Synthesis and fungicidal activity of phenylhydrazone derivatives containing two carbonic acid ester groups

Assessment of soil yeasts Papiliotrema laurentii S-08 and Saitozyma podzolica S-77 for plant growth promotion and biocontrol of Fusarium wilt of brinjal

AIM

This study aimed to determine the efficacy of the soil yeasts Papiliotrema laurentii S-08 and Saitozyma podzolica S-77 for plant growth promotion (PGP) and biocontrol of wilt disease in brinjal plants while applying yeasts individually or as a consortium in pot experiments.

METHODS AND RESULTS

The yeasts were tested for various PGP characteristics and antagonistic activity against the phytopathogen Fusarium oxysporum f. sp. melongenae. Both the yeast isolates demonstrated some PGP attributes as well as inhibited the growth of the phytopathogen. A gas chromatography-mass spectrometry analysis of the yeast metabolites revealed the presence of several antifungal compounds. The pot experiment performed under nursery conditions showed that applying these yeasts, individually or in consortium, decreased the percent disease incidence in brinjal seedlings while significantly enhancing their growth parameters.

CONCLUSION

Papiliotrema laurentii S-08 and S. podzolica S-77 can be used in brinjal plants as plant growth promoters and also as biocontrol agents against the brinjal wilt disease.

I2/DMSO-Promoted Synthesis of Diaryl Sulfide- and Selenide-Embedded Arylhydrazones

Functionalization and derivatization of arylhydrazones are important in pharmaceutical, medicinal, material, and coordination chemistry. In this regard, a facile I₂/DMSO-promoted cross-dehydrogenative coupling (CDC) for direct sulfenylation and selenylation of arylhydrazones has been accomplished utilizing arylthiols/arylselenols at 80 °C. This method provides a metal-free benign route for the synthesis of a variety of arylhydrazones embedded with diverse diaryl sulfide and selenide moieties in good to excellent yield. In this reaction, molecular I₂ acts as a catalyst, and DMSO is utilized as a mild oxidant as well as solvent to produce several sulfenyl and selenyl arylhydrazones through a CDC-mediated catalytic cycle.

Novel carboxylated pyrroline-2-one derivatives bearing a phenylhydrazine moiety: Design, synthesis, antifungal evaluation and 3D-QSAR analysis

Aiming to discover novel high-efficient antifungal leads that possess an innovative action mechanism, twenty-three carboxylated pyrroline-2-one derivatives, bearing a phenylhydrazine moiety, were rationally designed and firstly prepared in this letter. The in vitro bioassays showed that most of the compounds possessed excellent antifungal effects with the EC₅₀ values of less than 1 μg/mL against the phytopathogenic fungi Fusarium graminearum (Fg), Botrytis cinerea (Bc), Rhizoctonia solani (Rs) and Colletotrichum capsici (Cc). The further bioassays showed that the compound 6u showed the comparable in vivo control effect with carbendazim against fusarium head blight and rice sheath blight. The 3D-QSAR model revealed the pivotal effects of a bulky electron-donating group at the 1-position of pyrrole ring, a bulky electron-withdrawing group at the 4-position of phenyl ring and a small alkyl at the carbonate group on the anti-Rs activities of target compounds. The abnormal mycelial morphology and delayed spore germination were observed in the treatments of compound 6u. Given the excellent and broad-spectrum antifungal effects the target compounds have, we unfeignedly anticipated that the above finding could motivate the discovery of high-efficient antifungal leads, which might possess an innovative action mechanism against phytopathogenic fungi.

Novel 5-chloro-pyrazole derivatives containing a phenylhydrazone moiety as potent antifungal agents: synthesis, crystal structure, biological evaluation and a 3D-QSAR study

Novel 5-chloro-pyrazole derivatives containing a phenylhydrazone moiety were designed and synthesized. Some of the target compounds showed potent fungicidal activity. A 3D-QSAR study provides information for structural optimization.

Design, synthesis, antifungal activity and 3D-QSAR study of novel pyrazole carboxamide and niacinamide derivatives containing benzimidazole moiety

The synthesized pyrazole carboxamide and niacinamide derivatives containing a benzimidazole moiety showed effective inhibition of the fungus B. cinereal growth. The 3D-QSAR model was built and revealed fine predictive ability.

Design and synthesis of novel 3-(thiophen-2-yl)-1,5-dihydro-2H-pyrrol-2-one derivatives bearing a hydrazone moiety as potential fungicides

BACKGROUND

Tetramic acid, thiophene and hydrazone derivatives were found to exhibit favorable antifungal activity. Aiming to discover novel template molecules with potent antifungal activity, a series of novel 3-(thiophen-2-yl)-1,5-dihydro-2H-pyrrol-2-one derivatives containing a hydrazone group were designed, synthesized, and evaluated for their antifungal activity.

RESULTS

The structures of 3-(thiophen-2-yl)-1,5-dihydro-2H-pyrrol-2-one derivatives bearing a hydrazone group were confirmed by FT-IR, 1H NMR, 13C NMR, 1H-1H NOESY, EI-MS and elemental analysis. Antifungal assays indicated that some title compounds exhibited antifungal activity against Fusarium graminearum (Fg), Rhizoctorzia solani (Rs), Botrytis cinerea (Bc) and Colletotrichum capsici (Cc) in vitro. Strikingly, the EC50 value of 5e against Rs was 1.26 µg/mL, which is better than that of drazoxolon (1.77 µg/mL). Meanwhile, title compounds 5b, 5d, 5e-5g, 5n-5q and 5t exhibited remarkable anti-Cc activity, with corresponding EC50 values of 7.65, 9.97, 6.04, 6.66, 7.84, 7.59, 9.47, 5.52, 6.41 and 7.53 µg/mL, respectively, which are better than that of drazoxolon (19.46 µg/mL).

CONCLUSIONS

A series of 3-(thiophen-2-yl)-1,5-dihydro-2H-pyrrol-2-one derivatives bearing a hydrazone group were designed, synthesized and evaluated for their antifungal activity against Fg, Rs, Bc and Cc. Bioassays indicated that some target compounds exhibited obvious antifungal activity against the above tested fungi. These results provide a significant basis for the further structural optimization of tetramic acid derivatives as potential fungicides.