast of Ireland, led to the isolation of two new sulfated steroid-amino acid conjugates (1 and 2). Extensive 1D and 2D NMR analyses in combination with quantum mechanical calculations of the electronic circular dichroism (ECD) spectra, optical rotation, and 13C chemical shifts were used to establish the chemical structures of 1 and 2. Both compounds exhibited moderate antifungal activity against Cladosporium cucumerinum, while compound 2 was also active against Candida albicans. Marine natural products containing steroidal and amino acid constituents are extremely rare in nature.