Inhibitory effects of cassiae semen extract on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in model system.

Introduction: 2-Amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines. Methods: To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC-MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine. Results: The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass-charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde. Discussion: Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.

A fresh-cut papaya freshness prediction model based on partial least squares regression and support vector machine regression.

This study investigated the physicochemical and flavor quality changes in fresh-cut papaya that was stored at 4 °C. Multivariate statistical analysis was used to evaluate the freshness of fresh-cut papaya. Aerobic plate counts were selected as a predictor of freshness of fresh-cut papaya, and a prediction model for freshness was established using partial least squares regression (PLSR), and support vector machine regression (SVMR) algorithms. Freshness of fresh-cut papaya could be well distinguished based on physicochemical and flavor quality analyses. The aerobic plate counts, as a predictor of freshness of fresh-cut papaya, significantly correlated with storage time. The SVMR model had a higher prediction accuracy than the PLSR model. Combining flavor quality with multivariate statistical analysis can be effectively used for evaluating the freshness of fresh-cut papaya.

First report of leaf blight disease caused by Aspergillus welwitschiae on Persicaria lapathifolia var. salicifolia in China.

Persicaria lapathifolia var. salicifolia (Sibth.) Miyabe, has long been extensively utilized in traditional medicine for its significant medical values (Seimandi et al, 2021). Despite its extensive use, the leaf blight disease of this plant has never been documented in China. However, in September 2023, the symptoms of leaf blight disease were observed on P. lapathifolia var. salicifolia on the campus of Zhejiang Normal University (29°8'3″ N, 119°37'47″ E), Zhejiang province, China. The disease incidence was 40% on the 50 plants surveyed, according to the field survey. The progression of leaf pathogenesis is mainly divided into three stages. Early symptoms manifested as the light yellow spots on the edges or tips of the leaves, which subsequently developed into brown or yellow irregular lesions and eventually led to the curling and wilting leaves. Thus, the leaf tissues (5 × 5 mm) from the border of diseased and healthy areas were surface-sterilized in 1% sodium hypochlorite for 3 min, followed by 75% ethanol for 30 s, and rinsed three times with sterile water. After drying on sterile filter paper, the leaf tissues were put on PDA medium and cultured at 25°C for 3 days. Seven purified fungal isolates were obtained, and one representative strain was selected for further identification. After that, the isolate was identified by the combination of morphological studies and molecular analysis. The fungi exhibited rapid growth on PDA, attaining a diameter of 80 to 85 mm in 5 days. The colonies were black with a yellow margin, and the reverse sides were light yellow and partly colorless. Moreover, the conidia were brown to black, smooth to slightly rough, measuring 3.2 to 3.8 µm (n = 30) in diameter, with radiated conidial heads and expanded ampulliform phialides under the optical microscope. Therefore, the isolate's characteristics were consistent with the descriptions of Aspergillus welwitschiae (Bres.) Henn. (Gherbawy et al, 2021). To further identify the isolate, the internal transcribed spacer (ITS) region (Gardeset al, 1993) and the second largest RNA polymerase subunit (RPB2) (Liu et al, 1999) were employed for phylogenetic analysis. The obtained sequences were despot in GenBank (Acc. Nos. OR797058 for ITS, OR797058 for RPB2, respectively), and exhibited a high degree of sequence homology to A. welwitschiae (MK450815, MK450818, LC179911, and LC000572), with 99% to 100% identity. Besides, multilocus phylogenetic analysis showed that the isolate gathered into one clade with A. welwitschiae. Based on the integrated morphological and molecular results, the isolate was determined to be A. welwitschiae. Six healthy 1-year-old P. lapathifolia var. salicifolia were used to verify Koch's postulates. Three leaves were wounded with sterile pins and inoculated with the conidial suspension (107 conidia/mL) of isolates, while plants inoculated with sterile water were used as controls. After sealing with plastic wrap for 24 hours, the plants were cultivated at 25 °C and 85% relative humidity. Necrotic lesions were observed on leaves 10 days after inoculation, while the control leaves remained asymptomatic. The fungi were re-isolated from the diseased leaves and identified as the original ones through morphological and molecular identification, confirming Koch's postulates. While A. welwitschiae has been reported to cause the rot disease of Sisal Bole in Brazil (Duarte et al, 2018) and maize ear in Serbia (Nikolic et al., 2023), to our knowledge, this study marks the first report of A. welwitschiae causing leaf blight on P. lapathifolia var. salicifolia in China, extending the host range to A. welwitschiae.

Translation, cultural adaptation, and validation of the Chinese standardized outcomes in nephrology-hemodialysis fatigue (C-SONG-HD fatigue) scale: a study of Chinese patients undergoing hemodialysis.

OBJECTIVE: This study aimed to translate and culturally adapt the standardized outcomes in nephrology-hemodialysis fatigue (SONG-HD fatigue) scale and to assess the psychometric properties of the Chinese version of the SONG-HD fatigue (C-SONG-HD fatigue) scale. METHODS: Forward and back translations were used to translate the SONG-HD fatigue scale into Chinese. We used the C-SONG-HD fatigue scale to survey Chinese patients undergoing hemodialysis (HD) in China. We examined the distribution of responses and floor and ceiling effects. Cronbach's alpha and McDonald's omega coefficient, intraclass coefficients, and Spearman correlations were used to assess internal consistency reliability, test-retest reliability, and convergent validity, respectively. Responsiveness was also evaluated. RESULTS: In total, 489 participants across southeast China, northwest China, and central China completed the study. The C-SONG-HD fatigue scale had good internal consistency (Cronbach's alpha coefficient 0.861, omega coefficient 0.916), test-retest reliability (intraclass correlation coefficient 0.695), and convergent validity (Spearman correlation 0.691). The analysis of all first-time HD patients did not show notable responsiveness, and only patients with temporary vascular access had good responsiveness with an effect size (ES) of 0.54, a standardized response mean (SRM) of 0.85, and a standard error of measurement (SEM) of 0.77. CONCLUSION: The Chinese version of the SONG-HD fatigue scale showed satisfactory reliability and validity in patients undergoing hemodialysis (HD) in China. It could be used as a tool to measure the fatigue of Chinese HD patients.

Isolation and characterization of cellulose nanocrystals from Chinese medicine residues.

Nanocellulose has become a vital material with excellent and crucial properties in the field of nanotechnology and advanced materials science. Plant-based traditional Chinese medicines are mostly plant rhizomes, which contain a large amount of cellulose, hemicellulose, and lignin. In this study, carboxylated cellulose nanocrystals (CNCs) were prepared from traditional Chinese medicine residues (CMR) by sequential periodate-chlorite oxidation without mechanical treatment. The obtained nanocelluloses were analyzed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffractometry (XRD); the carboxyl content and specific surface area were also measured, simultaneously. XRD results revealed that the crystallinity index decreased after sequential oxidation; however, the cellulose I structure was maintained. From the morphology analysis, the average length and width of CNCs were 139.3 and 10 nm, respectively. From the FTIR analysis, with the particle size decreasing, hydrogen bonds were broken and recombined. TGA results showed that the thermal property was decreased with a reduction of nanocellulose particle size and crystallinity index. This study is the first to refine utilization of traditional Chinese medicine residues as a potential source of cellulose, that is, to prepare nanocellulose efficiently with high carboxyl content which finds its application in nanomaterials.

An Encryption Algorithm for Region of Interest in Medical DICOM Based on One-Dimensional eλ-cos-cot Map.

Today, with the rapid development of the Internet, improving image security becomes more and more important. To improve image encryption efficiency, a novel region of interest (ROI) encryption algorithm based on a chaotic system was proposed. First, a new 1D eλ-cos-cot (1D-ECC) with better chaotic performance than the traditional chaotic system is proposed. Second, the chaotic system is used to generate a plaintext-relate keystream based on the label information of a medical image DICOM (Digital Imaging and Communications in Medicine) file, the medical image is segmented using an adaptive threshold, and the segmented region of interest is encrypted. The encryption process is divided into two stages: scrambling and diffusion. In the scrambling stage, helical scanning and index scrambling are combined to scramble. In the diffusion stage, two-dimensional bi-directional diffusion is adopted, that is, the image is bi-directionally diffused row by column to make image security better. The algorithm offers good encryption speed and security performance, according to simulation results and security analysis.

Preparation and characterization of cellulose nanocrystals from spent edible fungus substrate.

BACKGROUND: Spent edible fungus substrates were identified as potential sources to produce cellulose derivatives, namely purified cellulose and dicarboxyl cellulose nanocrystal (DCNC). Purified celluloses were obtained via chemical treatments and then oxidized by sequential periodate-chlorite without mechanical process. The structural properties of the DCNCs were characterized by transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). RESULTS: XRD results showed that the cellulose I structure was maintained, however, the crystallinity index decreased after oxidation process. The initial pyrolysis temperature of DCNCs ranged from 242 to 344 °C. TEM results revealed that DCNC was rod-shaped with an average length and width of 130.88 nm and 7.3 nm, respectively. The average specific surface area (SSA) was 366.67 m2  g-1 . The carboxyl content was around 3.485 mmol g-1 . Finally, the adsorption capacity for contaminations was 76.98, 126.22, 64.44 and 9.63 mg g-1 for copper ion (Cu2+ ), lead ion (Pb2+ ), chromium (Cr3+ ) and amoxicillin (AMX), respectively. CONCLUSION: This work showed a sequentially chemical oxidation for preparing nanocellulose from secondary agricultural waste with many functional applications. © 2021 Society of Chemical Industry.

Inhibitory Effects of Carbazomycin B Produced by Streptomyces roseoverticillatus 63 Against Xanthomonas oryzae pv. oryzae.

The present manuscript highlights the potential role of Streptomyces roseoverticillatus 63 (Sr-63) against Xanthomonas oryzae pv. oryzae (Xoo), which is the cause of a disastrous bacterial leaf blight disease with rice worldwide. The disease suppression was achieved under greenhouse conditions. A foliar spray of the fermentation broth of Sr-63 significantly reduced the leaf blight symptoms with rice in Xoo inoculated rice plants. Furthermore, we observed that the carbazomycin B, isolated from the fermentation broth of Sr-63, was demonstrated to have antibacterial activity against Xoo with a minimum inhibitory concentration (MIC) of 8 µg mL-1. The results indicated that carbzomycin B hampered the membrane formation of Xoo, reduced the production of xanthomonadin and extracellular polymeric substance (EPS). The fourier transform infrared spectroscopic (FT-IR) indicated that carbazomycin B changed the components of the cell membrane, then caused a change of the cell surface hydrophobicity of Xoo. Scanning electron microscopy revealed that the Xoo cells treated with carbazomycin B exhibited apparent structural deformation. The results also indicated that carbazomycin B had a negative impact on the metabolism of Xoo, carbazomycin B reduced the activity of malate dehydrogenase (MDH) activity and suppressed the protein expression of Xoo. Overall, our data suggests that Streptomyces roseoverticillatus 63 is a promising biocontrol agent that could be used to combat the bacterial leaf blight diseases of rice.

Screening and identification of Aspergillus activity against Xanthomonas oryzae pv. oryzae and analysis of antimicrobial components.

To screen for Aspergillus activity against Xanthomonas oryzae pv. oryzae and analyse the antimicrobial components involved, 60 Aspergillus spp. were isolated and purified from fruits, soil and other habitats. As-75, an Aspergillus strain that can antagonize Xanthomonas oryzae pv. oryzae, was identified based on the zone of inhibition formed during co-culture. According to morphological, ITS rDNA gene sequencing and phylogenetic tree results, the strain showed close homology to Aspergillus sclerotiorum. The biochemical characterization tests showed that the fermentation broth of strain As-75 exhibited a high capacity for environmental adaptation. The results of the antimicrobial spectrum experiments demonstrated that As-75 exhibited fairly strong antagonistic activity against five plant pathogenic fungi and six plant pathogenic bacteria in vitro. The fermentation broth of strain As-75 displayed maximum stability under fluorescent illumination at temperatures below 60°C at pH 6.5. A substance with antagonistic activity was obtained from strain As-75 via fractional extraction, silica gel column chromatography and thin-layer chromatography. Through mass spectrometry, nuclear magnetic resonance and electrospray ionization mass spectrometry (ESI-MS) analyses, the target compound was identified as (2Z)-2-butenedioic acid-2-(1-methylethenyl)-4-methyl ester; its molecular weight of 170.06 daltons and formula of C8H10O4 identify it as a novel compound. Trials of the preventative and curative effects demonstrated that compound S1 exhibited a better control efficiency than the control against rice bacterial blight. Additionally, the M1 processing method was better, and the efficiency of compound S1 in preventing rice bacterial blight in six rice varieties, TN1, IR24, ZF802, Zhonghua 11, Wuyunjing 21, and Nipponbare, was 78.3%, 77.5%, 74.2%, 75.3%, 70.9%, and 72.1%, respectively.

Cytotoxic triterpenes from the acid hydrolyzate of Gynostemma pentaphyllum saponins.

One new dammarane-type triterpene, gypsapogenin A (1), was isolated from the acid hydrolyzate of total saponins from Gynostemma pentaphyllum (Thunb.) Makino, together with two known compounds, (20S,24S)-3ß,20,21ß,23ß,25-pentahydroxy-21,24-cyclodammarane (2) and (23S)-3ß-hydroxydammar-20,24-dien-21-oic acid 21,23-lactone (3). Its structural elucidations were accomplished mainly on the basis of the interpretation of spectroscopic data, such as IR, HR-TOF-MS, and NMR. The cytotoxic activities were evaluated against HepG2 and A549 human cancer cell lines.

Proteomic Analysis of the Antibacterial Mechanism of Action of Juglone against Staphylococcus aureus.

Juglone is a plant-derived 1,4-naphthoquinone with confirmed antibacterial activity. However, the mechanism of action of juglone against Staphylococcus aureus remains unclear. Possible mechanisms were explored by a proteomic analysis of S. aureus proteins that are inhibited by juglone. Two-dimensional gel electrophoresis revealed that 21 protein spots were differentially expressed between juglone-treated and untreated cells of which 13 were identified. A bioinformatic analysis revealed that proteins participating in protein synthesis, the tricarboxylic acid cycle, as well as DNA and RNA synthesis were inhibited by juglone, thus leading to cell collapse. These findings provide clues regarding the mechanism of action of juglone, which can be effective for treating cases of S. aureus infection.

Antibacterial Activity of Juglone against Staphylococcus aureus: From Apparent to Proteomic.

The proportion of foodborne disease caused by pathogenic microorganisms is rising worldwide, with staphylococcal food poisoning being one of the main causes of this increase. Juglone is a plant-derived 1,4-naphthoquinone with confirmed antibacterial and antitumor activities. However, the specific mechanism underlying its antibacterial activity against Staphylococcus aureus remains unclear. To elucidate the mechanism underlying its antibacterial activity, isobaric tags for relative and absolute quantitation methods of quantitative proteomics were applied for analysis of the 53 proteins that were differentially expressed after treatment with juglone. Combined with verification experiments, such as detection of changes in DNA and RNA content and quantification of oxidative damage, our results suggested that juglone effectively increased the protein expression of oxidoreductase and created a peroxidative environment within the cell, significantly reducing cell wall formation and increasing membrane permeability. We hypothesize that juglone binds to DNA and reduces DNA transcription and replication directly. This is the first study to adopt a proteomic approach to investigate the antibacterial mechanism of juglone.

Protective effects of grape seed extract fractions with different degrees of polymerisation on blood glucose, lipids and hepatic oxidative stress in diabetic rats.

The purpose of this study was to evaluate the effect of grape seed procyanidin (GSPE) fractions with different degrees of polymerisation (DPs) on blood glucose, lipids and hepatic oxidative stress in diabetic rats. Diabetic rats received a daily oral supplement of GSPE with different DPs for 6 weeks. During this period, blood glucose, body weight and food intake were assessed weekly. At the end of the experiment, serum lipid and hepatic oxidative stress were assessed compared with those of rats that did not receive GSPE. GSPE significantly decreased blood glucose, serum lipids and hepatic oxidative stress. Moreover, these effects were significantly better in the groups administered the oligomeric rather than the polymeric forms. These results demonstrate that GSPE has a positive effect on diabetes in rats, and the oligomeric form of GSPE may be more protective than other forms.

Phytotoxic and antibacterial metabolites from Fusarium proliferatum ZS07 isolated from the gut of long-horned grasshoppers.

In the proceeding of screening new bioactive natural products, the ethyl acetate extract of the fermentation broth of Fusarium proliferatum ZS07, a fungus residing in the gut of long-horned grasshoppers (Tettigonia chinensis), was found possessing selective phytotoxic activity against the radicle growth of Amaranthus retroflexus L. Bioactivity-guided fractionation lead to the isolation of six fungal metabolites 1-6, including a new polyketide derivate O-methylated SMA93 (2) and five known compounds SMA93 (1), rhodolamprometrin (3), radicinin (4), dehydroallogibberic acid (5), and 3-methyl-6,8-dihydroxyisocoumarin (6). Their structures were identified on the basis of spectroscopic analysis and by comparison of the corresponding data to those reported in the literature previously. Phytotoxic effects of the four isolated compounds 1-4 on the radicle growth of A. retroflexus L. seeds were investigated under laboratory conditions, and compounds 2 and 4 showed good phytotoxic activity in the concentration of 100 µg/mL, with the inhibition rates of 83.0 and 65.2%, respectively. Furthermore, the antibacterial activity of compounds 1-5 were evaluated against selected bacteria. Compounds 1-3 were found to possess potent antibacterial activity against Bacillus subtilis (ATCC 6633), with the minimum inhibitory concentration (MIC) values of 3.13-12.50 µg/mL, while Escherichia coli (ATCC 8739) and Salmonella typhimurium [CMCC(B) 50115] were not susceptible. These results suggest that the new polyketide derivate 2 and known compounds 1, 3, and 4 have potential to be used as biocontrol agents in agriculture.

Alkali extraction and in vitro antioxidant activity of Monascus mycelium polysaccharides.

In the present work, alkali extraction technology was used to optimize the extraction of Monascus mycelium polysaccharides for the first time. The extracting parameters of alkali extracted Monascus mycelium polysaccharides were optimized by Box-Behnken design (BBD). The optimum conditions were extraction temperature 49 °C, alkali concentration 7%, solvent/material ratio 23:1 (ml/g) and extraction time 2.3 h with an enhanced yield of 10.1%, compared with the yield 4.76% of hot water extraction, indicating that alkali extraction is a more efficient way. In order to discuss the biological activity of alkali extracted polysaccharides, we compared the in vitro antioxidant activity of alkali extracted polysaccharides (AMP) with hot water extracted polysaccharides (HMP). The result showed that AMP have the similar capability of scavenging both superoxide radical and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical of HMP in vitro. Therefore, alkali extraction technology is not only a high-efficiency way to extract AMP, but also can retain the natural antioxidant activities of AMP, which can be used in pharmaceutical and food industries.

Rhodamine B induces long nucleoplasmic bridges and other nuclear anomalies in Allium cepa root tip cells.

The cytogenetic toxicity of rhodamine B on root tip cells of Allium cepa was investigated. A. cepa were cultured in water (negative control), 10 ppm methyl methanesulfonate (positive control), and three concentrations of rhodamine B (200, 100, and 50 ppm) for 7 days. Rhodamine B inhibited mitotic activity; increased nuclear anomalies, including micronuclei, nuclear buds, and bridged nuclei; and induced oxidative stress in A. cepa root tissues. Furthermore, a substantial amount of long nucleoplasmic bridges were entangled together, and some nuclei were simultaneously linked to several other nuclei and to nuclear buds with nucleoplasmic bridges in rhodamine B-treated cells. In conclusion, rhodamine B induced cytogenetic effects in A. cepa root tip cells, which suggests that the A. cepa root is an ideal model system for detecting cellular interactions.

Synthesis, interaction with DNA and antiproliferative activities of two novel Cu(II) complexes with Schiff base of benzimidazole.

Two novel copper(II) complexes with Schiff base of benzimidazole [Cu(L)Cl]2·CH3OH have been synthesized. HL(1) (N-(benzimidazol-2-ymethyl)-5-chlorosalicylideneimine, C15H11ClN3O) and HL(2) (N-(benzimidazol-2-ymethyl)-salicylideneimine, C15H12N3O) are ligands of complex (1) and complex (2), respectively. The complexes were characterized by elemental analysis, IR, UV-Vis, TGA and X-ray diffraction. Within the complexes, Cu(II) ions were four coordinated by two nitrogen atom of azomethine and imine, one phenolic oxygen atom from HL and one chloride atom. A distorted quadrilateral structure was formed. Complex (1) crystallized in the triclinic crystal system. Results showed that π-π stacking effect occurred due to the existence of aromatic ring from Schiff base and hydrogen bonding between methanol and adjacent atoms. The DNA binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra and viscosity measurements. Results indicated that complexes bound to DNA via partial intercalation mode. The DNA binding constants Kb/(L mol(-1)) were 1.81×10(4) (1), 1.37×10(4) (2), 6.27×10(3) (HL(1)) and 3.14×10(3) (HL(2)) at 298 K. The title complexes could quench the emission intensities of EB-DNA system significantly. The results of agarose gel electrophoresis indicated complex (1) could cleave supercoiled DNA through the oxidative mechanism. The inhibition ratios revealed that complex (1) and HL(1) had strong antiproliferative activities against human breast cancer cells (MCF-7) lines and human colorectal cancer cells (COLO205) lines in vitro. The antiproliferative activities of complex (1) against MCF-7 lines (IC50=16.9±1.5 µmol L(-1)) and against COLO205 lines (IC50=16.5±3.4 µmol L(-1)) is much stronger than that of HL(1), which had the potential to develop anti-cancer drug.

Cu-doped zinc oxide and its polythiophene composites: preparation and antibacterial properties.

Cu-doped zinc oxide and its polythiophene nanocomposites were prepared by the Sol-Gel and in situ polymerization methods, respectively. The structures, morphologies and compositions of the samples were characterized. The antibacterial properties of the samples on three kinds of strains were determined by using powder inhibition zones, minimum inhibitory concentrations and minimal bactericidal concentrations. The study confirmed that the antibacterial activities of the composites were better than those of their each component. The antibacterial mechanisms of the samples were discussed further.

Antifungal activities of metabolites produced by a termite-associated Streptomyces canus BYB02.

Two main antifungal metabolites resistomycin and tetracenomycin D were isolated and purified from a termite-associated Streptomyces canus BYB02 by column chromatography. The structures of isolated compounds were determined on the basis of extensive spectroscopic analysis. Resistomycin possessed strong activities against mycelial growth of Valsa mali (IC(50) = 1.1 µg/mL) and Magnaporthe grisea (IC(50) = 3.8 µg/mL), which were comparable to those of referenced cycloheximide, with IC(50) values of 2.3 and 0.3 µg/mL, respectively. A further spore germination test showed that resistomycin exhibited potent reduction in spore germination for M. grisea , with an IC(50) value of 5.55 µg/mL. Finally, the in vivo antifungal activity experiment showed that resistomycin possessed significant preventive efficacy against rice blast, which was more potent than that of referenced carbendazim, with control efficacies of 66.8 and 58.7%, respectively. The present results suggest that resistomycin has potential to be used as a fungicide.

Phytotoxic and antifungal metabolites from Curvularia sp. FH01 isolated from the gut of Atractomorpha sinensis.

Two main phytotoxic and antifungal phthalic acid butyl isobutyl ester (1) and radicinin (2) were isolated from the culture of Curvularia sp. FH01, a fungus residing in the Atractomorpha sinensis gut. The structures of isolated metabolites were established on the basis of spectral analysis. Metabolites 1 and 2 exhibited significant phytotoxic activity against the radical growth of Echinochloa crusgalli with their IC(50) values of 61.9 and 5.9 µg/mL, respectively, which were comparable to that 2,4-dichlorophenoxyacetic acid (2.0 µg/mL) used as a positive control. The antifungal test results showed that compound 2 possessed strong antifungal activity against Magnaporthe grisea (IC(50)=16.3 µg/mL) and Valsa mali (IC(50)=18.2 µg/mL). The findings of the present study suggest that bioactive properties of the fungus FH01 can be attributed to its major components, phthalic acid butyl isobutyl ester and radicinin, and both agents have a potential to be used as herbicide and fungicide.