- Expedient discovery for novel antifungal leads: 1,3,4-Oxadiazole derivatives bearing a quinazolin-4(3H)-one fragment
-
Developing novel fungicide candidates are intensively promoted by the rapid emergences of resistant fungi that outbreak on agricultural production. Aiming to discovery novel antifungal leads, a series of 1,3,4-oxadiazole derivatives bearing a quinazolin-4(3H)-one fragment were constructed for evaluating their inhibition effects against phytopathogenic fungi in vitro and in vivo. Systematically structural optimizations generated the bioactive molecule I32 that was identified as a promising inhibitor against Rhizoctonia solani with the in vivo preventative effect of 58.63% at 200 μg/mL. The observations that were captured by scanning electron microscopy and transmission electron microscopy demonstrated that the bioactive molecule I32 could induce the sprawling growth of hyphae, the local shrinkage and rupture on hyphal surfaces, the extreme swelling of vacuoles, the striking distortions on cell walls, and the reduction of mitochondria numbers. The above results provided an indispensable complement for the discovery of antifungal lead bearing a quinazolin-4(3H)-one and 1,3,4-oxadiazole fragment.
- Chai, Jianqi,Chen, Min,Jin, Fei,Kong, Xiangyi,Wang, Xiaobin,Xue, Wei,Yang, Chunlong
-
-
- Synthesis and larvicidal activity of 1,3,4-oxadiazole derivatives containing a 3-chloropyridin-2-yl-1H-pyrazole scaffold
-
Abstract: A new series of 1,3,4-oxadiazole derivatives with a 3-chloropyridin-2-yl-1H-pyrazole moiety was designed, synthesized, and characterized. The results of bioassay against Helicoverpa armigera and Plutella xylostella indicated that some of the synthesized compounds showed remarkable larvicidal activity. In particular, the LC50 values of the most active compounds against P. xylostella were 46.5, 23.9, and 13.9?mg/dm3, and against Helicoverpa armigera were 88.3 and 69.5?mg/dm3, the latter being slightly better than commercial chlorpyrifos (LC50 103.77?mg/dm3). Preliminary SAR was also discussed. Graphical abstract: [Figure not available: see fulltext.].
- Wang, Yanyan,Lu, Xiumian,Shi, Jun,Xu, Jiahong,Wang, Fenghua,Yang, Xiao,Yu, Gang,Liu, Zhiqian,Li, Chuanhui,Dai, Ali,Zhao, Yonghui,Wu, Jian
-
p. 611 - 623
(2018/01/17)
-
- Synthesis, Nematicidal Activity, and 3D-QSAR of Novel 1,3,4-Oxadiazole/ Thiadiazole Thioether Derivatives
-
Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchulus semipenetrans in vitro and in vivo. Compounds 20, 21, 35 and 39 showed excellent lethal activities after treatment for 48?h in vitro, with LC50 values of 13.4?±?1.8, 11.7?±?2.5, 13.7?±?2.4 and 13.3?±?1.1?mg·L–1, respectively, which were obviously superior to fosthiazate (49.1?±?2.8?mg·L–1) and avermectin (26.6?±?2.3?mg·L–1). Compound 21 can effectively control the citrus nematode disease caused by T. semipenetrans at 200?mg·L–1 in vivo with (68?±?3)% inhibitory effect, which was even better than that of avermectin ((63?±?2)%). The CoMFA and CoMSIA models of three-dimensional quantitative structure-activity relationships (3D-QSARs) were established. The compound 33 was designed based on the 3D-QSAR models with more vigorous nematicidal activities in vitro (LC50?=?9.8?±?1.4?mg·L–1) and in vivo ((70?±?5)%). These results demonstrated that compound 33 can be considered as a potential nematicide.
- Chen, Jixiang,Gan, Xiuhai,Yi, Chongfen,Wang, Shaobo,Yang, Yuyuan,He, Fangcheng,Hu, Deyu,Song, Baoan
-
p. 939 - 944
(2018/09/22)
-
- 2,5-substituent-1,3,4-oxadiazole (thiadiazole) thioether derivatives as well as preparation method and application thereof
-
The invention discloses 2,5-substituent-1,3,4-oxadiazole (thiadiazole) thioether derivatives as well as a preparation method and an application thereof. The 2,5-substituent-1,3,4-oxadiazole (thiadiazole) thioether derivatives have the general formula (I) shown in the following specification, wherein R1 represents as 4-chlorphenyl, 4-fluorophenyl, 4-methylphenyl, 4-methoxyphenyl, 4-nitrophenyl, 4-cyano-3,5-difluorophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxyphenyl, 4-t-butylphenyl, 2-fluorophenyl and other substituents; R2 represents methyl, ethyl, 4-chlorobenzyl, 2,4-dichlorobenzyl, 4-trifluoromethoxy, benzyl, 4-fluorobenzyl, 4-chlorobenzyl and other substituents; X represents O or S. The compound can be used as a pesticide for killing crop nematode and inhibiting bacterial diseases of crops.
- -
-
Paragraph 0021
(2017/04/03)
-
- Synthesis and antibacterial evaluation of new sulfone derivatives containing 2-aroxymethyl-1,3,4-oxadiazole/thiadiazole moiety
-
Sulfones are one of the most important classes of agricultural fungicides. To discover new lead compounds with high antibacterial activity, a series of new sulfone derivatives were designed and synthesized by introducing the aroxymethyl moiety into the scaffold of 1,3,4-oxadiazole/thiadiazole sulfones. Antibacterial activities against three phytopathogens (Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, Xanthomonas axonopodis pv. citri.) were assayed in vitro. As compared to the control of commercial fungicides and some reported sulfone fungicides, seven compounds 5I-1-5I-7 exerted remarkably higher activities with EC50 values ranging from 0.45-1.86 μg/mL against X. oryzae and 1.97-20.15 μg/mL against R. solanacearum. Exhilaratingly, 5I-1, 5I-2 and 5I-4 displayed significant in vivo activity against X. oryzae with protective effect of 90.4%, 77.7%, and 81.1% at 200 μg/mL, respectively, much higher than that exhibited by Bismerthiazol (25.6%) and Thiadiazole-copper (32.0%). And the differential phytotoxicity of active derivatives was preliminarily checked. The results demonstrated that derivative of 2-aroxymethyl-1,3,4-oxadiazole/thiadiazole sulfone can serve as potential alternative bactericides for the management of plant bacterial diseases.
- Su, Shihu,Zhou, Xia,Liao, Guoping,Qi, Puying,Jin, Linhong
-
-
- Synthesis, Characterization and Properties of Novel Coumarin Derivatives and Their Europium Complexes
-
Seven novel coumarin derivatives derived from salicylaldehyde and phenol were synthesized and characterized by 1H NMR and 13C NMR spectra, mass spectra, infrared spectra and elemental analysis. Their corresponding Eu(III) complexes having general formula EuL1-7(NO3)3·2H2O were successfully prepared and characterized by elemental analysis, EDTA titrimetric, molar conductivity, UV-Vis, FT-IR and thermal performance studies. The luminescence properties, fluorescence quantum yields and the electrochemical properties of the title complexes were investigated. The results showed that the title complexes exhibited characteristic emissions of europium ions and possessed relatively good fluorescence quantum yields. The luminescence intensity of the complex with bromine-substituted group is the strongest among all the title complexes. The introduction of electron-withdrawing groups can increase the luminescence properties and fluorescence quantum yields, decrease the HOMO and LUMO energy levels of the title europium complexes, but electron-withdrawing group conversely. And these title complexes may possibly be useful for studying in luminescent materials field.
- Yan, Dong,Li, Dong,Cheng, Guang,Yang, Zehui,Shi, Ling,Guo, Dongcai
-
p. 849 - 859
(2015/08/24)
-
- Synthesis and luminescence properties of pyrazolone derivatives and their terbium complexes
-
Seven novel pyrazolone derivatives were synthesized and characterized by 1H NMR and 13C NMR spectra, mass spectra, infrared spectra and elemental analysis. Their terbium complexes were prepared and characterized by elemental analysis, EDTA titrimetric analysis, UV/vis spectra, infrared spectra and molar conductivity, as well as thermal analysis. The fluorescence properties and fluorescence quantum yields of the complexes were investigated at room temperature. The results indicated that pyrazolone derivatives had good energy-transfer efficiency for the terbium ion. All the terbium complexes emitted green fluorescence characteristic of terbium ions, possessed strong fluorescence intensity, and showed relatively high fluorescence quantum yields. Cyclic voltammograms of the terbium complexes were studied and the highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) energy levels of these complexes were estimated.
- Xiao, Haihua,Jiang, Xi,Li, Dong,Wu, Limin,Zhang, Wu,Guo, Dongcai
-
p. 677 - 685
(2015/12/04)
-
- Synthesis of oxadiazole-morpholine derivatives and manifestation of the repressed CD31 Microvessel Density (MVD) as tumoral angiogenic parameters in Dalton's Lymphoma
-
A series of oxadiazole derivatives possessing morpholine 6a-l were synthesized by nucleophilic substitution reaction of key intermediates [1,3,4]-oxadiazole-2-thiol derivatives 5a-l with 4-(2-chloroethyl) morpholine. Compounds 6a-l were evaluated for their in vitro and in vivo antitumor potential in Dalton's Lymphoma Ascites (DLA) tumor cells. Among 6a-l series, compound 6a with concentration ～8.5 μM have shown extensive cytotoxicity in vitro and 85% reduction in tumor volume in vivo, attributing an excellent anti-proliferative capability towards the cancer cells. Compound 6a has extensively inhibited the Microvessel Density (MVD) or tumoral neovasculature which was evident from the CD31 immuno staining and peritoneal H&E staining. The major reason for the antiproliferative activity of compound 6a was due to the repression of tumor vasculature.
- Al-Ghorbani, Mohammed,Vigneshwaran,Ranganatha, V. Lakshmi,Prabhakar,Khanum, Shaukath Ara
-
p. 136 - 146
(2015/06/02)
-
- Synthesis and xanthine oxidase inhibitory activity of 7-methyl-2- (phenoxymethyl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives
-
An elevated level of blood uric acid (hyperuricemia) is the underlying cause of gout. Xanthine oxidase is the key enzyme that catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Allopurinol, a widely used xanthine oxidase inhibitor is the most commonly used drug to treat gout. However, a small but significant portion of the population suffers from adverse effects of allopurinol that includes gastrointestinal upset, skin rashes and hypersensitivity reactions. Moreover, an elevated level of uric acid is considered as an independent risk factor for cardiovascular diseases. Therefore use of allopurinol-like drugs with minimum side effects is the ideal drug of choice against gout. In this study, we report the synthesis of a series of pyrimidin-5-one analogues as effective and a new class of xanthine oxidase inhibitors. All the synthesized pyrimidin-5-one analogues are characterized by spectroscopic techniques and elemental analysis. Four (6a, 6b, 6d and 6f) out of 20 synthesized molecules in this class showed good inhibition against three different sources of xanthine oxidase, which were more potent than allopurinol based on their respective IC50 values. Molecular modeling and docking studies revealed that the molecule 6a has very good interactions with the Molybdenum-Oxygen-Sulfur (MOS) complex a key component in xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious, than allopurinol, to treat gout and possibly against cardiovascular diseases.
- Sathisha,Khanum, Shaukath A.,Chandra, J.N. Narendra Sharath,Ayisha,Balaji,Marathe, Gopal K.,Gopal, Shubha,Rangappa
-
p. 211 - 220
(2011/03/17)
-
- Syntheses and insecticidal activities of novel 2-fluorophenyl-5-aryl/cyclopropyl-1,3,4-oxadiazoles
-
Two 2-fluorophenyl-5-substitued cyclopropyl-1,3,4-oxadiazoles (IIIa-b) with cis/trans isomers were synthesized from the corresponding hydrazide (Ia) and aroyl chlorides by two-step reactions. Six asymmetrical 2-(2,4-dichloro-5-fluorophenyl)-5-aryl-1,3,4-oxadiazoles (IIIc-h) were obtained by one step reaction of 2,4-dichloro-5-fluorobenzoic acid hydrazide (Ic) with the corresponding aromatic carboxylic acid in the presence of phosphorus oxychloride under reflux. However, the similar reaction of 4-fluorophenoxyacetic acid hydrazide (Ib) with 2,4-dichloro-5-fluorobenzoic acid failed to yield the desired asymmetrical 2-(2,4-dichloro-5-fluorophenyl)-5-(fluorophenoxymethyl)-1,3,4-oxadiazole, and the resulting product was characterized as symmetrical 2,5-bis(2,4-dichloro-5-fluorophenyl)-1,3,4-oxadiazole (DCFPO). A possible reaction mechanism is suggested. Insecticidal activities of these nine new compounds against armyworms (Pseudaletia separata Walker) were determined.
- Shi, Wei,Qian, Xuhong,Song, Gonghua,Zhang, Rong,Li, Rongpo
-
p. 173 - 179
(2007/10/03)
-
