Biodegradable electrospun fibers as sustained-release carriers of insect pheromones for field trapping of Spodoptera litura (Lepidoptera: Noctuidae).

BACKGROUND: Insect pheromones are highly effective and environmentally friendly, and are widely used in the monitoring and trapping of pests. However, many researchers have found that various factors such as ultraviolet light and temperature in the field environment can accelerate the volatilization of pheromones, thus affecting the actual control effect. In recent years, electrospinning technology has demonstrated remarkable potential in the preparation of sustained carriers. Moreover, the utilization of biodegradable materials in electrospinning presents a promising avenue for the advancement of eco-friendly carriers. RESULTS: In this study, homogeneous and defect-free pheromone carriers were obtained by electrospinning using fully biodegradable polyhydroxybutyrate materials and pheromones of Spodoptera litura. The electrospun fibers with porous structure could continuously release pheromone (the longest can be ≤80 days). They also had low light transmission, hydrophobic protection. More importantly, the pheromone-loaded electrospun fiber carriers showed stable release and good trapping effect in the field. They could trap pests for at least 7 weeks in the field environment without other light stabilizers added. CONCLUSION: Sustained-release carriers constructed by electrospinning and green materials could improve the efficacy of pheromones and ensure environmental friendliness, and provided a tool for the management of S. litura and other pests and sustainable development of agricultural. © 2023 Society of Chemical Industry.

Synthesis and bioactivity studies of sex pheromone analogs of the diamond back moth, Plutella xylostella.

BACKGROUND: Diamondback moth, Plutella xylostella L., is a very important pest of cruciferous vegetables causing excessive economic losses worldwide. Bioactivities of halo-, diazo-, and cyclopropane acetates of P. xylostella sex pheromone have been evaluated using electrophysiology and enzyme inhibition assays. RESULTS: A total of 23 sex pheromone analogs of P. xylostella were designed and synthesized and the result shows that (11Z)-hexadec-11-en-1-yl 2,2,2-trifluoroacetate, (11Z)-hexadec-11-en-1-yl 2,2,3,3,3-pentafluoropropanoate, and (11Z)-hexadec-11-en-1-yl trifluoromethanesulfonate elicited potential inhibitory effects at all doses tested in the electrophysiology and enzyme inhibition assays. Interference of locating the sex pheromone source was found strongest when these three analogs were mixed with the sex pheromone at a 10:1 ratio. In addition, field test showed that the rate of mating disruption was over 90% when (11Z)-hexadec-11-en-1-yl 2,2,2-trifluoroacetate or (11Z)-hexadec-11-en-1-yl 2,2,3,3,3-pentafluoropropanoate was mixed with the sex pheromone at a 10:1 ratio. CONCLUSION: Two sex pheromone antagonists were screen out by electrophysiology, enzyme inhibition assays, wind tunnel and field tests. We believe that these antagonists could be used to establish a novel eco-friendly measure to control P. xylostella and provide evidence for clarifying the specific functions and molecular mechanisms of sex pheromone antagonists. © 2018 Society of Chemical Industry.

Attraction of Coffee Bean Weevil, Araecerus fasciculatus, to Volatiles from the Industrial Yeast Kluyveromyces lactis.

The coffee bean weevil (CBW), Araecerus fasciculatus (De Geer, 1775) (Coleoptera: Anthribidae) is an important pest of stored products such as grains, coffee beans, cassava, and traditional Chinese medicine materials. In China, CBW causes large losses of Daqu, a traditional Chinese liquor fermentation starter, and, unfortunately, the use of conventional insecticides against CBW is not suitable in Daqu storage. We found CBW to be highly attracted to fermenting yeast cultures, such as Kluyveromyces lactis. Eight volatile compounds, produced by fermenting cultures and not by sterile samples, were identified by gas chromatography coupled with mass spectrometry. Five of these substances elicited significant responses in Y-tube behavioral bioassays. Field trapping experiments revealed 2-phenylethanol and 2-phenylethyl acetate to be crucial for attraction of CBW. Results show that yeast volatiles play an important role in host location, and that 2-phenylethanol and 2-phenylethyl acetate could be utilized as potential attractants in monitoring and control systems against this important pest.

Teaching research on student ability training of biomedical engineering specialty / 医疗卫生装备

Objective To design a student training program of biomedical engineering specialty to enhance student ability and employment rate.Methods The program design was executed from the aspects of curricula,teaching content,teaching approach,examination scheme,directed training by tutorial system as well as training integrating university and enterprise.Results The program design gifted the student with high comprehensive quality and professional skills.Conclusion Teaching approaches have to be regulated continuously according to the requirements of employing facilities.

Teaching research on student ability training of biomedical engineering specialty / 医疗卫生装备

Objective To design a student training program of biomedical engineering specialty to enhance student ability and employment rate.Methods The program design was executed from the aspects of curricula,teaching content,teaching approach,examination scheme,directed training by tutorial system as well as training integrating university and enterprise.Results The program design gifted the student with high comprehensive quality and professional skills.Conclusion Teaching approaches have to be regulated continuously according to the requirements of employing facilities.

2-Amino-6-chloro-N-methyl-benzamide.

In the title compound, C8H9ClN2O, the dihedral angle between the benzene ring and the methyl-amide substituent is 68.39 (11)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming layers parallel to the ab plane.

Characterization of three pheromone-binding proteins (PBPs) of Helicoverpa armigera (Hübner) and their binding properties.

Three pheromone-binding proteins of Helicoverpa armigera were cloned and expressed in Escherichia coli. In order to characterize their physiological properties, ligand-binding experiments were performed using five biologically relevant substances including sex pheromones and interspecific signals. The results showed that one of the pheromone-binding proteins, HarmPBP1, binds strongly to each of the two principal pheromone components of H. armigera, (Z)-11-tetradecenal and (Z)-9-hexadecenal, but not to the interspecific signal (Z)-9-tetracecenal. The two remaining pheromone-binding proteins, HarmPBP2 and HarmPBP3, showed only weak affinities with the ligands tested. The 3-D structure of HarmPBP1 was predicted and the docking experiments indicate that the key binding site of (Z)-9-hexadecenal to HarmPBP1 includes Thr112, Lys111, and Phe119 whereas that of (Z)-11-tetradecenal includes Ser9, Trp37, Phe36, and Phe119.

2-Amino-N,3-dimethyl-benzamide.

In the title compound, C9H12N2O, the mean plane through the amide group and the benzene ring form a dihedral angle of 33.93 (7)°. An intra-molecular N-H⋯O hydrogen bond is present. In the crystal, mol-ecules are linked by N-H⋯N and N-H⋯O hydrogen bonds, forming double-stranded chains parallel to the b axis.

Synthesis and insecticidal activity of novel carbamate derivatives as potential dual-binding site acetylcholinesterase inhibitors.

In biological systems, bivalent ligands often possess increased functional affinity for their receptors compared with monovalent ligands. On the basis of the structure of acetylcholinesterase (AChE), a series of novel carbamate heterodimetic derivatives were designed and synthesized with the aim of increasing the potency toward AChE inhibition. The AChE inhibitory ability of all the novel compounds was tested using AChE obtained from the brain of the housefly. The bioassay results showed that compounds 6j, 6k, 6m, 6n, 6p, and 6q had increased inhibitory activities in comparison with parent phenyl N-methylcarbamate (MH) at the concentration of 100 mg/L. Among them, the most potent AChE inhibitor of these compounds was 6q (IC(50) = 12 µM), which showed 62-fold greater AChE inhibitory activity than that of MH and 12-fold greater activity than metolcarb (MT), which suggested that the 3-nitrophenoxy moiety of compound 6q was able to interact with the aromatic amino acid residues lining the gorge and the phenyl N-methylcarbamate moiety was able to interact with the catalytic sites of AChE, simultaneously. The insecticidal activities of compounds 6j, 6k, 6m, 6n, 6p, and 6q were further evaluated. Consistent with the result in vitro bioassay, those compounds demonstrated better activities against Lipaphis erysimi than parent compound MH at the concentration of 300 mg/L, and compound 6q showed the best insecticidal activity, causing 98% mortality after 24 h of treatment.

Synthesis and herbicidal activity of novel N-(2,2,2)-trifluoroethylpyrazole derivatives.

A series of novel N-(2,2,2)-trifluoroethylpyrazole derivatives were synthesized, and their structures were characterized by IR, mass spectroscopy, (1)H NMR, and elementary analysis. The herbicidal activities of target compounds 10a-c and 11a-c were assessed. The bioassay results showed that these pyrazole derivatives exhibited good herbicidal activity. Compound 11a showed the best pre-emergence herbicidal effects against both dicotyledonous and monocotyledonous weeds with good safety to maize and rape at the dosage of 150 g a.i. ha(-1) in greenhouse. Field trials indicated that compound 11a exhibited better herbicidal activity by soil application than the commercial herbicide, metolachlor. Moreover, compound 11a showed the same level of safety to maize as metolachlor.

4-(4-Chloro-5-methyl-3-trifluoro-meth-yl-1H-pyrazol-1-yl)-6-(prop-2-ynyl-oxy)pyrimidine.

The molecule of the title compound, C(12)H(8)ClF(3)N(4)O, is twisted as indicated by the C-O-C-C torsion angle of 76.9 (3)°. Moreover, the trifluoro-methyl group shows rotational disorder of the F atoms, with site-occupancy factors of 0.653 (6) and 0.347 (6). The dihedral angle between the rings is 1.88 (12) Å.

4-Chloro-5-[(5,5-dimethyl-4,5-dihydro-isoxazol-3-yl)sulfonyl-meth-yl]-3-methyl-1-(2,2,2-trifluoro-ethyl)-1H-pyrazole.

The mol-ecule of the title compound, C(12)H(15)ClF(3)N(3)O(3)S, is twisted, as indicated by the C-S-C-C torsion angle of 66.00 (18)° for the atoms linking the ring systems. An intra-molecular C-H⋯F short contact occurs. In the crystal, non-classical C-H⋯O inter-actions, one of which has a short H⋯O contact of 2.28 Å, link the mol-ecules.

4-Bromo-5-[(5,5-dimethyl-4,5-dihydro-isoxazol-3-yl)sulfonyl-meth-yl]-3-methyl-1-(2,2,2-trifluoro-ethyl)-1H-pyrazole.

In the title compound, C(12)H(15)BrF(3)N(3)O(3)S, which has potential herbicidal activity, the mol-ecule is twisted, as indicated by the C-S-C-C torsion angle of 67.86 (19)° for the atoms linking the ring systems. An intra-molecular C-H⋯F short contact occurs and inter-molecular C-H⋯O inter-actions link the mol-ecules in the crystal.

4,6-Bis[5-methyl-3-(trifluoro-meth-yl)pyrazol-1-yl]pyrimidine.

The complete mol-ecule of the the title compound, C(14)H(10)F(6)N(6), is generated by crystallographic twofold symmetry, with two C atoms lying on the roatation axis. The dihedral angle between the central and peripheral rings is 25.97 (8)°.

4-(But-3-yn-yloxy)-6-(4-iodo-1H-pyrazol-1-yl)pyrimidine.

In the title compound, C(11)H(9)IN(4)O, the dihedral angle between the pyrazole and pyrimidine rings is 6.30 (16)°. In the crystal, weak C-H⋯O inter-actions link the mol-ecules.

4-(4-Bromo-3-methyl-1H-pyrazol-1-yl)-6-(but-3-yn-yloxy)pyrimidine.

There are two mol-ecules in the asymmetric unit of the title compound, C(12)H(11)BrN(4)O. The dihedral angles between the pyrazole and pyrimidine rings are 1.28 (17) and 1.56 (17)° in the two mol-ecules. In one of the mol-ecules, the but-3-yn-yloxy side chain is disordered over two sets of sites in a 0.714 (8):0.286 (8) ratio.

(4-Bromo-3,5-dimethyl-1H-pyrazol-1-yl)(2,6-difluoro-phen-yl)methanone.

There are two mol-ecules in the asymmetric unit of the title compound, C(12)H(9)BrF(2)N(2)O. They have very similar conformations: the dihedral angles between their pyrazole and benzene ring systems are 78.4 (3) and 78.6 (4)°. In the crystal, weak aromatic π-π stacking [centroid-centroid separation = 3.696 (5) Å] helps to establish the packing.