Alkaloids of the Mexican Bean Beetle, Epilachna varivestis (Coccinellidae)

Attygalle, Athula B.; Xu, Shang-Cheng; McCormick, Kevin D.; Meinwald, Jerrold; Blankespoor, Curtis L.; Eisner, Thomas

doi:10.1016/0040-4020(93)80019-p

Cited by 61 publications

(42 citation statements)

References 16 publications

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“…When attacked, adults emit droplets of blood from knee joints ("reflex bleeding"). The fluid, which is deterrent to ants and spiders (20,21), is devoid of azamacrolides but contains an alternative defensive chemical, the homotropane alkaloid euphococcinine (21), along with a variety of additional alkaloids (22).…”

Section: Discussionmentioning

confidence: 99%

Azamacrolides: a family of alkaloids from the pupal defensive secretion of a ladybird beetle (Epilachna varivestis).

Attygalle

McCormick

Blankespoor

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

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Defensive droplets from glandular hairs of the pupa of the Mexican bean beetle, Epilachna varivestis, contain a group of structurally novel alkaloids, the azamacrolides. The major constituent of this secretion, epilachnene, is shown to be (5Z)-11-propyl-12-azacyclotetradec-5-en-14-olide. The secretion also contains an epilachnadiene and trace amounts of three closely related components. (Fig. 1). Suspecting this fluid to be defensive, we exposed pupae to ant attacks in a series of laboratory presentations. The pupae were individually placed on the bottom of small Petri dishes that served as the foraging arenas for laboratory colonies of the ants (Leptothorax longispinosus). The results, which were videotaped, were consistent and dramatic. The moment an individual ant, in an exploratory approach to the pupa, contacted some of the glandular hairs, it backed away and cleansed itself. While retreating, it repeatedly dragged its mouthparts and/or antennae against the substrate. None of the pupae (n = 10; each in a different arena) were injured during the 10-min presentations, although each was contacted by dozens of ants during this period (all pupae eventually gave rise to adults). We proceeded to collect the secretory droplets for analysis and here report on the chemicals isolated from the fluid (5). MATERIALS AND METHODSSample Collection. Secretion from the glandular hairs, collected with microcapillaries, was sealed directly in glass tubes (1.8 x 20 mm) or extracted with ether or dichloromethane (100 ul). For NMR spectroscopy, a sample (500 pupae) was taken up in 400 ul of C2HC13 (2H, 99.96%).Analytical Procedures. Samples were analyzed by gas chromatography (GC) on a Hewlett-Packard (HP) 5890 instruThe publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. ment equipped with a split/splitless injector, a flame ionization detector, and an HP 3396A integrator. Undiluted samples in glass capillaries were injected by a solid sampling technique (6, 7); solutions were introduced by splitless injection. Low-resolution mass spectrometry (MS) was carried out with an HP 5890 gas chromatograph linked to a Finnigan ion-trap detector (ITD 800) or an HP mass selective detector. Chemical ionization mass spectra were obtained on the ITD with methane as the reagent gas. High-resolution mass spectra were obtained on a Kratos 890 instrument. Gas-phase IR spectra were obtained with an HP 5890 gas chromatograph linked to an HP 5965A IR detector. Unless otherwise noted, 1H and 13C NMR spectra were obtained in C2HC13 on a Varian XL-400 instrument.Derivatization Techniques. (i) Microhydrogenation. A small sample of secretion in ether (50 ,ul) was placed in a glass vial and =0.5 mg of 10%o Pd on activated charcoal was added. A balloon filled with hydrogen was attached to the vial. After 10 hr, 25 ul of ether was added and the supernatant was withdrawn and examined by GC/MS.(ii) A...

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Section: Discussionmentioning

confidence: 99%

Azamacrolides: a family of alkaloids from the pupal defensive secretion of a ladybird beetle (Epilachna varivestis).

Attygalle

McCormick

Blankespoor

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

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“…Furthermore, eggs of Exochomus 4-pustulatus and E. varivestis are known to contain alkaloids (Daloze et al, 1995). Alkaloids present in the eggs and other juvenile stages have been found to be either the same as in the adult haemolymph (Lognay et al, 1996) or to differ from adult alkaloid pattern (Attygale et al, 1993;Proksch et al, 1993).…”

Section: Alkaloidal Deterrents Produced De Novamentioning

confidence: 99%

Chemical Protection of Insect Eggs

Blum¹,

Hilker²

2003

Chemoecology of Insect Eggs and Egg Deposition

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“…The solvent was evaporated. The residue was applied to silica gel column chromatography (5% EtOAc in hexane) to give (2S,6S 2,18.5,19.4,21.9,34.1,36.4,36.6,55.5,58.0,77.1,95.5. Anal.…”

Section: (4s)-4-benzyl-3-[(s)-6-methoxymethoxynonanoyl]-2-oxazolidinomentioning

confidence: 99%

“…Dihydropinidine was isolated from the Mexican bean beetle, Epilachna varivestis, 2) and epidihydropinidine was isolated from Pinus engelmannii.…”

mentioning

confidence: 99%

Syntheses of (+)- and (−)-Dihydropinidine and (+)- and (−)-Epidihydropinidine by Using Yeast Reduction of Methyl (2-oxocyclohexyl)acetate

Yamauchi

Mori

Hirai

et al. 2004

Bioscience, Biotechnology, and Biochemistry

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Alkaloids of the Mexican Bean Beetle, Epilachna varivestis (Coccinellidae)

Cited by 61 publications

References 16 publications

Azamacrolides: a family of alkaloids from the pupal defensive secretion of a ladybird beetle (Epilachna varivestis).

Azamacrolides: a family of alkaloids from the pupal defensive secretion of a ladybird beetle (Epilachna varivestis).

Chemical Protection of Insect Eggs

Syntheses of (+)- and (−)-Dihydropinidine and (+)- and (−)-Epidihydropinidine by Using Yeast Reduction of Methyl (2-oxocyclohexyl)acetate

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