The Pyrrolizidine Alkaloids

Robins, David J.

doi:10.1007/978-3-7091-8656-5_4

Cited by 59 publications

(9 citation statements)

References 144 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Toxicity studies have shown that these three classes of compounds can have profound physiological effects on predators (e.g. Blum, 198 1; Robins, 1982;Ehmke et al, 1991;Hartmann & Witte, 1995). Behavioral studies have demonstrated that the presence of these compounds can deter predation (e.g.…”

Section: Review Of Secondary Compounds and Their Acquisitionmentioning

confidence: 99%

The evolution of chemical defences and mating systems in tiger moths (Lepidoptera: Arctiidae)

Weller

Jacobson

Conner

1999

Biological Journal of the Linnean Society

114

View full text Add to dashboard Cite

The origin and evolution of allelochemical sequestration in tiger moths (Arctiidae) is a complex interplay of larval and adult strategies and phylogenetic history. Using a phylogeny of Arctiidae, we examine the acquisition of secondary compounds from larval host plants and the use of secondary compounds and ultrasound in male courtship displays. We note that two sets of defensive signals (secondary chemicals and ultrasound) have been incorporated independently into arctiid courtship displays. Pyrrolizidine alkaloids are used in larval defence, and transformed into male courtship pheromones in several lineages. Phylogenetic inertia best explains the presence of adult collection and use of PAS in the absence of larval sequestration. Ultrasound, an adult defensive display directed at bats and other predators, has also been incorporated into arctiid mating displays. Sensory exploitation appears to underlie this co-option of defence signals for mating purposes.

show abstract

Section: Review Of Secondary Compounds and Their Acquisitionmentioning

confidence: 99%

The evolution of chemical defences and mating systems in tiger moths (Lepidoptera: Arctiidae)

Weller

Jacobson

Conner

1999

Biological Journal of the Linnean Society

114

View full text Add to dashboard Cite

show abstract

“…-The present analysis continues our structural studies of pyrrolizidine alkaloids whose structure and/or toxicity is of particular interest [ 1-51. Pyrrolizidine alkaloids frequently occur naturally as macrocyclic diesters in which a pyrrolizidine diol (necine) is esterified with a diacid to produce 11-, 12-, 13-or 14-membered rings [6] [7]. Retronecine (1) is the most common necine and its macrocyclic diesters are hepatotoxic [8].…”

mentioning

confidence: 99%

“…The Figure shows how the picrate ion and the alkaloid analogue are linked through the phenolic 0-atom, 0 (7), of the picrate and the N-atom, N (4), of the alkaloid aaalogue. [0 (7) ... N(4), 2.664(5) A; 0 (7).. .H(4), 1.684(5) A, angle O (7) ... H(4)-N (4), 148.3 (4)"l. The dimensions of the picrate ion are normal. The ring angle at C (1) is typically low at 110.1 (5)"and the bondsC(l)-C(2)andC(l)-C(6)arelong, 1.453(9) and 1.442 (10) A, respectively.…”

mentioning

confidence: 99%

“…0 (7)-atom is displaced by 0.14 A from this plane, but forms a good mean-plane with C ( l ) and its two adjoining C-atoms. The two adjacent N02-groups are considerably tilted from the ring mean-plane; 24.3 ' for group N(8), with distance O (7) ... O(9) of 2.727(7) A, and 50.6" for group N(14)…”

mentioning

confidence: 99%

“…The pyrrolizidine nuclei of all eight pyrrolizidine alkaloids exist in the exopuckered form with C (6)-atom and the unsaturated five-membered ring on opposite sides of the plane defined by atoms N (4), C (5) and C (7). The puckering angle between planes defined by atoms C(5), C(6), C(7) and C(5), N(4), C(8) varies from 35" to 46" [here 44.3 (2)"l. The angle between the least-squares planes defined by atoms C(1), C(2), C(3), N(4), C(8) and C(5), N(4), C(8), C(7) is 124.5 (O)", close to the average value for retronecine-derived pyrrolizidine alkaloids.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The Crystal Structure of 1,2‐Didehydrocrotalanine Picrate: A Macrocyclic Pyrrolizidine Alkaloid Analogue

Stœckli-Evans

Robins

1983

Helvetica Chimica Acta

View full text Add to dashboard Cite

Summary1,2-Didehydrocrotalanine (2) is the first synthetic macrocyclic pyrrolizidine alkaloid analogue to be studied by X-ray crystallography. The crystal structure was solved by multisolution direct methods and refined by full-matrix least-squares to R = 0.036 for 693 reflections. The alkaloid analogue has an 1 1-membered macrocycle containing two ester groups with their carbonyl groups nearly antiparallel.Introduction. -The present analysis continues our structural studies of pyrrolizidine alkaloids whose structure and/or toxicity is of particular interest [ 1-51. Pyrrolizidine alkaloids frequently occur naturally as macrocyclic diesters in which a pyrrolizidine diol (necine) is esterified with a diacid to produce 11-, 12-, 13-or 14-membered rings [6] [7]. Retronecine (1) is the most common necine and its macrocyclic diesters are hepatotoxic [8]. About 25 naturally occuring 1 1-membered pyrrolizidine alkaloids have been isolated, but synthesis of these macrocyclic diesters has proved difficult [9]. Recently, Robins and co-workers [ 101 have synthesised one natural and six unnatural 1 1-membered macrocyclic diesters from (+ )-

show abstract

Asteraceae Martinov

and¹,

Tyrl²

2012

Toxic Plants of North America

View full text Add to dashboard Cite

The Pyrrolizidine Alkaloids

Cited by 59 publications

References 144 publications

The evolution of chemical defences and mating systems in tiger moths (Lepidoptera: Arctiidae)

The evolution of chemical defences and mating systems in tiger moths (Lepidoptera: Arctiidae)

The Crystal Structure of 1,2‐Didehydrocrotalanine Picrate: A Macrocyclic Pyrrolizidine Alkaloid Analogue

Asteraceae Martinov

Contact Info

Product

Resources

About