Evaluation of the inhibitory effect of a series of secondary plant compounds including steroidal alkaloids and glycoalkaloids on larvae of the red flour beetle, Tribolium castaneum, was investigated. Larval growth was inhibited on artificial diets containing 1 mumol g-1 diet of the glycoalkaloids solamargine, solasonine and tomatine, whereas the corresponding aglycones solasodine and tomatidine, and also tomatidenol, were inactive. The inhibitory effect of solamargine and tomatine, but not of solasonine, was completely abolished by addition of 1 mumol g-1 diet cholesterol and/or sitosterol. Nonetheless, synthetic cholesteryl tomatide displayed significant activity at 2 mumol g-1 diet. Parallel studies with the tobacco hornworm, Manduca sexta, showed marked inhibitory activity of tomatine at a dietary concentration of 1 mumol g-1, whereas the other compounds did not affect sterol metabolism or larval development. An appraisal of the factors influencing the mode of action of the active steroidal glycoalkaloids is attempted.
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http://dx.doi.org/10.1016/s0031-9422(97)00565-7 | DOI Listing |
Nanoscale Adv
January 2025
Faculty of Chemical and Food Technology, Ho Chi Minh City University of Technology and Education 01 Vo Van Ngan Street, Linh Chieu Ward, Thu Duc City Ho Chi Minh City 700000 Vietnam
Photocatalytic methane oxidation under mild conditions using single-atom catalysts remains an advanced technology. In this work, gold single atoms (Au SAs) were introduced onto TiO nanostructures using a simple method. The resulting performance demonstrated effective conversion of methane into H and C products at room temperature.
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January 2025
Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China.
Artificial photosynthesis of urea from NH and CO seems to remain still essentially unexplored. Herein, three isomorphic three-dimensional covalent organic frameworks with twofold interpenetrated ffc topology are functionalized by benzene, pyrazine, and tetrazine active moieties, respectively. A series of experiment results disclose the gradually enhanced conductivity, light-harvesting capacity, photogenerated carrier separation efficiency, and co-adsorption capacity towards NH and CO in the order of benzene-, pyrazine-, and tetrazine-containing framework.
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January 2025
The Hong Kong Polytechnic University, Department of Applied Biology and Chemical Technology, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Hom, Hong Kong (P.R. China), 000000, Hong Kong, HONG KONG.
A series of new (donor)₂-donor-π-acceptor (D2-D-π-A) and (acceptor)₂-donor-π-acceptor (A2-D-π-A) organic photosensitizers based on the framework of (Z)-2-cyano-3-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)acrylic acid have been synthesized and characterized. By incorporating groups with different electron-donating or withdrawing abilities, such as dibenzothiophene (DBT), dibenzofuran (DBF), and triazine (TA), into the triphenylamine segment, their photophysical properties have been regulated. Theoretical calculations were used to explore how various donor-acceptor combinations influence their hydrogen production performance.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
College of Chemistry, Baicheng Normal University, Baicheng 137018, P. R. China.
Herein, the construction of potential donor-acceptor (D-A) structures was guided using density-functional theory (DFT) calculations. The photocatalytic nitrogen fixation performance of TAPT-CHF was then experimentally determined to be 327.58 μmol g h, which was attributed to its efficient photo-induced charge separation and migration ability.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences, Hangzhou, 310024, P. R. China.
Metal-free photocatalysts derived from earth-abundant elements have drawn significant attention owing to their ample supply for potential large-scale applications. However, it is still challenging to achieve highly efficient photocatalytic performance owing to their sluggish charge separation and lack of active catalytic sites. Herein, we designed and constructed a series of covalently bonded organic semiconductors to enhance water splitting and phenol degradation.
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