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Author

A.M. Scofield

Other affiliations: Royal Botanic Gardens
Bio: A.M. Scofield is an academic researcher from University of London. The author has contributed to research in topics: Castanospermine & Hydroxymethyl. The author has an hindex of 13, co-authored 18 publications receiving 674 citations. Previous affiliations of A.M. Scofield include Royal Botanic Gardens.

Papers
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Journal ArticleDOI
TL;DR: Several polyhydroxy alkaloids, including the eight presently known to occur in plants, have been compared as inhibitors of mouse gut digestive disaccharidases and the indolizidine castanospermine inhibited all activities tested, but others showed a selectivity which could be of value in studies of carbohydrate digestion and errors of metabolism.

132 citations

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TL;DR: The isolation from Alexa leiopetala and identification by X-ray crystal structure analysis of (1R,2R,3R,4R,5S,6S)-2-hydroxymethyl-1-azabicyclo[3.3.0]octan-3,4,6-triol], a unique pyrrolizidine alkaloid, is described in this paper.

117 citations

Journal ArticleDOI
TL;DR: The isolation of α-homonojirimycin from Omphalea diandra is described and it is shown that this compound is an inhibitor of several α-glucosidases.

89 citations

Journal ArticleDOI
TL;DR: Two new alexines have been isolated from Castanospermum australe and the structure of 1 7a-diepialexine was firmly established by X-ray crystallographic analysis of the corresponding 1,7-isopropylidene derivative as discussed by the authors.

76 citations

Journal ArticleDOI
TL;DR: In this paper, the isolation from Castanospermum australe and identification by X-ray crystal structure analysis of (1R,2R,3S,7S,8R)-3-hydroxymethyl-1,2,7-trihydroxypyrrolizidine [(2S,3R,4R,5S,6R)-2-hydronymethyl]-1-azabicyclo[3.3.0]octan-3,4,6-triol], the second example of a p

60 citations


Cited by
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Book
01 Jan 1998
TL;DR: The mechanisms underlying plant resistance to invading herbivores on the one side, and insect food specialization on the other, are the main subjects of this book.
Abstract: Half of all insect species are dependent on living plant tissues, consuming about 10% of plant annual production in natural habitats and an even greater percentage in agricultural systems, despite sophisticated control measures. Plants are generally remarkably well-protected against insect attack, with the result that most insects are highly specialized feeders. The mechanisms underlying plant resistance to invading herbivores on the one side, and insect food specialization on the other, are the main subjects of this book. For insects these include food-plant selection and the complex sensory processes involved, with their implications for learning and nutritional physiology, as well as the endocrinological spects of life cycle synchronization with host plant phenology. In the case of plants exposed to insect herbivores, they include the activation of defence systems in order to minimize damage, as well as the emission of chemical signals that may attract natural enemies of the invading herbivores and maybe exploited by neighbouring plants that mount defences as well.

1,857 citations

Journal ArticleDOI
TL;DR: A review of historically significant bioactive marine and terrestrial natural products, their use in folklore and dereplication techniques to rapidly facilitate their discovery, and a discussion of how natural product chemistry has resulted in the identification of many drug candidates are highlighted.
Abstract: Historically, natural products have been used since ancient times and in folklore for the treatment of many diseases and illnesses. Classical natural product chemistry methodologies enabled a vast array of bioactive secondary metabolites from terrestrial and marine sources to be discovered. Many of these natural products have gone on to become current drug candidates. This brief review aims to highlight historically significant bioactive marine and terrestrial natural products, their use in folklore and dereplication techniques to rapidly facilitate their discovery. Furthermore a discussion of how natural product chemistry has resulted in the identification of many drug candidates; the application of advanced hyphenated spectroscopic techniques to aid in their discovery, the future of natural product chemistry and finally adopting metabolomic profiling and dereplication approaches for the comprehensive study of natural product extracts will be discussed.

1,282 citations

Journal ArticleDOI
TL;DR: The structural basis for the specificity of inhibition of alkaloidal sugar mimics and their current and potential application to biomedical problems will be reviewed.
Abstract: Alkaloids mimicking the structures of monosaccharides are now believed to be widespread in plants and microorganisms, and these sugar mimics inhibit glycosidases because of a structural resemblance to the sugar moiety of the natural substrate. Naturally occurring sugar mimics with a nitrogen in the ring are classified into five structural classes: polyhydroxylated piperidines, pyrrolidines, indolizidines, pyrrolizidines and nortropanes. Glycosidases are involved in a wide range of important biological processes, such as intestinal digestion, post-translational processing of glycoproteins and the lysosomal catabolism of glycoconjugates. The realization that alkaloidal sugar mimics might have enormous therapeutic potential in many diseases such as viral infection, cancer and diabetes has led to increasing interest and demand for these compounds. Most of these effects can be shown to result from the direct or indirect inhibition of glycosidases. The glycosphingolipid (GSL) storage diseases are relatively rare hereditary disorders that are severe in nature and frequently fatal. Possible strategies for the treatment of these lysosomal storage diseases include enzyme replacement therapy, gene therapy and substrate deprivation. Recently, quite a new therapy for lysosomal storage diseases has been reported, namely a ‘chemical chaperone therapy’ for Fabry disease. In this report, the structural basis for the specificity of inhibition of alkaloidal sugar mimics and their current and potential application to biomedical problems will be reviewed.

881 citations

Journal ArticleDOI
TL;DR: Over one hundred polyhydroxylated alkaloids have been isolated from plants and micro-organisms, and only three of the natural products so far have been widely studied for therapeutic potential due largely to the limited commercial availability of the other compounds.

643 citations

Journal ArticleDOI
Ritsuo Nishida1
TL;DR: The biochemical, physiological, and ecological characteristics of phytochemical-based defense systems that can shed light on the evolution of the widely developed sequestering lifestyles among the Lepidoptera are illustrated.
Abstract: A number of aposematic butterfly and diurnal moth species sequester unpalatable or toxic substances from their host plants rather than manufacturing their own defensive substances. Despite a great diversity in their life histories, there are some general features in the selective utilization of plant secondary metabolites to achieve effective protection from predators. This review illustrates the biochemical, physiological, and ecological characteristics of phytochemical-based defense systems that can shed light on the evolution of the widely developed sequestering lifestyles among the Lepidoptera.

564 citations