Pyrrolizidine Alkaloids

Plants containing pyrrolizidine alkaloids are so numerous and widespread that they can be expected to be present in most environments. About 200 pyrrolizidine alkaloids have been isolated and identified from different plants. Interest in these alkaloids has increased in recent years due to their causative effects in the heavy loss of livestock in many countries. Naturally Occurring Pyrrolizidine Alkaloids discusses the plant sources and properties of pyrrolizidine alkaloids; extraction, fractionation and identification; various methods of spectrometry of pyrrolizidine alkaloids; quantitative determination; and the toxicity, carcinogenicity, pharmacology, and other biological activities of pyrrolizidine alkaloids. Researchers in veterinary and human medicine will find this book to be a fascinating and useful reference tool.

This is a companion volume to Environmental Health Criteria 80: Pyrrolizidine alkaloids. Published by WHO for the International Programme on Chemical Safety, (a collaborative programme of UNEP, ILO and WHO)

Pyrrolizidine alkaloids show only minor toxicity in their native state, but are metabolized in the human or animal organisms to carcinogenic, teratogenic and mutagenic compounds, with the precise structure of these compounds being responsible for the metabolic toxification process. Therefore, to be able to evaluate the toxic potential of each alkaloid, it is essential to exactly know the structure of the respective compound. X-ray structure analysis is the appropriate method both for elucidating the structure and for determining other parameters, such as the lengths of the bonds that influence the metabolic process. This book describes the incidence and the process of the intoxication as well as the possibilities to how the substances may reach the organism. In addition, the compounds elucidated by X-ray structure analysis to date are shown in their three-dimensional structure and structure-toxicity relationships are discussed.Pyrrolizidinalkaloide weisen in nativem Zustand nur geringe Toxizität auf, werden jedoch zu kanzerogenen, teratogenen und mutagenen Verbindungen metabolisiert, wenn sie in den menschlichen oder tierischen Organismus gelangen. Der Verlauf dieser Toxifizierung hängt von der konkreten Struktur dieser Stoffe und weiteren Parametern ab. Zur Bestimmung dieser Faktoren stellt die Röntgenstrukturanalyse die geeignete Methode dar. Im vorliegenden Buch werden das Vorkommen, der Ablauf der Toxifizierung und die Möglichkeiten, wie die Stoffe in den Organismus gelangen können, beschrieben. Es werden die bislang durch Röntgenstrukturanalyse vermessenen Verbindungen in ihrer 3D-Struktur aufgefÃ"hrt und Struktur-Toxizitätsbeziehungen diskutiert.

Analysis of Food Toxins and Toxicants consists of five sections, providing up-to-date descriptions of the analytical approaches used to detect a range of food toxins. Part I reviews the recent developments in analytical technology including sample pre-treatment and food additives. Part II covers the novel analysis of microbial and plant toxins including plant pyrrolizidine alkaloids. Part III focuses on marine toxins in fish and shellfish. Part IV discusses biogenic amines and common food toxicants, such as pesticides and heavy metals. Part V summarizes quality assurance and the recent developments in regulatory limits for toxins, toxicants and allergens, including discussions on laboratory accreditation and reference materials.

Herbal medicinal products are becoming more widely accepted as alternatives to medical prescriptions. Many physicians believe that herbal medicinal products are able to beneficially complement or even replace chemical medicines. Recognizing this, European institutions are pushing the harmonization of assessment criteria for herbal medicinal products. However, this kind of reevaluation of herbal medicinal products is combined with increased expectations of physicians, pharmacists, and patients with regard to quality, safety and efficacy. There are often uncertainties about the interpretation of basic terms related to the manufacture and quality of herbal medicinal products. Herbal Medicinal Products clarifies these uncertainties, increasing transparency in the herbal medicinal products market and supporting an adequate scientific discussion related to herbal medicinal products. It offers a complete survey on current scientific knowledge, as well as on legal basic requirements for the development, standardization, and licensing of herbal medicinal products.