Application of Capillary and Free-Flow Zone Electrophoresis for Analysis and Purification of Antimicrobial β-Alanyl-tyrosine from Hemolymph of Fleshfly Neobellieria bullata

The problem of a growing resistance of bacteria and other microorganisms to conventional antibiotics gave rise to a search for new potent antimicrobial agents. Insect antimicrobial peptides (AMPs) seem to be promising novel potential anti-infective therapeutics. The dipeptide β-alanyl-tyrosine (β-Ala-Tyr) is one of the endogenous insect toxins exhibiting antibacterial activity against both Gram-negative and Gram-positive bacteria. Prior to testing its other antimicrobial activities, it has to be prepared in a pure form. In this study, we have developed a capillary zone electrophoresis (CZE) method for analysis of β‑Ala‑Tyr isolated from the extract of the hemolymph of larvae of the fleshfly Neobellieria bullata by reversed-phase high-performance liquid chromatography (RP-HPLC). Based on our previously described correlation between CZE and free-flow zone electrophoresis (FFZE), analytical CZE separation of β‑Ala‑Tyr and its admixtures have been converted into preparative purification of β‑Ala‑Tyr by FFZE with preparative capacity of 45.5 mg per hour. The high purity degree of the β‑Ala‑Tyr obtained by FFZE fractionation was confirmed by its subsequent CZE analysis.

Evaluating the quality of the Mexican fruit-fly, Anastrepha ludens, as host for the parasitoid Melittobia digitata

We investigated the presence of Melittobia digitata (Hymenoptera: Eulophidae) and its associations with its natural hosts in Veracruz, Mexico. The parasitoid was confirmed to be present and found to attack prepupae of Trypoxylon and Sceliphron (Hymenoptera: Crabronidae and Sphecidae, respectively) mud daubers as well as pupae of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae). Since A. ludens is a very important pest of citrus and mango in Mexico and Central America, we evaluated, in laboratory experiments, the quality of A. ludens as host of M. digitata comparing the development of the parasitoid in another unrelated fly species (Sarcophaga [Neobellieria] bullata) (Diptera: Sarcophagidae) and in mud dauber wasps (Trypoxylon sp. and Sceliphron sp.). The Mexican fruit fly appears to be a good-quality host for M. digitata, and the results are discussed in the context of their possible interest as a natural enemy of A. ludens.