ABSTRACT
BACKGROUND: γ-Amino butyric acid (GABA) antagonists are proven targets for control of lepidopteran and other pests. New heterocyclic compounds with high insecticidal activity were discovered using a competitive-intelligence-inspired scaffold-hopping approach to generate analogs of fipronil, a known GABA antagonist. These novel aryl heterocyclic amines (AHAs) displayed broad-spectrum activity on a number of chewing insect pests. RESULTS: Through >370 modifications of the core AHA structure, a 7-pyrazolopyridine lead molecule was found to exhibit much improved activity on a number of insect pests. In field trial studies, its performance was 2-4 times lower than commercial standards and also appeared to be species dependent, with good activity seen for larvae of Spodoptera exigua, but inactivity on larvae of Trichoplusia ni. CONCLUSION: An extensive investigational biology effort demonstrated that these AHA analogs appear to have multiple modes of action, including GABA receptor antagonism and mitopotential or uncoupler activity. The limited capability in larvae of T. ni to convert the lead molecule to its associated open form correlates with the low toxicity of the lead molecule in this species. This work has provided information that could aid investigations of novel GABA antagonists. © 2016 Society of Chemical Industry.
Subject(s)
Amines/pharmacology , Insecticides/pharmacology , Moths/drug effects , Amines/chemical synthesis , Amines/pharmacokinetics , Animals , Biological Availability , Drug Discovery , Insecticides/chemical synthesis , Insecticides/pharmacokinetics , Larva/drug effects , Moths/growth & development , Spodoptera/drug effects , Spodoptera/growth & developmentABSTRACT
The ansacarbamitocins are a new family of maytansinoids that are unusually substituted with a glucose subunit and two carbamate functional groups and exhibit modest activity against some agricultural fungal disease organisms. Ansacarbamitocins A-F ( 1- 6) all consist of the same macrocyclic core as the ansamitocins, with variation occurring on the glucose unit, while ansacarbamitocins A1 and B1 ( 7, 8) additionally lack the epoxide group on C-4 and C-5.
Subject(s)
Actinomycetales/chemistry , Anti-Bacterial Agents/isolation & purification , Maytansine/analogs & derivatives , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/classification , Anti-Bacterial Agents/pharmacology , Ascomycota/drug effects , Maytansine/chemistry , Maytansine/classification , Maytansine/isolation & purification , Maytansine/pharmacology , Molecular Structure , Structure-Activity RelationshipABSTRACT
9-Borabicyclononane (9-BBN) has been utilized to protect functionalized amino acids for potential chemoselective side chain manipulation. The 9-BBN group imparts organic solubility to otherwise hydrophilic molecules and is tolerant of a wide range of reaction conditions. The high degree of solubility of these molecules in THF is particularly noteworthy. It is cleaved with either aqueous HCl or by exchange with ethylenediamine in methanol. [reaction: see text]
