Carboxylic acids from hairpencils of male Amauris butterflies (Lep.: Danainae).

63 Carboxylic acids were identified from the male hairpencils of four species of the genus Amauris (Lep.: Danainae), namely A. echeria (Stoll), A. hecate (Butler), A. ochlea (Boisduval) and A. albimaculata Butler. Straight chain saturated as well as unsaturated carboxylic acids, some of which containing an additional oxygen function, contribute to the species-specificity of the odour bouquets. Oxygenated fatty acids form a new class of insect volatiles, 5 of the 10 ketoacids found represent new natural products. (E)-7-Oxo-11-tetradecenoic acid is the main volatile component of the hairpencils of A. echeria, the species with the highest amount of oxygenated fatty acids (70% of the extractable volatiles). 9-Hydroxyoctadecanoic acid is a major compound in both A. ochlea and A. albimaculata while in A. hecate oxygenated carboxylic acids are present in minute amounts only.

Crystallization, crystal structure analysis and preliminary molecular model of the bilin binding protein from the insect Pieris brassicae.

The bilin binding protein of the butterfly Pieris brassicae has been prepared, crystallized and its crystal structure determined at high resolution using film and FAST area detector intensity data. The crystallographic asymmetric unit contains a tetramer of identical subunits with a molecular weight of about 90,000. The crystal structure was determined by isomorphous replacement. Use was made of the molecular symmetry to improve phases. A molecular interpretation of the electron density distribution and partial tracing of the polypeptide chain was possible without amino acid sequence information, as the fold is very similar to retinol binding protein. It is characterized by a beta-barrel formed by two orthogonal beta-sheets and an alpha-helix. The bilin pigment seems to be bound within the beta-barrel analogously to retinol in retinol binding protein. The tetramer in the crystal has C2 symmetry and is a dimer of dimers of quasi-equivalent subunits.

Purification of an N-acetyl-D-glucosamine specific lectin (P.B.A.) from epidermal cell membranes of Pieris brassicae L.

We report the isolation and the purification of an N-acetyl-D-glucosamine specific lectin capable of agglutinating either fixed trypsinized rabbit erythrocytes or chitin particles. An agglutinin assay based on the affinity of this lectin for the chitin was devised with fluorescent particles of scorpion cuticle to measure lectin activity during purification steps. Lectin was isolated from epidermal cell membranes; its molecular weight was determined by gel filtration and polyacrylamide electrophoresis in sodium dodecyl sulfate. Mr was estimated to be 43,000. Lectin could be constituted by two subunits. Mr of which was estimated to be 23,000. The specificity of this lectin against N-acetyl-D-glucosamine and its oligomers suggests a possible role in the dynamics of these saccharides during the cuticle cycle.

[Presence in the sub-esophageal ganglinnof the caterpillar (Thaumetopoea pityocampa Schiff) of cells containing anti-alpha-endorphins as revealed by immunofluorescence]. / Préscence dans le ganglion sous-aesophagien de la Chenille processionnaire du Pin (Thaumetopoea pityocampa Schiff) de cellules révélées en immunofluorescence par un anticorps anti-alpha-endorphine.

Immunohistological investigations have been performed with Vertebrate neuropeptide antiserums in the subaesophageal ganglion of larval Thaumetopoea pityocampa (Lepidoptera). Positive immunoreaction was observed in two groups of cells only with an alpha-endorphin-antiserum. These cells are azocarmine ground positive earth and paraldehyde-fuchsin ground negative earth or Gomori ground negative earth. In the brain, immunohistological staining was completely negative.

Antineoplastic agents. 42. The butterfly, Prioneris thestylis.

Isoguanine (2) was found to be an antineoplastic constituent of Prioneris thestylis Dbldy. wings. Three other purine components of the butterfly wings were identified as hypoxanthine (3), uric acid (4) and xanthine (5). Isolation of urocanic acid (6) from the same wing material represented the first detection of this interesting histidine derivative in an arthropod.