Fungicidal and spectral studies of some triphenyltin compounds

In the interest of developing a more effective fungicide to combat Dutch elm disease, our laboratories have synthesized several triphenyltin carboxylates and some 1:1 addition compounds of triphenyltin chloride using 2,3-disubstituted thiazolidin-4-ones as the ligand and screened them in vitro against Ceratocystis ulmi, the causative agent of Dutch elm disease, using a shake culture method. Elemental analyses and spectroscopic data indicate that the structures of the carboxy- lates in the solid state are monomeric with a tetrahedral tin atom with the exception of the furan-2-carboxylic acid derivative, which was found to be polymeric. The triphenyltin chloride adducts are trigonal-bipyramidal with the three phenyl groups in the equatorial plane. Far-infrared data indicate that the three phenyl groups are not co-planar. Screening results for both series of organotins indicate that these two classes of compounds are effective inhibitors of Ceratocystis ulmi, with the adducts having a higher activity. The furan-2-carboxylic acid derivative has a markedly decreased activity compared with the other carboxylates and this is attributed to its polymeric structure. © 1998 John Wiley & Sons, Ltd.     

Metabolite mass spectrometry profiling of cacao genotypes reveals contrasting resistances to Ceratocystis cacaofunesta phytopathogen

Ceratocystis wilt is a lethal disease of cacao, and the search for resistant genotypes may provide the best way to deal with the disease. Resistance or susceptibility behavior of some cacao genotypes when infected by Ceratocystis cacaofunesta is not yet understood. Herein, we report an LC-MS metabolomic screening analysis based on high-resolution MS to obtain comprehensive metabolic profile associated with multivariate data analysis of PLS-DA, which was effective to classify CCN-51 and TSH-1188 as resistant genotypes to C. cacaofunesta fungus, while CEPEC2002 was classified as a susceptible one. Using reversed-phase LC method, electrospray interface, and high-resolution tandem MS by the quadrupole-TOF analyzer, the typical profiles of metabolites, such as phenylpropanoids, flavonoids, lipids, alkaloids, and amino acids, were obtained. Untargeted metabolite profiles were used to construct discriminant analysis by partial least squares (PLS-DA)-derived loading plots, which placed the cacao genotypes into two major clusters related to susceptible or resistant groups. Linolenic, linoleic, oleic, stearic, arachidonic, and asiatic acids were annotated metabolites of infected, susceptible, and resistant genotypes, while methyl jasmonate, jasmonic acid, hydroxylated jasmonic acid, caffeine, and theobromine were annotated as constituents of the resistant genotypes. Trends of these typical metabolites levels revealed that CCN51 is susceptible, CEPEC2002 is moderately susceptible, and TSH1188 is resistant to C. cacaofunesta. Therefore, profiles of major metabolites as screened by LC-MS offer an efficient tool to reveal the level of resistance of cacao genotypes to C. cacaofunesta present in any farm around the world.     

The synthesis,structural characterization and biocidal properties of some triorganotin(IV) esters of N-arylidene-ω-amino acids.

The methods of synthesis, elemental analysis, IR and NMR spectroscopic data and fungicidal activity against Ceratocystis ulmi are reported for a series of triorganotin esters of N-arylidene-ω-amino acids of general formula R₃SnOCO(CH₂)_nN = CHAr (R = Ph, n-Bu; Ar = 2-HOC₆H₄, 2-HOC₁₀H₆; n = 1, 2, 3 and 5). The crystal structures for two of the compounds, tributyltin N-2-hydroxynaphthalidene glycinate ( 1 ) and tributyltin N-2-hydroxynaphthalidene-β-alaninate ( 2 ), have been determined. Although both of these compounds have a trans-R₃SnO₂ structure, in compound 1 the carboxylate group is monodentate and the fifth coordination position around the tin atom is taken up by a coordinated phenolic group, whereas in 2 the carboxylate group is bridging. These two examples thus correspond to the two different structures reported for trans-R₃SnO₂ complexes. Both compounds were found to be active against Ceratocystis ulmi, but there was no significant difference in their levels of biological activity against this particular fungus. Apart from compound 1 , the other tributyltin compounds reported are believed to adopt the carboxylate bridging mode shown by compound ( 2 ). Crystal data: for 1 , crystals monoclinic, space group P 2₁/ c , a = 12.9435(11) Å, b = 13.5769(10) Å, c = 15.7715(12) Å, β = 108.919(6)°, Z = 4, R _f = 0.046 and R _w = 0.058 for 1448 significant reflections; for 2 , crystals monoclinic, space group C 2/ c , a = 24.588(14) Å, b = 9.733(3) Å, c = 27.611(12) Å, β = 113.49(4)°, Z = 8, R _f = 0.053 and R _w = 0.069 for 3822 significant reflections. © 1998 John Wiley & Sons, Ltd.     

Structure–Activity relationships of effect of aryltin compounds on Ceratocystis ulmi

The effect of aryltin compounds (Ar₄Sn and Ar₃SnCl) on the growth of Ceratocystis ulmi, the causative agent of Dutch elm disease, was studied in shake culture. In all cases, the triaryltins were more effective than the tetra-aryltins as inhibitors of C. ulmi in vitro. Furthermore, substitution on the phenyl ring at the meta- and para- positions in the triaryltins did not have a major effect on the biocidal activity for the substituted triaryltins. Quantitative structure–activity relationships (QSARs) gave support to the idea that the species responsible for the inhibition of the fungus is the triaryltin cation. The QSARs further suggest that the interaction of the triaryltin cation with the fungal cell wall of C. ulmi is by a non-specific mechanism.     

Triphenyltin Esters of N-(2-Carboxybenzylidene)anilines: Synthesis,Spectroscopic Characterization,X-ray Structure Analysis and Fungicidal Activity

Four triphenyltin carboxylates formulated as o- Ph₃SnOCOC₆H₄CH=N–Ar (Ar=C₆H₅; p -CH₃C₆H₄; o -CH₃C₆H₄; o -HOC₆H₄) were prepared and spectroscopically characterized. The crystal structure of o -Ph₃SnOCOC₆ H₄CH=NC₆H₅ indicates that the tin atom, in each of the two molecules comprising the asymmetric unit, exists in a distorted tetrahedral geometry owing to an intramolecular acyl O. . .Sn contact. These new triphenyltin carboxylates display marked toxicity against the fungus Ceratocystis ulmi .     

Fungicidal Activity of Some Organotin Compounds against Ceratocystis ulmi

Three series of organotin compounds were screened in vitro against Ceratocystis ulmi , the causative agent of Dutch elm disease. The series that were most active against this deadly fungus were those that contained the triphenyltin moiety. In addition, the fungicidal activity of the triphenyltin compounds were found to be independent of the anionic group attached to the tin atom. However, there was a marked increase in the activity of the triphenyltins when a biologically active group which did not dissociate upon dissolution was incorporated into the overall molecule.     

Tolerance of aggressive and non-aggressive isolates of Ceratocystis ulmi to organotin fungicides

The effect of triorganotin compounds, R₃SnX, on the growth of three wild strains of Ceratocystis ulmi (C. ulmi) fungus, two aggressive and one non-aggressive strains, was evaluated in shake culture. In all cases, the triphenyltins were the more effective organotins for the inhibition of C. ulmi in vitro. The anionic group, X, did not have a significant role in the inhibition, suggesting that the species involved in the inhibition is the triphenyltin moiety (Ph₃Sn⁺) or the hydrated triphenyltin moiety (Ph₃Sn(H₂O)⁺₂). It is further suggested that the triphenyltin species Ph₃SnOH and Ph₃SnOAc are the preferred compounds for the control of Dutch elm disease. The tolerance of aggressive isolates to fungitoxins appears to depend more on the nature of the fungicide than on the type of fungus.