نتایج جستجو برای: pyrrolizidine alkaloids

تعداد نتایج: 14689  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1999
V K Iyengar T Eisner

In Utetheisa ornatrix (Lepidoptera, Arctiidae), the female mates preferentially with larger males. Having a larger father results in the eggs being more richly endowed with defensive pyrrolizidine alkaloid (which the female receives from the male with the sperm package, in quantity proportional to the male's body mass, and passes on to the eggs); having a larger father also results in the sons ...

A. Shafiee H. Farsam M. Banihashem M. R. Delnavazi N. Yassa

Background and objectives: The plants belonging to the genus Heliotropium L. (Boraginaceae) are the main sources of toxic pyrrolizidine alkaloids (PAs). In the present study, we have investigated the PAs of the aerial parts of Heliotropium transoxanum Bunge, a perennial species native to Iran. Methods: Silica gel column chromatography and silica gel PTLC were applied ...

Journal: :South African Journal of Botany 2021

Pyrrolizidine alkaloids (PAs) are amino alcohols, often esterified with mono- or dicarboxylic acids, found in several plant families, including the Asteraceae. used for defence against generalist invertebrate herbivores. However, specialist herbivores that able to sequester PAs from host species derive a number of benefits these compounds. This study investigated and leaves roots southern Afric...

2010
Sven Sehlmeyer Linzhu Wang Dorothee Langel David G. Heckel Hoda Mohagheghi Georg Petschenka Dietrich Ober

Insects experience a wide array of chemical pressures from plant allelochemicals and pesticides and have developed several effective counterstrategies to cope with such toxins. Among these, cytochrome P450 monooxygenases are crucial in plant-insect interactions. Flavin-dependent monooxygenases (FMOs) seem not to play a central role in xenobiotic detoxification in insects, in contrast to mammals...

Journal: :Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment 2011
A Dübecke G Beckh C Lüllmann

A total of 3917 honey samples and 119 'bee pollen' samples (pollen collected by honeybees) were analysed for pyrrolizidine alkaloids (PAs). Some 0.05 M sulphuric acid was used for extraction followed by a clean-up step by means of solid-phase extraction. Separation and detection was achieved by target analysis using an LC-MS/MS system. PAs were found in 66% of the raw honeys (bulk honey not yet...

Journal: :Journal of dairy science 1993
M L Westendorf G E Mitchell R E Tucker L P Bush R J Petroski R G Powell

Relationships between alkaloid compounds in endophyte-infected tall fescue and ruminal metabolism were studied in two experiments. In the first experiment, different combinations of the pyrrolizidine alkaloids, N-formyl and N-acetyl loline, were incubated with ruminal fluid for 0, 24, or 48 h. Rate of disappearance of N-formyl and N-acetyl loline increased over time. After 48 h, disappearance o...

Journal: :Public health nutrition 2000
F Stickel H K Seitz

Herbal medication has gathered increasing recognition in recent years with regard to both treatment options and health hazards. Pyrrolizidine alkaloids have been associated with substantial toxicity after their ingestion as tea and in the setting of contaminated cereals have led to endemic outbreaks in Jamaica, India and Afghanistan. In Western Europe, comfrey has been applied for inflammatory ...

Journal: :Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment 2011
H Wiedenfeld

Pyrrolizidine alkaloids (PA) are toxic for human and livestock. They undergo a metabolic toxication process in the liver which is the first target organ for PA poisoning. Worldwide many episodes of human PA intoxications are well reported. In many cases the reason for these intoxications has been PA contamination in food. The main tools for analysing food and fodder on PA content are based on G...

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