The biosynthesis of diterpenoid alkaloids

Benn, M. H.; May, Judith

doi:10.1007/bf02151785

Cited by 16 publications

(2 citation statements)

References 6 publications

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“…Alkaloid synthesis pathways are highly regulated and involve controls at the cell, tissue, plant, and environmental levels (Facchini 2001). Benn and May (1964) indicated that larkspur alkaloids are synthesized in roots, but little is known about further synthesis and translocation.…”

Section: Discussionmentioning

confidence: 99%

Toxic Alkaloid Concentrations in Delphinium Nuttallianum, Delphinium Andersonii, and Delphinium Geyeri in the Intermountain Region

Gardner

Pfister

2007

Rangeland Ecology & Management

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Low larkspurs (Delphinium nuttalliunum Pritz., Delphinium andersonii Gray) and plains larkspur (Delphinium geyeri Greene) often poison cattle grazing on western North American rangelands. The dominant toxic alkaloid in larkspur is methyllycaconitine (MLA); other very toxic alkaloids in low and plains larkspurs are nudicauline and geyerline. Toxic alkaloid concentrations in larkspur near or above 3 mg ? g 21 present significant risk to grazing cattle. D. nuttallianum from Utah and Colorado, D. andersonii from northern Arizona, and plains larkspur (D. geyeri) from Wyoming were collected for analysis. Concentrations of MLA in D. nuttallianum ranged from 0.8 to 4.5 mg ? g 21 in Utah and Colorado; total toxic alkaloid concentrations were often above 3 mg ? g 21. D. nuttallianum differed (P 5 0.09) in MLA concentration between locations but not phenological stages (P 5 0.41). Concentrations of nudicauline ranged from 0.7 to 4 mg ? g 21 in D. nuttallianum and were different (P 5 0.01) between locations and phenological stages (P 5 0.004). D. andersonii was consistently toxic because the total toxic alkaloid concentration fluctuated from 3 to 6 mg ? g 21 over the growing season. The concentration of geyerline in D. andersonii was equal to or greater than MLA at each phenological stage, thus adding to the toxicity. The concentration of toxic alkaloids in D. geyeri was typically highest (2-4 mg ? g 21) in immature plants, although toxic alkaloid concentrations in plants during the pod stage of growth sometimes increased. Only trace amounts of nudicauline were found in D. geyeri, as most of the alkaloid fraction was other N-(methylsuccinimido) anthranoyllycoctonine (MSAL) alkaloids. Total alkaloid concentration (MSAL and non-MSAL alkaloids) in D. geyeri sometimes exceeded 15 mg ? g 21. Concentrations of toxic alkaloids in D. nuttalliunum, D. andersonii, and D. geyeri often did not significantly decline during the growing season as typically found in tall larkspurs. Thus, risk to grazing cattle may remain high until these plants are dormant. Resumen El ''Low larkspurs'' (Delphinium nuttalliunum Pritz., Delphinium andersonii Gray) y ''Plains larkspur'' (Delphinium geyeri Greene) a menudo envenenan el ganado que apacienta los pastizales del oeste de Norte América. El alcaloide tóxico dominante en ''Larkspur'' es metilicacontina (MLA); otros alcaloides muy tóxicos presentes en ''Low larkspurs'' y ''Plains larkspur'' son nudicaulina y geierlina. En ''Larkspur'', las concentraciones de alcaloides tóxicos cercanas o superiores a 3 mg ? g 21 presentan un riesgo significativo para el ganado en apacentamiento. D. nuttallianum de Utah y Colorado, D. andersonii del norte de Arizona y ''Plains larkspur'' (D. geyeri) de Wyoming se colectaron para análisis. Las concentraciones de MLA en D. nuttallianum fluctuaron de 0.8 a 4.5 mg ? g 21 en Utah y Colorado; las concentraciones totales de alcaloides tóxicos a menudo fueron superiores a 3 mg ? g 21. La concentración de MLA en D. nuttallianum difirió (P 5 0.09) entre localidades, pero no entre...

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Section: Discussionmentioning

confidence: 99%

Toxic Alkaloid Concentrations in Delphinium Nuttallianum, Delphinium Andersonii, and Delphinium Geyeri in the Intermountain Region

Gardner

Pfister

2007

Rangeland Ecology & Management

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“…Even Stewart recognized that it was impossible for the government to approve the action, and this was probably what Benn meant in his memoirs when he talked of 'something of a consensus'. 87 At the beginning of the debate, Michael Foot questioned the legal validity of Nixon's decision and used the analogy of British policy in the Middle East, which had always been that violations by one party did not justify violations by the other. 88 The same point was later repeated in relation to Nixon's apparent escalation of the war: 'True, the law sometimes allows one offence to cancel out another, but only if restraint and proportionality are applied.'…”

Section: The Commons Debate Of 5 Maymentioning

confidence: 99%

Britain and the Cambodian Crisis of Spring 1970

Banks

2005

Cold War History

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Exploiting recently released archival evidence, alongside a series of published primary and secondary literature, this article focuses on the way the British government reacted to President Nixon's apparent escalation of the Vietnam War when he ordered the American and South Vietnamese 'incursion' into Cambodia. Following an exposition of some of the background events, the British policy and reaction towards Nixon's decision is analyzed in depth, looking at how and why Britain was not adequately informed about the operation, and revealing how the Cabinet and Labour Party reacted both in private and in the public domain of the House of Commons towards the Cambodian crisis.British policy towards the Vietnam War, especially during the premiership of Harold Wilson (1964-70) has been of interest to historians in recent years. This is not surprising given the opening of archives of the key years of the Vietnam conflict in the mid-1960s, and the general role of British policy in this period is well understood. Britain and the Soviet Union were the co-chairs of the 1954 Geneva conference that divided Vietnam between North and South. This gave both countries responsibility for

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Terpenoid and Steroid Alkaloids

Robinson

1981

Molecular Biology Biochemistry and Biophysics

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The biosynthesis of diterpenoid alkaloids

Cited by 16 publications

References 6 publications

Toxic Alkaloid Concentrations in Delphinium Nuttallianum, Delphinium Andersonii, and Delphinium Geyeri in the Intermountain Region

Toxic Alkaloid Concentrations in Delphinium Nuttallianum, Delphinium Andersonii, and Delphinium Geyeri in the Intermountain Region

Britain and the Cambodian Crisis of Spring 1970

Terpenoid and Steroid Alkaloids

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