Bollenbacher W E, Goodman W, Vedeckis W V, Gilbert L I
Steroids. 1976 Mar;27(3):309-24. doi: 10.1016/0039-128x(76)90053-2.
The in vitro secretory product of larval Sarcophage bullata ring glands has been identified as 2beta, 3beta, 14alpha, 22R, 25-pentahydroxy-5beta-cholest-7-en-6-one (alpha-ecdysone). Mid to late 3rd instar larval ecdysones were isolated and identified as 2beta, 3beta, 14alpha, 20R, 22R, 25-hexahydroxy-5beta-cholest-7-en-6-one (beta-ecdysone) and alpha-ecdysone at a ratio of 27:1. The low level of alpha-ecdysone in vivo, relative to its exclusive in vitro synthesis and secretion by the ring glands, is a function of the very active C20 hydroxylation mechanism in tissues peripheral to the ring gland. The role of alpha-ecdysone as a prohormone in dipteran metamorphosis is discussed.
已鉴定出大肉蝇幼虫环腺的体外分泌产物为2β, 3β, 14α, 22R, 25-五羟基-5β-胆甾-7-烯-6-酮（α-蜕皮激素）。分离出三龄幼虫中后期的蜕皮激素，并鉴定为2β, 3β, 14α, 20R, 22R, 25-六羟基-5β-胆甾-7-烯-6-酮（β-蜕皮激素）和α-蜕皮激素，二者比例为27:1。相对于其仅在体外由环腺合成和分泌而言，体内α-蜕皮激素水平较低，这是环腺外周组织中非常活跃的C20羟基化机制作用的结果。文中讨论了α-蜕皮激素作为双翅目变态前体激素的作用。
