Natural and synthetic materials with insect hormone activity. 9. Structure- juvenile activity relationships in simple peptides.

Natural and synthetic materials with insect hormone activity. IV. Specific female sterility effects produced by a juvenile hormone analogue.

Natural and Synthetic Materials with Insect Hormone Activity. 5. Specific Juvenile Hormone Effects in Aliphatic Sesquiterpenes.

The juvenile hormone activity of ethyl or methyl esters of aliphatic sesquiterpenic acids with 0 to 4 double bonds was tested on 8 species of insects belonging to 5 families of Hemiptera and Coleoptera. Special attention was paid to the addition of hydrogen chloride or epoxide groups on or across the double bonds. Certain chemical changes in the molecule appear to cause a general increase of th...

Growth Promotion in Pea Stem Sections. III. By Alkyl Nitriles, Alkyl Acetylenes and Insect Juvenile Hormones.

C(14), C(15), and C(16) alkyl nitriles, and C(16) and C(18) alkyl acetylenes at 10 to 105 micromolar concentrations promote the growth of stem sections from red-light-exposed seedlings of dwarf peas (Pisum sativum L. cv. Progress No. 9). Similar results were obtained with substances active as insect juvenile hormones, namely farnesol, the racemic ethyl ester of 1 of the natural hormones, and a ...

Identification of multiple peptides homologous to cockroach and cricket allatostatins in the stick insect Carausius morosus.

Eighteen peptides were isolated from brain extracts of the stick insect Carausius morosus. The peptides were purified in four steps by high-performance liquid chromatography, monitored by their ability to inhibit juvenile hormone biosynthesis by corpora allata of the cricket Gryllus bimaculatus in vitro, and chemically characterised by Edman degradation and mass spectrometry. We obtained comple...

Structure-activity relationships among random nylon-3 copolymers that mimic antibacterial host-defense peptides.

Host-defense peptides are natural antibiotics produced by multicellular organisms to ward off bacterial infection. Since the discovery of these molecules in the 1980s, a great deal of effort has been devoted to elucidating their mechanisms of action and to developing analogues with improved properties for possible therapeutic use. The vast majority of this effort has focused on materials compos...