Isolation of crustecdysone (20R-hydroxyecdysone) from a crayfish (Jasus lalandei H. Milne-Edwards)

Abstract

1. A small amount (2mg.) of crustecdysone, a moulting hormone of crustaceans, was isolated from 1 ton of crayfish waste. 2. The purification procedure used was developed with the aid of crustacean and insect bioassays. 3. CM-Sephadex was found to be superior to Sephadex and very effective for the chromatographic separation of crustecdysone from other non-ionic compounds. The higher efficiency of CM-Sephadex is attributed to the greater number of carboxyl groups available for hydrogen-bonding. 4. Reversed-phase chromatography, with butan-1-ol-cyclohexane mixtures as the stationary phase and water as the flowing phase, proved superior to countercurrent distribution with these solvents for the fractionation of purified extracts. 5. A second moulting hormone, deoxycrustecdysone, and the red-concentrating hormone were obtained in a partially purified form.

The regulation of expression of insect cuticle protein genes

“…Precursors (generally ecdysone or 3-dehydroecdysone) are secreted by prothoracic glands and converted into a more potent hormone, 20-hydroxy-ecdysone (20E) (Hoffmeister et al, 1967;Horn et al, 1968) by peripheral tissues (King et al, 1974). These findings have opened the way for systematic measurements of ecdysteroid titers throughout development in various arthropods.…”

On the reported occurrence of an ecdysone-like steroid in the freshwater snail, Biomphalaria glabrata (Pulmonata; Basommatophora), intermediate host of Schistosoma mansoni

“…Muftic claims to have obtained 8 mg of pure substance from 1000 1-month-old Biomphalaria glabrata, which would amount to about 200-300 g wet weight of whole snail (shell plus all tissues). This ratio (8 mg from 250 + 50 g) compares with 9-9 mg of ecdysone from 11-43 kg of Tobacco Hornworm pupae (10 % of the crude extract from 12-7 kg was set aside) (Kaplanis et al 1966 a); 2 mg from 1 ton of crayfish waste (Horn et al 1968); and less than enough crustecdysone to permit characterization after extraction of 3 tons of Grangon shrimps (Hampshire & Horn, 1966).…”

Do arthropods feel anxious during molts?

“…In crustaceans, as in most other arthropods, 20E (formerly also known as crustecdysone) is the main ecdysteroid (Horn et al, 1968). Injections of high amounts of exogenous 20E into arthropods are generally able to induce pre-molt but not the entire molting cascade comprising ecdysis and post-molt events, whereas lower Crayfish (n=6) were tested individually every 2-3 days in a dark/light plus-maze (DLPM).…”