Porphyric insecticides. IV: Structure‐activity study of substituted phenanthrolines

Abstract

The porphyric-insecticide-modulating activities of 1,lO-phenanthroline and eight of its analogs were investigated. The insecticidal efficacy of these compounds was closely associated with their ability to enhance the conversion of exogenous baminolevulinic acid (ALA) to protoporphyrin IX (Proto). As observed for photodynamic herbicidal effects in plants, the presence of nitrogen atoms at positions 1 and 10 of the macrocycle was essential for porphyric insecticidal activity. This was evidenced by the very limited activity of phenanthrene, in which positions 1 and 10 are occupied by carbon instead of nitrogen atoms. On the other hand, enhancement of Proto formation and porphyric insecticidal activity were maintained following methyl, chloro and nitro group substitution at the periphery of 1,lO-phenanthroline. In contrast, Proto levels and photodynamic toxicity were reduced by hydroxy and phenyl substitution at the same positions. Benzyl substitution at the 2-3 and 8-9 positions was also inhibitory. Quantitative structure-activity calculations suggested a relationship between peripheral group substitution and physicochemical properties of the substituted compounds. Electron density changes in 1 ,lo-phenanthroline and its analogs that appeared to be related to reduced efficacy included (a) appearance of positive charge-binding volumes at positions 4 and 7 of the 1,lO-phenanthroline macrocycle, which flanks positive charge-repelling volumes, (b) a dramatic increase in superdelocalisability (i.e. electron density) over some unoccupied molecular orbitals, and (c) electronic charge at positions 1 and 10 of the macrocycle. Large increases in van der Waals volumes also exerted negative effects on insecticidal efficacy.

Understanding the interaction mechanism of carbazole/anthracene with N,N-dimethylformamide: NMR study substantiated carbazole separation

“…Anthracene is used as a raw material for the production of anthraquinone, which is used to prepare bio-degradable materials, 3 colorants, 4 anti-diabetics, 5,6 and photoredox catalysts. 7 Phenanthrene and carbazole are used for synthetic dyes, 8 pesticides, 9 pharmaceuticals 10 and photoelectric materials. 11 Along with the development of fine chemicals and the advancement of organic synthesis, there is an increasing demand for high purity anthracene, phenanthrene, and carbazole.…”

Synthesis and Antitumor Activity of Evodiamine Derivatives With Nitro, Amino, and Methoxy Groups

“…21 The insecticidal activity could be enhanced by nitro group substitution at the periphery of 1,10-phenanthroline. 22 So, the introduction of nitro and amino groups are important chemical modifications that can alter the hydrophobic and electronic properties of a molecule. 23 Generally, structural modification of EVO is achieved at the 3 and 10 positions, while there have been scarce reports concerning 2-position derivatives.…”

Formation of Solid Solution and Ternary Phase Diagrams of Anthracene and Phenanthrene in Different Organic Solvents

“…The molecular structures of these compounds are shown in Figure . ANT and PHE have received great attention from industrial manufacturers and scientific researchers because of their special polycyclic structure; the compounds are widely used in dyes, , pesticides, , pharmaceuticals, fuels, photoelectric materials, , and many other fields. ANT and PHE are known to form solid solutions. − Crude ANT from coal tar contains approximately 35 % to 45 % ANT, 15 % to 25 % PHE, and 10 % to 20 % carbazole.…”