Controlled-Release of Plant Volatiles:New Composite Materials of Porous Carbon-Citral and Their Fungicidal Activity against Exobasidium vexans

Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous carbon(BC)was developed to overcome the drawback of Eo.New composite materials were prepared by loading Eo on tea stem porous carbon(BC@Eo),and their controlled-release fungicidal activity against Exobasidium vexans was assessed.BC with a large specific surface area of 1001.6 m2/g and mesoporous structure was fabricated through carbonization tempera-ture of 700℃.The BC@Eo materials were characterized using Fourier-transform infrared spectroscopy and X-ray powder diffraction.The results suggested that chemical and physical interactions occurred in BC@Eo.The Eo release profile suggested a biphasic pattern with an initial fast release on days 1–14 and a subsequent controlled phase on days 14–30.The in vitro cumulative release percentage of Eo from BC@Eo was 51%during one month,and this result was significantly lower than that from free Eo(cumulative release percentage of Eo of 82%in one week).The anti-fungal activities of Eo and BC@Eo against E.vexans were determined using the inhibition zone method.The results indicated that Eo and BC@Eo formed large inhibition zones of 19.66±0.79 and 21.92±0.77 mm,respectively.The influence on the hyphal structure of E.vexans was observed by scanning electron microscopy on day 30.The hyphal structure of E.vexans treated with BC@Eo was more shrunken than that treated with Eo at 30 days,suggesting that BC@Eo prolongs the fungicidal activity against E.vexans.This study demonstrated that the encapsulation of Eo in BC for developing the BC@Eo materials could be a promising strategy to inhibit volatility and maintain the fungicidal activity of Eo and provide a potential alternative for the reuse of abundant tea biomass waste resources.

Synthesis and Fungicidal Activities of 2-Alkylthio-5-(3,4,5-tribenzyloxyphenyl)-1,3,4-oxadiazoles

Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.

Synthesis, Crystal Structure and Fungicidal Activity of 3-(Difluoromethyl)-1-methyl-N-((2-(trifluoromethyl)phenyl) carbamoyl)-1H-pyrazole-4-carboxamide

The title compound 3-(difluoromethyl)-1-methyl-N-((2-(trifluoromethyl)phenyl)-carbamoyl)-1 H-pyrazole-4-carboxamide(C14 H11 F5 N4 O2) was synthesized, and its structure was confirmed by 1 H NMR, H RMS and X-ray diffraction. It crystallizes in monoclinic system, space group P21/n with a = 6.994(3), b = 13.860(6), c = 15.308(7)A,β= 97.632(6)°, V = 1470.8(11) A^3,Z = 4, the final R = 0.0692 and wR = 0.2108 for 3989 observed reflections with Ⅰ> 2σ(Ⅰ). The preliminary biological test shows that the title compound has moderate fungicidal activities against Pseudomonas syringae.

Synthesis, Crystal Structure and Fungicidal Activity of N-(4-tert-buty)-5-(1,2,4-triazol-1-yl)thiazol-2-yl)propionamide

The title compound has been synthesized by the reaction of 4-tert-butyl-5-（1,2,4- triazol-1-yl）-2-aminothiazole with propionic anhydride, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with α = 18.441（2）, b = 8.3284（9）, c = 19.257（2） A, Z = 8, V = 2957.5（5） A3, Mr = 279.37, Dc = 1.255 mg/m3, S = 1.033, μ =0.219 mm^-1, F（000） = 1184, the final R = 0.0349 and wR = 0.0876 for 2629 observed reflections （I 〉 2σ（I））. X-ray crystal structure presents the intermolecular N–H···N hydrogen bond, which plays an important role in stabilizing the crystal structure. The preliminary bioassay indicates that the title compound exhibits potent fungicidal activity against R. Solani （25 mg/L） with inhibition rate of 80.0%.

Synthesis, Crystal Structure and Fungicidal Activity of (Z)-3,3-Dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one O-2-Chlorobenzyl Oxime Nitrate

The title compound has been synthesized by the reaction of 3,3-dimethyl-1-（1H-1,2,4-triazol-1-yl）butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65～68% HNO3. Its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 14.5481（8）, b = 9.3351（5）, c = 13.1911（7） , β = 98.9450（10）°, Z = 4, V = 1769.67（17） 3, Mr = 369.81, Dc = 1.388 g/cm3, S = 1.06, μ = 0.247 mm-1, F（000） = 776, the final R = 0.0352 and wR = 0.0960 for 3069 observed reflections （I 2σ（I））. X-ray crystal structure presents the intramolecular N–H…O hydrogen bond. The packing is nearly parallel without π-π stacking interactions between two adjacent phenyl rings and stabilized by Van der Waals force. The preliminary bioassay shows that the title compound possesses fungicidal activity against Gibberella zeae at the dosage of 25 mg/L.

Synthesis,Crystal Structure and Fungicidal Activity of(E)-2-[(4-tert-Butyl-5-(4-methoxybenzyl)thiazol-2-ylimino)methyl]phenol

The title compound （E）-2-[（4-tert-butyl-5-（4-methoxybenzyl）thiazol-2-ylimino）methyl]phenol was synthesized by the reaction of 5-（4-methoxybenzyl）-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 5.9362（8）, b = 11.5070（15）, c = 29.460（4）A, β= 97.326（3）°, V = 1995.9（5） A^3, Z = 4, F（000） = 808, C22H24N2O2S, Mr= 380.49, De= 1.266 g/cm^3, S = 1.031,μ = 0.181 mm^-1, the final R = 0.0474 and wR = 0.1441 for 4327 observed reflections （I 〉 2σ（I））. Intramolecular O-H…N hydrogen bond is observed in the crystal. The preliminary bioassay showed that the title compound exhibits 95% inhibition rate against Rhizoctonia solani at the test concentration of 500 mg/L.

Synthesis, Crystal Structure and Fungicidal Activity of 3-(4-Chloro-3-ethyl-1-methyl-1H-pyrazol-5-yl)-6-(E)phenylvinyltriazolo[3,4-b]-1,3,4-thiadiazole

The crystal structure of the title compound 3 (4 Chloro 3 ethyl 1 methyl 1H pyrazol 5 yl) 6 (E)phenylvinyltriazolo[3,4 b] 1,3,4 thiadiazole (C 17 H 15 ClN 6S, M r =370.87) was determined by single crystal X ray diffraction. The crystal is monoclinic, space group P2 1/n , a=10.862(2), b=11.541(2), c=14\^994(3), β=108.41(3)°, V=1783(1), Z=4, D x =1.381 g/cm -3 , μ =0.3361 mm -1 , and F (000)=768. The results confirmed that the title compound belongs to type E of stereochemistry. The dihedral angle between triazole and 1,3,4 thiadiaole ring is 3° and the torsion angle between 1,3,4 thiadiazole and pyrazole ring is 134.0°.

The severity and cause of leaf spot disease of Pongamia pinnata L. and fungicidal control of the pathogen

A survey on the symptom and severity of the leaf spot disease of Pongamia pinnata L. was conducted in the nurseries of the Institute of Forestry and Environmental Sciences, University of Chittagong （IFESCU）, Bangladesh Forest Research Institute （BFRI） and Aronnak Nursery in Chittagong. The highest infection percentage and disease index were found in IFESCU nursery, followed by BFRI and the lowest was recorded in Aronnak nursery. The associated organism of leaf spot disease of P. pinnata was isolated from the diseased plant parts and the pathogenicity was established with the isolated fungus. Colletorichum gloeosprioides Penz was proved to be pathogenic. The inhibition of mycelial growth of C. gloeosporioides was observed and identified as suitable fungicides （Bavistin, Cupravite and Dithane M-45） and doses （0.05, 0.10, 0.50, 1.00, 1.50 and 2.00）. The lowest and highest mycelial growth were respectively found on Bavistin and on Cupravite at the concentration of 0.05 after 8th day of incubation. It indicates that out of the three tested fungicides, Bavistin showed most effective, followed by Diathane M-45, and Cupravite was ineffective for its very little inhibition on mycelial growth.

Comparison of Fungicidal Difference of Two Arylpyrazoles Based on the Crystal Structures, Density Functional Theory Calculation and Molecular Docking

Two arylpyrazoles I andⅡwere synthesized and characterized by NMR and single-crystal X-ray diffraction.Compound I displayed 71.4%fungicidal inhibition rate against Rhizoctonia solani at 0.1 ppm,better than the control pyraclostrobin,whereasⅡhad little activity.Their fungicidal difference was discussed from theoretic level based on the crystal structure,density functional theory(DFT)calculation and molecular docking.The B3 LYP/6-31G^**level was employed to explore the HOMO-LUMO energy gap and charge distribution.Molecular docking was performed on the probable target protein bc1-enzyme complex.DFT calculation and docking studies supported the in vitro findings.

Synthesis, Crystal Structure and Fungicidal Activity of Ethyl 2-(3-(4-Fluorobenzamido)phenyl)-4-((4-fluorobenzoyl)oxy)thiazole-5-carboxylate

The target compound,ethyl 2-(3-(4-fluorobenzamido)phenyl)-4-((4-fluorobenzoyl)oxy)thiazole-5-carboxylate,was synthesized by four-step procedures including N-protection,thionation,cyclization and acylation.Its structure was characterized by 1 H NMR,13C NMR,HRMS and single-crystal X-ray diffraction.The target compound crystallizes as monoclinic crystal system,space group C2/c with a=9.6097(19),b=14.246(3),c=33.070(7)A,V=4515.1(16)A3,Z=8.Dc=1.496 Mg/m3,F(000)=2096 andμ=0.203 mm-1.There are 21864 reflections measured(4.94≤2θ≤55.96°),of which 5357 were unique(Rint=0.1418)and used in all calculations.The final R=0.0581(I>2δ(I))and wR=0.1453(reflections).The target compound showed over 50%of growth inhibition against Physalospora piricola,Rhizoctonia cere al is and Sclerotinia sclerotiorum.

Synthesis and Fungicidal Activity of Chlorothalonil Derivatives

[Objective]The paper was to develop a novel fungicide with high efficacy and low toxicity.[Method]Chlorothalonil was used as the parent structure,and its 4-position substituent was converted to amino group.Totally 12 amide compounds not reported in the literature were designed and synthesized.Their structures were conformed by 1H NMR.[Result]The preliminary bioassay test showed that compounds JTCN-01,JTCN-05 and JTCN-07 had good control effect on corn rust at the concentration of 200 mg/L,and the control effect of compound JTCN-05 reached 95%.[Conclusion]Some chlorothalonil derivatives had the potential for further development.

Green Synthesis of Silver Nanoparticles with High Fungicidal Activity from Olive Seed Extract

Silver nanoparticles in the form of silver based chemicals trace back their origin to time immemorial since the dilute forms of silver nitrate were used in place of antibiotics before they dominated the field of medicine. But, it has now become necessary to explore the anti-microbial properties of silver based chemicals again due to the microbes gaining resistance against the wide range of present day antibiotics. The advancements in the field of medicine and technology started to coalesce to combat the adaptability of microbes as they successfully become tolerant to antibiotics and it manifested in the form a current technology, Nanomedicine. Nanomedicine deals about the medicines at a nano scale to rarefy the intensity of medicine to unaffected tissues and reduce the volume of medicine used. In the present context, our attempt is to develop potential anti-microbial particles in the form of silver nanoparticles by using the biological phenomena which we call Green synthesis an eco-friendly approach to conventional chemical synthesis. The enzymatic machinery of the olive seeds has been exploited to produce silver nanoparticles and test their efficacy as antifungal agents before we characterized their physical properties using UV-Vis, TEM, and FTIR analysis. The efficacy of these particles as antagonists on fungal pathogen Aspergillus niger a causative agent of Aspergillosis in human beings and is promising and they have a lot of scope for the purpose and hope the technology leads the next generation of anti-microbials.

Synthesis and fungicidal activity of some sulphide derivatives of O-phenyl-N-substituted phenylcarbamates

Monosulphides of O-phenyl-N-substituted phenylcar- bamates were prepared by the reaction between O- phenyl-N-substituted phenylcarbamates and sulph- ur dichloride while the corresponding disulphides were prepared by the reaction between O-phenyl-N- substituted phenylcarbamates and sulphur monoch- loride. The synthesized compounds were characte-rized by elemental analysis, thin layer chromatogra-phy (TLC), Fourier-transform infrared, 1H and 13C nuclear magnetic resonance spectroscopic techniques. In vitro fungicidal assay of these sulphides against Fusarium oxysporum, Aspergillus niger, Aspergillus flavus and Rhizopus stolonifer showed that they were more fungicidal than their parent carbamates. The synthesized sulphides were more active towards As-pergillus niger and Aspergillus flavus. There was little or no variations in the fungicidal activities of the synthesized monosulphides and disulphides of O-phen- yl-N-substituted phenyl carbamates.

Bactericidal and Fungicidal Efficacy of Chlorine Dioxide in Various Workspaces

Previously, we demonstrated the virucidal efficacy of low concentration chlorine dioxide (ClO2) gas in room settings. The purpose of these studies was to evaluate novel ClO2 formats as potential biocidal interventions for real world congregate settings and air systems. Three types of studies were conducted to determine the efficacy of ClO2 in reducing bacteria and mold in various workspaces: hard and soft surfaces (gymnasium & equipment), aerosol (in-room), and within a laboratory environment. The study demonstrated that ClO2 was highly effective against both bacteria and mold with reduction ranging from 85.0% - > 99.4% for bacteria and >99.4% for yeast and mold. Treatments on hard and soft surfaces (gymnasiums and sports equipment), reduced bacteria by an average of 90% - 95%. The following treatments were applied overnight: 1) hard surface spraying with dilute ClO2 solutions, 2) carpet and tumbling treatments with powdered ClO2 releasing impregnates, and 3) HVAC treatment and overall room deodorization with low dose ClO2 gas from controlled releasing sachets. The in-room study treating air with a ClO2 filtration media also indicated significant air and surface room efficacy, with an average of 94% reduction in bacteria after 24-hour, and 99.4% reduction in mold after 24-hours. In a related air study, a biological combination of Raoultella terrigena and Staphylococcus aureus was injected as a bio-aerosol into a 4-inch diameter pipe with air flowing at approximately 1200 ft/min. Dry ClO2 gas was introduced into the air flow to achieve an effective concentration of 5 or 10 ppmv. Air samples were collected at sampling ports downstream from the fan at 10, 22, 55 and 100 ft along the pipe and used to evaluate changes in airborne bacteria and mold. Testing was conducted in a laboratory setting at ambient conditions. The data showed ClO2 gas reduced viable organisms at both gas concentrations, and indicated that reductions were higher for 10 ppmv concentration, and longer pipe runs. In a final study, laboratory application of gaseous chlorine dioxide was tested. Low gas release filter testing demonstrated significant surface reductions of airborne bacteria with an overall average 99.4% reduction in the 24-hour testing period. Higher gas treatments of a class II biological cabinet reduced bacillus spores on steel coupons throughout cabinet by 6 log. ClO2 was effective as a bactericidal and fungicidal treatment providing significant reduction in both surface and air. Novel product delivery forms may be useful for rapidly disinfecting air and solid surfaces in complex congregate settings.

New Fungicidally Active Pyrazolyl-Substituted 1,3,4-Thiadiazole Compounds and Their Preparation

The potassium dithiocarbazate 2 was obtained through condensation of 5-pyrazole hydrazide 1 with carbon disulfide in ethanolic potassium hydroxide. and its cyclization gave 5-pyrazolyl-1,3,4-thiadiazole-2-thione 3 in concentrated sulfuric acid. Alkylation of 3 yielded 2-alkylthio-5-pyrazolyl-1,3,4-thiadiazole 4. The preliminary bioassay tests indicated that compounds 3 and 4 have fungicidal activity.

Synthesis, Crystal Structure and Fungicidal Activity of 2-Chloro-N-(o-tolylcarbamoyl)nicotinamide

The title compound 2-chloro-N-(o-tolylcarbamoyl)nicotinamide(C(14)H(12)ClN3O2) was synthesized, and its structure was confirmed by ~1H NMR, H RMS and X-ray diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 7.8356(7), b = 12.7949(8), c = 13.6326(10) ?, β = 91.929(7)°, V = 1365.97(18) ?~3, Z = 4, the final R = 0.0416 and wR = 0.0971 for 2467 observed reflections with I > 2σ(I). The preliminary biological test shows that the title compound has certain fungicidal activities.

Synthesis and Fungicidal Activity of （E）-5-[1-（2-Oxo- 1 -oxaspiro[4,5]dec/non-3-en-3-yl）ethylidene]-2- aminoimidazolin-4-one Derivatives

The novel fungicidal agents, （E）-5-[1-（2-oxo-l-oxaspiro[4,5]dec/non-3-en-3-yl）ethylidene]-2-aminoimidazolin- 4-one derivatives, were designed and synthesized in moderate to excellent yields in four steps using a-hydroxyketone and diketene as raw materials and characterized by HR-ESI-MS, 1H NMR and X-ray diffraction. The preliminary bioassay showed that some of these compounds, such as 5e, 6a, 6e, and 7h exhibit 87.8%, 91.3%, 89.9% and 87.8% inhibition rates against Sclerotinia scleotiorum, 3b, 3c, 4c and 7h exhibit 96.4%, 92.5%, 90.3% and 76.9% inhibition rates against Phytophthora capsici at the concentration of 50 μg/mL, respectively. These compounds exhibited significant fungicidal activities against S. scleotiorum and P. capsici with EC50 values of 2.56 --11.60 μg/mL, and compounds 6e and 7h exhibited weak inhibition against the spore germination of S. scleoti- orum, while the spore germination ofP. capsici was strongly inhibited by compound 7h solution. Scanning electron microscopy （SEM） and transmission electron microscopy （TEM） observation indicated that compound 7h had a significant impact on the structure and function of the hyphal cell wall ofP. capsici mycelium.

Design, Synthesis and Fungicidal Activity of Novel Strobilurin-l,2,4-Triazole Derivatives Containing Furan or Thiophene Rings

A series of strobilurin-l,2,4-triazole derivatives containing a furan or thiophen ring was designed andsynthesized. The structures of the compounds were characterized by 1H NMR, 13C NMR and HRMS spectra. Thebioassays indicated that the fungicidal activities of compounds 10b（EC50=14.82 mg/L） and 10c（EC50=18.72 mg/L）against Cercospora arachidicola Hori in vitro were much higher than that of Azoxystrobin as control（EC50=40.54mg/L） and the fungicidal activities of compounds 10u（EC50=8.66 rag/L） and 10n（EC50=9.89 rag/L） against Rhizotoniacerealis in vitro were higher than that of the same control（EC50=10.86 rag/L）. Compounds 10b, 10c, 1011 and 10kcould be considered as the leading compounds for further investigation.

Synthesis and Fungicidal Activity of Some Novel Thiazole Schiff Bases Derived from Benzo[d][1,3]dioxole

A series of novel thiazole Schiff base derivatives containing benzo[d][1,3]dioxole moiety was designed, synthesized and screened for their fungicidal activities. The preliminary results demonstrated that compounds 6p, 6q and 6r possessed potent activities against Phytophthora infestans, Pyricularia oryzae and Septoria tritici in vitro. Compounds 6d and 6r exhibited remarkable activities against Botrytis cinerea（whole plant） and Phytophthora in- festans（leaf disk） respectively in vivo, which were identified as the most promising candidates for further study and could be used as possible lead compounds for developing new fungicides.

Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China

Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.