Plant analysis by butterflies: occurrence of cyclopentenylglycines in Passifloraceae, Flacourtiaceae, and Turneraceae and discovery of the novel nonproteinogenic amino acid 2-(3'-cyclopentenyl)glycine in Rinorea.
Following records about feeding habits of nymphalid butterflies, a novel nonproteinogenic L-amino acid, (S)-2-(3'-cyclopentenyl)glycine (11), was discovered in Rinorea ilicifolia, a species where the presence of a cyclopentanoid natural product of this kind was neither known nor anticipated from the taxonomic point of view. Another novel amino acid, (2S,1'S,2'S)-2-(2'-hydroxy-3'-cyclopentenyl)glycine (12), the stereochemistry of which was determined by single-crystal X-ray diffraction, was shown to occur in species belonging to Flacourtiaceae, Passifloraceae, and Turneraceae. These species, many of which serve as hosts for nymphalid butterflies (Acraeinae, Heliconiinae, Argynninae), also produce 2-(2'-cyclopentenyl)glycine. Cyclopentenylglycines are proposed to be novel chemical recognition templates for plant-insect interactions. Ratios between the epimers of (2S)-2-(2'-cyclopentenyl)glycine, which co-occur in plants, were determined by (1)H NMR spectroscopy. Contrary to a previous report, the (2S,1'R) epimer always appears to predominate over the (2S,1'S) epimer. Stereochemical aspects of biosynthesis of natural cyclopentanoid cyanogenic glycosides are discussed in relation to these findings.
Clausen
Vicki
V
Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Frydenvang
Karla
K
Koopmann
Ricarda
R
Jørgensen
Lise Bolt
LB
Abbiw
Daniel K
DK
Ekpe
Patrick
P
Jaroszewski
Jerzy W
JW
D000818:Animals; D002080:Butterflies / Q000378:metabolism*; D018360:Crystallography, X-Ray; D005247:Feeding Behavior / Q000502:physiology; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D029598:Passiflora / Q000737:chemistry; D010944:Plants / Q000737:chemistry*
C457144:2-(2'-hydroxy-3'-cyclopentenyl)glycine; C026228:cyclopentenylglycine; D005998:Glycine