Predominant accumulation of a 3-hydroxy-γ-decalactone in the male rectal gland complex of the Japanese orange fly,Bactrocera tsuneonis

Abstract

The Japanese orange fly, Bactrocera tsuneonis, infests various citrus crops. While male pheromone components accumulated in the rectal glands are well-characterized for Bactrocera, but information regarding the chemical factors involved in the life cycles of B. tsuneonis remains scarce. Herein, several volatile chemicals including a γ-decalactone, (3R,4R)-3-hydroxy-4-decanolide [(3R,4R)-HD], were identified as major components, along with acetamide and spiroketals as minor components in the rectal gland complexes of male B. tsuneonis flies. The lactone (3R,4R)-HD was also identified in female rectal gland complexes. The amount of this compound in mature males was significantly higher than those observed in females and immature males. The lactone (3R,4R)-HD was detected in flies fed with sucrose only, indicating that this lactone is not derived from dietary sources during adulthood, but biosynthesized in vivo. The predominant accumulation of (3R,4R)-HD in mature males also suggests a possible role in reproductive behavior.

Concise Stereoselective Synthesis of β-Hydroxy-γ-lactones: (4R,5R)-4-Hydroxy-γ-decalactone from the Japanese Orange Fly and Enantiomers of Arachnid Harvestmen Isolates

“…The specific rotation of 2, [α] D 25 +46 (c 0.9, MeOH), and the spectroscopic data was in good agreement with that reported for the natural isolate, [α] D 23 +61.5 (c 0.065, MeOH). 4 Similarly, the spectroscopic data for ent-3 was in excellent agreement to that of the natural isolate and the synthesized compound in the literature. 6 The specific rotation value of ent-3, [α] D 25 −33 (c 0.5, CHCl 3 ), matches well with that of the synthesized compound, [α] D −32.3 (c 0.13, CHCl 3 ), in the literature.…”

“…2 New molecules are continuously isolated from these species for pest control and bioactivity studies placing a continuing demand for efficient strategies for their synthesis. 3 Ono and co-workers 4 recently isolated (4R,5R)-4-hydroxy-γdecalactone (2) as the major component in the male rectal glands of the Japanese orange fly, Bactrocera tsuneonis, which infests various citrus crops. This lactone is also present in the female and immature males but in significantly less quantity.…”

“…10 The lactone 2 has been synthesized in either enantiomer form by the SAD reaction (Figure 2A), while the corresponding anti-diastereomers were prepared in racemic form by epoxidation of (E)-methyl-3-decenoate (4) and lactonization (Figure 2B). 4 The anti-lactone 3 has been synthesized from commercially available (R)-benzyl glycidyl ether (5) in six steps, requiring two protecting groups and addition of the expensive Evans-auxiliary (Figure 2C). 6 The use of opposite enantiomer resulted in the synthesis of ent-3.…”

“…Ono and co-workers recently isolated (4 R ,5 R )-4-hydroxy-γ-decalactone ( 2 ) as the major component in the male rectal glands of the Japanese orange fly, Bactrocera tsuneonis , which infests various citrus crops. This lactone is also present in the female and immature males but in significantly less quantity.…”

A Novel Class of Defensive Compounds in Harvestmen: Hydroxy-γ-Lactones from the Phalangiid Egaenus convexus

“…Regarding the chemistry of Eupnoi, the compounds are similar neither to the acyclic compounds found in sclerosomatid Eupnoi (“sclerosomatid compounds” [sensu]) nor to the aromatic/quinonic compounds from Phalangiinae. , Second, the particular β-hydroxy-γ-lactones as seen in Egaenus have not been found in any other arthropod yet. While lactones with OH groups on the side chains appear to be present in at least some insect species, only one example for an exocrine lactone carrying a hydroxy group in the β-position (a 3-hydroxy-γ-decalactone = 5-hexyl-4-hydroxy-dihydro-furan-2-one from a tephritid fly) has recently been reported …”