Deoxygenation of Methyl Laurate as a Model Compound to Hydrocarbons on Ni₂P/SiO₂, Ni₂P/MCM-41, and Ni₂P/SBA-15 Catalysts with Different Dispersions

The deoxygenation of methyl laurate as a model compound to diesel-like hydrocarbons was performed on Ni₂P/SiO₂, Ni₂P/MCM-41, and Ni₂P/SBA-15 catalysts. The effect of Ni₂P dispersion on the catalyst structure and performance was investigated. The average Ni₂P crystallite sizes varying from 3 to 12 nm were obtained. In correlation with the Ni/P ratio, the catalyst acid amount was mainly determined by the surplus P species. The deoxygenation was tested at 300–340 °C, 2.0 MPa, weight hourly space velocity of 10 h^–1, and H₂/methyl laurate ratio of 50. For different catalysts, the conversion of methyl laurate followed the different sequence from the turnover frequency (TOF). The TOF increased with the Ni₂P crystallite size. The lower TOF on smaller crystallites can be attributed to the stronger interaction between Ni and P. Both hydrodeoxygenation and decarbonylation pathways occurred on the Ni₂P catalysts. As indicated by the ratio between <i>n</i>-undecane (<i>n</i>-C₁₁) and <i>n</i>-dodecane (<i>n</i>-C₁₂) being larger than 1.0, the main deoxygenation pathway was decarbonylation. We suggested that the deoxygenation pathway was affected by Brönsted acidity and Ni₂P crystallite size (i.e., the interaction between the Ni and P atoms). The Brönsted acid sites because of P–OH groups and the Ni sites having less interaction with P favored the decarbonylation pathway. With an increasing reaction temperature, the conversion, the selectivity to <i>n</i>-C₁₁ and <i>n</i>-C₁₂, and the <i>n</i>-C₁₁/<i>n</i>-C₁₂ ratio increased. At 340 °C, the conversion and the selectivity to <i>n</i>-C₁₁ and <i>n</i>-C₁₂ on all Ni₂P catalysts exceeded 97 and 99%, respectively

Hydroconversion of Methyl Laurate as a Model Compound to Hydrocarbons on Bifunctional Ni₂P/SAPO-11: Simultaneous Comparison with the Performance of Ni/SAPO-11

The bifunctional Ni₂P/SAPO-11 was tested for the hydroconversion (involving deoxygenation and hydroisomerization) of methyl laurate as a model compound to hydrocarbons. The influences of reaction conditions, catalyst stability, and catalyst deactivation were investigated. For comparison, the performance of Ni/SAPO-11 was also examined. The result shows that the increase of temperature and the deceases of weight hourly space velocity (WHSV) and H₂ pressure favored the conversion of methyl laurate meanwhile promoted the decarbonylation and hydroisomerization as well as cracking reactions. Apart from the Ni sites that were dominating for deoxygenation, the acid sites also affected the deoxygenation pathway. Due to more medium strength acid sites, Ni/SAPO-11 gave higher selectivity to isoalkanes and more preferentially catalyzed the hydrodeoxygenation pathway to produce the C12 hydrocarbons than Ni₂P/SAPO-11. During the test for 101 h, Ni₂P/SAPO-11 exhibited greatly superior stability to Ni/SAPO-11 for the deoxygenation of methyl laurate, while both Ni₂P/SAPO-11 and Ni/SAPO-11 were deactivated for the hydroisomerization. Under the condition of 360 °C, 3.0 MPa, WHSV of 2 h^–1, and H₂/methyl laurate molar ratio of 25, the conversion of methyl laurate was close to 100% and the total selectivity to isoundecane and isododecane decreased from 36.9% to 28.6% on Ni₂P/SAPO-11. To explore the catalyst deactivation, the fresh and the used catalysts were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy, and N₂ adsorption–desorption. The sintering of Ni particles and carbonaceous deposit contribute to inferior stability of Ni/SAPO-11 for both deoxygenation and hydroisomerization, while no obvious sintering of Ni₂P particles took place and the carbonaceous deposit mainly led to the loss of the activity for hydroisomerization on Ni₂P/SAPO-11. We propose that carbonaceous deposit mostly formed on the acid sites that are indispensible for hydroisomerization

Synthesis, Anti-Tomato Spotted Wilt Virus Activities, and Interaction Mechanisms of Novel Dithioacetal Derivatives Containing a 4(3<i>H</i>)‑Quinazolinone Pyrimidine Ring

A series of unreported novel dithioacetal derivatives containing a 4­(3H)-quinazolinone pyrimidine ring were synthesized, and their antiviral activities were evaluated against tomato spotted wilt virus (TSWV). A three-dimensional quantitative structure–activity relationship (3D-QSAR) analysis was established, and compound D32 was designed and synthesized according to the analysis results of the CoMFA and CoMSIA models. The bioassay results showed that compound D32 exhibited excellent inactivation activity against TSWV, with EC50 values of 144 μg/mL, which was better than those of ningnanmycin (149 μg/mL) and the lead compound xiangcaoliusuobingmi (525 μg/mL). The binding ability of compound D32 to TSWV CP was tested by microscale thermophoresis (MST), and the binding constant value was 4.4 μM, which was better than those of ningnanmycin (6.2 μM) and xiangcaoliusuobingmi (59.1 μM). Therefore, this study indicates that novel dithioacetal derivatives containing a 4­(3H)-quinazolinone pyrimidine ring may be applied as new antiviral agents

First Report on Anti-TSWV Activities of Quinazolinone Derivatives Containing a Dithioacetal Moiety

Tomato spotted wilt virus (TSWV) is a plant virus with strong infectivity and destructive power. Given the lack of effective control agents, TSWV causes significant economic damage to several vegetables and ornamental plants worldwide. In this study, we designed and synthesized a series of novel quinazolinone derivatives containing a dithioacetal moiety and evaluated their antiviral activity in vitro and in vivo against TSWV. Some candidate compounds showed good anti-TSWV activity. Compound 6n shows excellent anti-TSWV activity in vivo, and the EC50 value is 188 mg/L, which is notably better than that observed for ribavirin (642 mg/L), xiangcaoliusuobingmi (420 mg/L), and ningnanmycin (257 mg/L). In addition, compound 6n interacts with TSWV coat protein at sites ARG94 and ARG95 forming four π-alkyl interactions. Compound 6n (9.4 μM) shows a better binding affinity with TSWV coat protein than ribavirin (67.8 μM), xiangcaoliusuobingmi (33.8 μM), and ningnanmycin (24.3 μM). Therefore, compound 6n can serve as a lead compound for the discovery of new antiviral agents for the management of TSWV

Design, Synthesis, Nematicidal Activity, and Mechanism of Novel Amide Derivatives Containing an 1,2,4-Oxadiazole Moiety

To discover new nematicides, a series of novel amide derivatives containing 1,2,4-oxadiazole were designed and synthesized. Several compounds showed excellent nematicidal activity. The LC50 values of compounds A7, A18, and A20–A22 against pine wood nematode (Bursaphelenchus xylophilus), rice stem nematode (Aphelenchoides besseyi), and sweet potato stem nematode (Ditylenchus destructor) were 1.39–3.09 mg/L, which were significantly better than the control nematicide tioxazafen (106, 49.0, and 75.0 mg/L, respectively). Compound A7 had an outstanding inhibitory effect on nematode feeding, reproductive ability, and egg hatching. Compound A7 effectively promoted the oxidative stress of nematodes and caused intestinal damage to nematodes. Compound A7 significantly inhibited the activity of succinate dehydrogenase (SDH) in nematodes, leading to blockage of electron transfer in the respiratory chain and thereby hindering the synthesis of adenosine triphosphate (ATP), which consequently affects the entire oxidative phosphorylation process to finally cause nematode death. Therefore, compound A7 can be used as a potential SDH inhibitor in nematicide applications

Discovery and Mechanism of a Nematicide Candidate (<b>W3</b>): A Novel Amide Compound Containing a Cyclopropyl Moiety

To find novel nematicides, we screened the nematicidal activity of compounds in our laboratory compound library. Interestingly, the compound N-((1R,2R)-2-(2-fluoro-4-(trifluoromethyl)­phenyl)­cyclopropyl)-2-(trifluoromethyl)­benzamide (W3) showed a broad spectrum and excellent nematicidal activity. The LC50 values of compound W3 against second-stage juveniles of Bursaphelenchus xylophilus (B. xylophilus), Aphelenchoides besseyi, and Ditylenchus destructor are 1.30, 1.63, and 0.72 mg/L, respectively. Nematicidal activities of compound W3 against second-stage juveniles of Meloidogyne incognita were 87.66% at 100 mg/L. Meanwhile, compound W3 can not only observably inhibit the feeding, reproduction, and egg hatching of B. xylophilus but can also effectively promote the oxidative stress adverse reactions of nematodes and cause intestinal damage. Compound W3 can promote the production of MDA and inhibit the activities of defense enzymes SOD and GST in B. xylophilus. Compound W3 can affect the transcription of genes involved in regulating the tricarboxylic acid cycle in nematodes, resulting in weakened nematode respiration and reduced nematode activity and even death. In addition, compound W3 had good inhibitory activity against five pathogenic fungi. Among them, the EC50 of compound W3 against Fusarium graminearum was 8.4 mg/L. In the future, we will devote ourselves to the toxicological and structural optimization research of the candidate nematicide W3

Discovery of Novel Chromone Derivatives Containing a Sulfonamide Moiety as Anti-ToCV Agents through the Tomato Chlorosis Virus Coat Protein-Oriented Screening Method

A number of novel chromone derivatives containing sulfonamide moieties were designed and synthesized, and the activity of compounds against tomato chlorosis virus (ToCV) was assessed using the ToCVCP-oriented screening method. Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) models were established based on the dissociation constant (Kd) values of the target compounds, and compound 35 was designed and synthesized with the aid of CoMFA and CoMSIA models. The study of affinity interaction indicated that compound 35 exhibited excellent affinity with ToCVCP with a Kd value of 0.11 μM, which was better than that of the positive control agents xiangcaoliusuobingmi (0.44 μM) and ningnanmycin (0.79 μM). In addition, the in vivo inhibitory effect of compound 35 on the ToCVCP gene was evaluated by the quantitative real-time polymerase chain reaction. ToCVCP gene expression levels of the compound 35 treatment group were reduced by 67.2%, which was better than that of the positive control agent ningnanmycin (59.5%). Therefore, compound 35 can be used as a potential anti-ToCV drug in the future

Novel Cinnamic Acid Derivatives Containing the 1,3,4-Oxadiazole Moiety: Design, Synthesis, Antibacterial Activities, and Mechanisms

There is a lack of effective antibacterial agents against rice bacterial leaf streak and leaf blight. Cinnamic acid derivatives containing the 1,3,4-oxadiazole moiety were synthesized, and their antibacterial activities against Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo) were evaluated. Based on the three-dimensional quantitative structure–activity relationship (3D-QSAR) model, compound 31 with better antibacterial activity against Xoc was designed and synthesized, and the 50% effective concentration (EC50) value was 0.2 mg/L. The curative and protective activities of compound 31 against rice bacterial leaf streak at 100 mg/L were 39.5 and 35.4%, respectively, which were higher than those of thiodiazole copper (28.4 and 20.7%, respectively). The antibacterial activity of compound 31 against rice bacterial leaf streak is closely associated with the activity of related defensive enzymes and the increase in glutathione metabolism

Novel Cinnamic Acid Derivatives Containing the 1,3,4-Oxadiazole Moiety: Design, Synthesis, Antibacterial Activities, and Mechanisms

There is a lack of effective antibacterial agents against rice bacterial leaf streak and leaf blight. Cinnamic acid derivatives containing the 1,3,4-oxadiazole moiety were synthesized, and their antibacterial activities against Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo) were evaluated. Based on the three-dimensional quantitative structure–activity relationship (3D-QSAR) model, compound 31 with better antibacterial activity against Xoc was designed and synthesized, and the 50% effective concentration (EC50) value was 0.2 mg/L. The curative and protective activities of compound 31 against rice bacterial leaf streak at 100 mg/L were 39.5 and 35.4%, respectively, which were higher than those of thiodiazole copper (28.4 and 20.7%, respectively). The antibacterial activity of compound 31 against rice bacterial leaf streak is closely associated with the activity of related defensive enzymes and the increase in glutathione metabolism