Showing papers on "Mimosine published in 1979"
TL;DR: It was concluded that DHP is a potent antithyroid compound of the thiouracil type with low general toxicity, since mammals can tolerate a level of intake sufficient to produce goitre in spite of iodine supplementation.
Abstract: Mice fed a diet containing 1% (w/w) 3-hydroxy-4(1H)-pyridone (DHP) developed goitre even with a diet high in iodine whereas mimosine (0.5% w/w) did not produce goitre even with a low-iodine diet. Thyroid enlargement was apparent (measured morphometrically) by the 7th week and was advanced by the 11th week. Histologically the goitre was hyperplastic in type. No marked histological changes were found in other organs of mice fed DHP or any organs of mice fed mimosine, except for some atrophy of hair follicles. A single intragastric dose of DHP inhibited the uptake of 125I by the thyroid in the rat but an equivalent dose of mimosine did not. Evidence is presented that the inhibition occurs at the iodine binding step, as with methyl thiouracil, rather than at the iodide trapping step, as with thiocyanate. Chronic treatment of mice with DHP, as with 6-methyl thiouracil, increased the avidity of the thyroid in taking up 125I. The major conjugated form of DHP in mammals, DHP-3-O-glucuronide, was almost as effective a goitrogen as the unconjugated compound when given by mouth but considerably less active than the free form in the blood stream. It was concluded that DHP is a potent antithyroid compound of the thiouracil type with low general toxicity, since mammals can tolerate a level of intake sufficient to produce goitre in spite of iodine supplementation.
67 citations
01 Jan 1979
TL;DR: The uses of the tropical legume Leucaena leucocephala are quite versatile, but the nutritive potential of this plant is still not fully realized, partly due to the presence of the alkaloid Mimosine in the plant.
Abstract: The uses of the tropical legume Leucaena leucocephala are quite versatile. These uses include its function as a source of firewood and timber,its role in soil erosion control (Dijkman 1950), its ability to provide shade for other plants as well as its function in maintaining the fertility of the soil and of serving as a nutritious forage for animal feed (Ruskln 1977). Presently the greatest use of this plant in animal nutrition is its incorporation in cattle feed. Leucaena leaf-meal, with its rich protein, minerals and vitamin content, is also becoming a popular ingredient in poultry feeds in the tropics (D'Mello and Taplin 1978). However, the nutritive potential of this plant is still not fully realized, partly due to the presence of the alkaloid Mimosine in the plant. In livestock, as well as in experimental animals Mimosine is believed to induce alopecia, growth retardation, goitre, cataract, decreased fertility and mortality. Many investigations relating to the nutritive and toxic aspects of this tropical plant have been reported. It seems appropriate to review and discuss some of these latest findings concerning Leucaena leucocephala.
50 citations
TL;DR: Complex formation of the biologically active amino acid L-mimosine [α-amino-β-(3-hydroxy-4-oxo-1,4-dihydropyridin-1-yl)propanoic acid (1)], mimosinic acid (2), mimosine methyl ether (9) and 3-hydrox-1]-1-methylpyrin-4(1H)-one (4) with Cu2+, Zn2+, Cd2+ and Pb2+ was studied as mentioned in this paper
Abstract: Complex formation of the biologically active amino acid L-mimosine [α-amino-β-(3-hydroxy-4-oxo-1,4-dihydropyridin-1-yl)propanoic acid (1)], mimosinic acid (2), mimosine methyl ether (9) and 3-hydroxy-1-methylpyridin-4(1H)-one (4) with Cu2+, Zn2+, Cd2+ and Pb2+ was studied. Stability constants were determined by potentiometric titration in 0.15M KNOB3 as inert electrolyte at 37o. In the monomeric complexes formed by the mimosine derivatives, metal binding by the hydroxypyridone moiety was favoured relative to the amino acid group. With mimosine, dimeric complexes were major species. Under physiological conditions, mimosine binds copper and zinc ions more strongly than do simpler amino acids.
33 citations
01 Jan 1979
TL;DR: A growing rata consiming diets containing 25% Leucaena leucocephalla meal (equivalent to 0.722 mimosine in the diet) suffered from mild alopecia, reversible paralysis of the hind limbs, severe retardation of growth and mortality as mentioned in this paper.
Abstract: Growing rata consiming diets containing 25% Leucaena leucocephalla meal (equivalent to 0.722 mimosine in the diet) suffered from mild alopecia. cataracts, reversible paralysis of the hind limbs, severe retardation of growth and mortality. Whereas addition of ferrous sulphate (2%) to the ration protected the animals from developing these toxic symptoms; dry heat treatment of the Leucaena meal (at 90~C for 20 hrs) failed to produce a similar result.
11 citations
Journal Article•
TL;DR: DNA, mimosine and DNA polymerase may form a ternary complex that blocks both DNA and RNA syntheses; however, failure of TTP to reverse Mimosine inhibition suggests that unknown factors may be involved.
Abstract: The amino acid mimosine completely inhibited cell division in Paramecium tetraurelia at submillimolar concentrations; DNA, RNA and protein syntheses were all found to be inhibited by mimosine. Mimosine9s effect on cell division was reversible after 48 hours exposure but irreversible after 96 hours of exposure. Thymidine-59-triphosphate was unable to protect Paramecium against the effects of mimosine. Binding of mimosine to purified DNA could not be demonstrated using either equilibrium dialysis or linear dichroic spectral ratios; the presence of 0.025 mM mimosine, however, caused temperature dependent abosrbance profiles of DNA to show a 3% hyperchromicity at 40° (1 x SSC, 250 nm) and an 8% hypochromicity after melting (above 80°). Adding mimosine to an in vitro DNA polymerase system resulted in a 30% to 50% reduction of nucleotide incorporation. DNA, mimosine and DNA polymerase may form a ternary complex that blocks both DNA and RNA syntheses; however, failure of TTP to reverse mimosine inhibition suggests that unknown factors may be involved.
8 citations
01 Jan 1979
TL;DR: Findings revealed that soaking the leaves in water was highly efficient for the extraction of mimosine, the longer the duration of soaking the more mimosines were extracted and juveniles Penaeus monodon fed with diets containing L. leucocephala leaves survived.
Abstract: The study aimed to find a cheap and practical method of extracting mimosine from Leucaena leucocephala, otherwise known as ipil-ipil in the Philippines. L. leucocephala leaves are used in cattle, poultry and swine feed and have been tried as a food ingredient in some fish diets. While it contains relatively high amount of protein, its use as feed has been limited because of the presence of toxic substance, mimosine. Findings revealed that soaking the leaves in water was highly efficient for the extraction of mimosine, the longer the duration of soaking the more mimosine was extracted. On the other hand, 87 % of the juveniles Penaeus monodon fed with diets containing L. leucocephala leaves soaked for 24 hours survived, much higher compared to those that were fed with unsoaked leaves for eight weeks.
5 citations
01 Jan 1979
TL;DR: In this article, the authors reported that leucena gluucu Bentham (Leguminosae) seeds were obtained from Hawaii and were obtained with a view to cultivate the plant on a piece of land.
Abstract: Leucaena gluucu Bentham (Leguminosae) is reported to be toxic: cattle fed with its leaves suffer from loss of their hair and from skin disorders. No systematic work appears to have been carried out with the seed, although the toxicity of the seeds is considered to be due to the presence of mimosine.' An amino acid, 5-hydroxy pipecolic acid2 was reported to be present in the free state in the seed. The present investigation was carried out with the seeds obtained from Hawaii. The seeds were procured with a view to cultivate the plant on a piece of land. The seeds (average wt. 35mg and size 7mm x 4mm) were shiny, flat and oblong, difficult to decorticate. Analysis: moisture, 4.7%; carbohydrate (total) 45%; protein 31.9% (nitrogen 5.1%), and fat 6.2%. The freshly pulverised seeds (900g) were successively extracted with petrol-ether and ethanol. The petroleum ether extract was 6.5% whereas the ethanol extract was 1.3%. The residual meal yielded 6.6% water soluble gummy material. The crude fat had the following characteristics: Colour (Lovibond. 1 cm, 7.5 R, 27.4 Y); iodine value, 122; saponification value, 192; acid value, 6.4; and alcohol-soluble matter 33 'Yo. The alcohol-soluble material appeared to be mostly carbohydrate accompanied by some phenolic constituents and free amino acids. It showed UV absorption at 283 nm (cf. ultra voilet absorption of leucenol at 282nm4). The alcoholic extract freed of petrol ether-soluble fractions of the seed material yielded a sterol, m.p. 138-139'; acetate, m.p. 129', (C, 82.4; H, 11.23%; Calcd. for C31HszOz: C,81; 48; H, 11.4%) and benzoate (benzoyl chloride-pyridine), m.p. 142°C (C, 83.32; H, 10.40; Calcd. for C36Hs40z; C, 83.39; H, 10.42%), which was found to be identical with p-sitosterol by its IR spectra superposable with that of an authentic sample.
2 citations
TL;DR: In this paper, the synthesis of DL-α-amino-β-(4-hydroxy-5oxocyclohepta-1,3,6-trienyl)propanoic acid and its corresponding 6-hydroxyl isomer were described.
Abstract: The synthesis of DL-α-amino-β-(4-hydroxy-5-oxocyclohepta-1,3,6-trienyl)propanoic acid (2) and the corresponding 6-hydroxy isomer (3), tropolone analogues of the wool-growth inhibiting amino acid mimosine (1),is described. Both isomers were obtained in a single sequence, commencing with the cycloaddition of dichloroketene to (β, β-diethoxyethyl)cyclopentadiene, and were readily separated at an intermediate stage via the copper complexes.
2 citations