(E)-2-(4′-Methyl-3′-pentenylidene)-4-butanolide, Namedβ-Acariolide: A New Monoterpene Lactone from the Mold Mite,Tyrophagus putrescentiae(Acarina: Acaridae)

Abstract

Reinwestigation of the opisthonotal gland secretion of the mold mite, Tyrophagus putrescentiae, resulted in the isolation of a new monoterpene lactone, whose chemical structure was elucidated as (E)-2-(4'-methyl-3'-pentenylidene)-4-butanolide (3), to which we gave the trivial name β-acariolide in relation to β-acaridial {1, (E)-2-(4-methyl-3-pentenylidene)-butanedial}. The compound was synthesized by LiAlH3 (OEt) reduction of 1 and subsequent oxidation involving simultaneous cyclization by using Ag2CO3 on Celite. Both the E- and Z-isomers of β-acariolide (3 and 4) were also prepared by the reaction of α-ethoxaly-γ-butyrolactone (6) and 4-methyl-3-pentenal under basic conditions. Their NMR spectra were compared with each other, and the geometry of the pentenylidene double bond of the isolated compound was concluded as being E.

Chemical Taxonomy Applications of Some Water Mite Species (Acari, Hydrachnidia) Using Fourier Transform Infrared Spectroscopy (FTIR) Methods

“…It is known that this species has a different morphological structure in the family of Eylaidae than all other species of Eylais. Because this species of chitinization is different from the others [21,24,25]. Though there is more chitinization in the species of Torrenticola brevirostris, the same difference is not seen in the graph.…”

“…On the other hand, it is understood that Georgella helvatica, Hygrobates nigromacutlatus, Hydryphantes thoni, and Torrenticola bevirostris are more similar to each other in these functional groups in the same region. This situation does not support the taxonomic order based on structural features at the genus and family level [21][22].…”

3-(4-Methyl-3-pentenyl)-2(5H)-furanone, α,α-Acariolide and 4-(4-Methyl-3-pentenyl)-2(5H)-furanone, α,β-Acariolide:

“…21) The present identiˆcation of 1 and 2 provide the second and third examples of lactones being found among astigmatid mites.…”

The use of the lactone motif in chemical communication

“…158 The related lactone b-acariolide (143) is an oil gland secretion product of the mold mite, Tyrophagus putrescentiae. 159 A semiochemical function of these mite lactones has not been reported yet.…”

“…180,181 The terpenoid (4E,8E)-4,8-dimethyldeca-4,8-dien-10-olide (ferrulactone I, cucujolide I, 155) is used together with 85 as a pheromone by male rusty grain beetles, C. ferrugineus (see above). 106 Feeding experiments with 2 H-and 18 O-labeled farnesol (159) showed retention of the label, determined by GC/MS. 111 Transformation by the beetle is obviously accomplished through oxidative cleavage of the terminal double bond, followed by cyclization as shown in Fig.…”