Localization and Catabolism of Cyanogenic Glycosides

Poulton, Jonathan E.

doi:10.1002/9780470513712.ch6

Cited by 39 publications

(15 citation statements)

References 31 publications

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“…25 Figure 124.1 demonstrates these two pathways. Depending on the plant species, two distinct pathways involve 1) the hydrolysis of cyanogenic disaccharides by the stepwise removal of the sugar residues, and 2) hydrolysis of the aglycone -disaccharide bond producing mandelonitrile and the corresponding disaccharides.…”

Section: Biotransformation/eliminationmentioning

confidence: 99%

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Cyanogenic Plants and Laetrile®

Barceloux

2008

Medical Toxicology of Natural Substances

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Section: Biotransformation/eliminationmentioning

confidence: 99%

“…25 Hydroxynitrile compounds may decompose either spontaneously or enzymically in the presence of a hydroxynitrile lyase to produce hydrogen cyanide and an aldehyde or ketone. Hydroxylation of nitriles to α -hydroxynitrile followed by glycosylation forms the cyanogenic glycosides.…”

Section: Mechanism Of Toxicitymentioning

confidence: 99%

Cyanogenic Plants and Laetrile®

Barceloux

2008

Medical Toxicology of Natural Substances

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“…42 Figure 5.1 demonstrates these two pathways. Depending on the plant species, there are two distinct pathways that involve 1) the hydrolysis of cyanogenic disaccharides by the stepwise removal of the sugar residues, and 2) hydrolysis of the aglycone -disaccharide bond producing mandelonitrile and the corresponding disaccharides.…”

Section: Biotransformation/eliminationmentioning

confidence: 99%

“…Many of these cyanogenic glycosides are structurally similar to prunasin including amygdalin (Rosaceae), sambunigrin (Caprifoliaceae, Mimosaceae, Oleaceae), and vicianin (Fabaceae, Polypodiaceae) as demonstrated in Table 5.1 . 7 Hydroxynitrile compounds may decompose either spontaneously or enzymically in the presence of a hydroxynitrile lyase to produce hydrogen cyanide and an aldehyde or ketone. Linamarin and lotaustralin are derivatives of valine, isoleucine and leucine, whereas prunasin, amygdalin, and sambunigrin are derivatives of phenylalanine.…”

Section: Structure and Propertiesmentioning

confidence: 99%

Cyanogenic Foods (Cassava, Fruit Kernels, and Cycad Seeds)

2008

Medical Toxicology of Natural Substances

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HISTORYCassava is a staple in Africa that contains toxic concentrations of cyanogenic glycosides when improperly processed. Occasionally, outbreaks of cyanide poisoning occur following the consumption of bitter cassava, particularly during periods of drought. 1 BOTANICAL DESCRIPTIONThe distribution of cyanogenic glycosides is widespread throughout the plant kingdom, occurring in at least 2,500 plants species, primarily in the Compositae, Fabaceae, Linaceae, and Rosaceae families. 2 Of these plants, clinically important human toxicity probably occurs only following the ingestion of cassava. Prunasin occurs in at least six plant families (Myoporaceae, Myrtaceae, Polypodiaceae, Rosaceae, Saxifragaceae, Scrophulariaceae). CassavaCommon Name : Cassava Scientifi c Name : Manihot esculenta Crantz Botanical Family : Euphorbiaceae (Spurge) Physical Description : Cassava is a perennial, woody shrub with large, brown, tapered tubers that are staples in many poor countries. This shrub or small tree reaches about 1.25 -5 m (4 -16 ft) in height. The leaves are glabrous and deeply parted with spatulate to linear -lanceolate acuminate lobes up to 15 cm (6 in.) long. The fl owers form panicles. Distribution and Ecology : This plant is a native species of Central and South America that was spread by 17th century explorers to Africa and later to the Indian subcontinent. Cassava is widely cultivated in subtropical and tropical areas for the high starch content of the tubers. Fruit Kernels ( Prunus spp. ) Common Name : Apple Scientifi c Name : Malus domestica Borkh. Botanical Family : Rosaceae (rose) Physical Description : This deciduous fruit tree forms a broad crown and reaches up to 12 m (39 ft) in height. The leaves are simple and alternate with a serrated tip and petiole up to 5 cm (2 in.) long. The white fl ower appears in spring with fi ve petals. The fruit matures in autumn with fi ve, star -shaped carpels containing one or two seeds. Distribution and Ecology : The apple is a native plant of the mountains in Central Asia, and now numerous cultivars of the apple are widely distributed throughout the world. Common Name : Peach Scientifi c Name : Prunus persica (L.) Batsch. Botanical Family : Rosaceae (rose) Physical Description : The deciduous tree reaches up to 10 m (33 ft) in height with broad, lanceolate leaves up to 15 cm (6 in.) long. In early spring, the solitary, pink fl owers appear before the leaves with fi ve petals. The drupe (stone fruit) contains a single, large seed with a hard, corrugated cover. Chapter 5 CYANOGENIC FOODS 45Distribution and Ecology : This peach tree is a native species of China, which is now widely cultivated in temperate climates. However, the chilling requirements and limited cold tolerance of the fruit restricts the areas of production to places other than tropical and subtropical climates. Cycad SeedsCycas plants (e.g., Cycas revoluta Thunb. or sago palm) belong to the order Cycadales, which contains approximately 11 genera of tropical and subtropical plants that produce terminal oblong cones...

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“…[1][2][3] These enzymes can also be used for stereoselective synthesis of a wide array of chiral cyanohydrins by the addition of HCN to aldehydes or ketones. Hence more attention is paid to them due to their potential use as catalysts for chiral pharmaceutical intermediates.…”

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confidence: 99%

Expression of Hydroxynitrile Lyase fromManihot esculentain Yeast and Its Application in (S)-Mandelonitrile Production Using an Immobilized Enzyme Reactor

Semba

Dobashi

Matsui

2008

Bioscience, Biotechnology, and Biochemistry

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Hydroxynitrile lyase from cassava, Manihot esculenta (MeHNL), catalyzes the formation of (S)-cyanohydrins from HCN and aldehydes or ketones. (S)-Mandelonitrile was produced on a bench scale with immobilized MeHNL, after optimizing the enzyme expression system using recombinant technology. MeHNL was cloned from a cDNA library prepared from a leaf of Manihot esculenta, and then expressed in a multi-auxotrophic mutant of Saccharomyces cerevisiae cells. The maximum yield of active MeHNL was obtained by integrating transformation 4 times with a tandemly repeated expression cassette. Silica gel was the most suitable support for immobilization of the prepared enzyme from the recombinant yeast. Using this immobilized enzyme, 22 batches of (S)-mandelonitrile synthesis were performed in a 20 liters bioreactor (1 M benzaldehyde and 1.5 M HCN). During this operation, about 29 kg of (S)-mandelonitrile was produced from 23.3 kg of benzaldehyde, giving 98 mol % yield and a mean enantio excess of 98.9% ee.

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Localization and Catabolism of Cyanogenic Glycosides

Cited by 39 publications

References 31 publications

Cyanogenic Plants and Laetrile®

Cyanogenic Plants and Laetrile®

Cyanogenic Foods (Cassava, Fruit Kernels, and Cycad Seeds)

Expression of Hydroxynitrile Lyase fromManihot esculentain Yeast and Its Application in (S)-Mandelonitrile Production Using an Immobilized Enzyme Reactor

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