Nano silver-encapsulation of Thymus daenensis and Anethum graveolens essential oils enhances antifungal potential against strawberry anthracnose

Nanotechnology is an eco-friendly strategy in managing plant diseases. In combination with existing practices nanotechnology can enhance the protection of agricultural products and food. For example, essential oils (EOs) of thyme (Thymus daenensis L.) and dill (Anethum graveolens L.) have an antimicrobial potential and this potential may be enhanced by certain nanoparticle systems. Here we demonstrate that encapsulating EOs of thyme and dill in silver nanoparticles increases their fungicidal activity against Colletotrichum nymphaeae, causing anthracnose in many horticultural crops. Using GC-MS analysis, we identified p-cymene, thymol, carvacrol and (E)-caryophyllene as the main EOs of thyme and limonene, cis-dihydrocarvone, cyclohexanon, and carvone as the main EOs of dill. When the EOs of the two sources were encapsulated in silver nanoparticles, synergistic effects against C. nymphaeae were observed, resulting in more than 80% inhibition of mycelium growth of C. nymphaeae. Moreover, conidia germination was suppressed by nano-encapsulated EOs. We also observed considerable morphological changes in the fungal hyphae when nano-encapsulated EOs were applied. Our study demonstrates the potential of encapsulated EOs in controlling pathogens that can be very applicable as antifungal agents.</p

Complexation of 1,3-Dimorpholinopropane with Hg(II) and Zn(II) Salts: Syntheses, Crystal Structures and Antibacterial Studies

WOS: 000359393900002Two Hg(II) (1) and Zn(II) (2) complexes with general formulation M(DMP)Cl-2 where DMP=1,3-dimorpholinopropane were synthesized and structurally characterized by physicochemical methods and single crystal X-ray diffraction. An X-ray structural analysis shows that in both complexes Hg and Zn are coordinated by two nitrogen and two chlorine atoms in a form of distorted tetrahedron. The ligand and related complexes have antibacterial activity against three Gram-positive bacteria (S. epidermidis ATCC 25923, E. faecalis ATCC 23212 and S. epidermidis ATCC 34384), and also against the three Gram-negative bacteria (E. coli ATCC 25922, P. aeruginosa ATCC 27853 and K. pneumonia ATCC 70063). The results revealed that in some cases the antibacterial activity of Hg(II) complex exceeded the one of sulfisoxazole used as a standard. CCDC: 957542, 1; 957846, 2.Czech Science FoundationGrant Agency of the Czech Republic [14-03276S]Crystallography part was supported by the project (No.14-03276S) of the Czech Science Foundation

Synthesis, characterization and crystal structures of new Zinc(II) and Nickel(II) complexes containing morpholine moiety and their antibacterial studies

WOS: 000347416400013The ligand 1,2-dimorpholinoethane (DME) was used to prepare Zn(II) and Ni(II) complexes of the general formulation MLX2 (L = DME, X = Cl or NO3). Zinc(II) complex exhibits spectral properties indicative of a distorted tetrahedral geometry, with DME coordinating through two nitrogen atoms and two chlorides completing the tetrahedron. This is in contrast to the six-coordinated, distorted octahedral geometry exhibited by nickel(II) complex of DME when NO3 was used as counter ions. The X-ray diffraction confirms the structures of two complexes and shows that the ligand coordinates through two nitrogen atoms while the two ether linkages are not involved in complexation, which would have been the case if the morpholine rings were in the boat form. The ligand and related complexes have antibacterial activity against the five Gram-positive bacteria: Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Streptococcus pyogenes and also against the three Gram-negative bacteria: Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442 and Klebsiella pneumonia ATCC 70063. The results showed that in some cases the antibacterial activity of the complexes exceeded the one of sulfisoxazole used as a standard.Ilam University, Ilam, IranFinancial support for this work by the Ilam University, Ilam, Iran is gratefully acknowledged. Crystallography part was supported by the project Praemium Academiae of the Academy of Sciences of the Czech Republic