Free amino acids in the seeds of Acacia species

Free amino acids in the seeds of 80 species of Acacia have been determined. In addition to confirming the known difference in seed amino acid ‘patterns’ shown by species of the series Gummiferae on the one hand and species of the series Phyllodineae and Botryocephalae on the other, we have found that species of the series Vulgares Benth. show two additional ‘patterns’. One of these is common to some of the Afro-Asian species of the series which have been analysed and the other is common to species from America and Africa. One of the ‘marker’ amino acids of the Afro-Asian group is the neurotoxic lathyrogen α-amino-β-oxalylaminopropionic acid. The possible taxonomic and phylogenetic significance of these results is discussed, with special reference to five species A. albida, A. confusa, A. heterophylla, A. coulteri and A. kauaiensis.     

A populational survey of amino acids in Prosopis species from North and South America

Leaf extracts of 540 plants representing 24 species of the genus Prosopis from North and South America were analyzed by 2-D PC and high voltage electrophoresis for their protein and non-protein amino acids. In addition to the presence of the usual protein amino acids, most of the species examined contained high concentrations of the non-protein amino acids, pipecolic acid, 4-hydroxypipecolic acid and proline.     

2-amino-4-acetylaminobutyric acid, 2,4-diaminobutyric acid and 2-amino-6N-oxalylureidopropionic acid (oxalylalbizziine) in seeds of acacia angustissima

A new amino acid previously detected in 17 species of Acacia has been isolated from seeds of Acacia angustissima and identified as oxalylalbizziine. These seeds also contain more than 6% dry weight of 2-amino-4-acetylaminobutyric acid, which has not been reported previously in a legume, and lower concentrations of 2,4-diaminobutyric acid.     

The Effect of Some Protein and Non-Protein Amino Acids on the Growth of Cladosporium herbarum and Trichothecium roseum

The effect of ten amino acids as the sole nitrogen source for the growth of Cladosporium herbarum (Link.) Fr. and Trichothecium roseum (Bull.) Link. was studied in order to clarify the fungus-host plant relationship. Special attention was paid to some rare non-protein amino acids of legumes. The best nitrogen sources for both fungi were γ-aminobutyric acid, arginine, serine and proline. Cladosporium could use homoarginine and canavanine, but these two amino acids were not used by Trichothecium when each was given as the only nitrogen source. Both fungi utilized ornithine, homoserine and a,γ-diaminobutyric acid to a limited extent. Pipecolic acid was not growth promoting. The growth-retarding effects of rare non-protein amino acids (homoarginine, canavanine, a,γ-diaminobutyric acid and pipecolic acid) were usually reversed by higher concentrations of their normal analogues. It is possible that rare non-protein amino acids may slightly protect the host plant against fungal infections, but there are clear differences between fungi in their reaction to non-protein amino acids.     

Toxicity of secondary compounds to the seed-eating larvae of the bruchid beetle Callosobruchus maculatus

By incorporating various secondary compounds in the normal diet of larval Callosobruchus maculatus bruchids, we show that the effects of any particular compound are dosage-dependent. Alkaloids are generally the most toxic of the compounds tested. Non-protein amino acids are more toxic than protein amino acids but the latter can be toxic at 1 and 5% incorporation in the diet. The non-protein amino acid homoarginine has a salutary effect on larval survival at low concentrations. A variety of other secondary compounds found in seeds are toxic at various levels representative of those levels found in seeds in nature, and for all secondary compounds tested a 0.1–5% incorporation in the diet often has a detrimental effect on production of adult beetles. We conclude that many of the secondary compounds found in seeds are likely to be toxic to at least some animal, and thus are likely to be responsible at least in part for the extreme host-specifity shown by seed-eating insects.     

Etude chimiotaxonomique dans les genres Macrotyloma, Dolichos et Pseudovigna

The variations of free, protein and total amino acid contents have been studied in seeds of Macrotyloma, Dolichos and Pseudovigna. The concentrations of free amino acids and of γ-glutamylphenylalanine seem to be characteristic of some species and also of some genera.     

Brain uptake of pipecolic acid,amino acids,and amines following intracarotid injection in the mouse

The uptake of pipecolic acid by the mouse brain was compared to that of several amino acids and amines, following an injection of a double-labeled mixture into the carotid artery. In general, BUI (brain uptake index) values were lower in the mouse than those previously reported in the rat. The only exception was proline. Lysine, a precursor of pipecolic acid biosynthesis in brain, showed a higher BUI than pipecolic acid. The BUI ofD,l-[³H]pipecolic acid was found to be 3.39 (at 0.114 mM). This was saturable between a concentration of 0.114 and 3.44 mM. Kinetic analysis suggests the presence of two kinds of transport systems. Substances structurally related to pipecolic acid, such as nipecotic acid, isonipecotic acid,l-proline, and piperidine show a significant inhibitory effect. Among the amino acids tested, only GABA showed an inhibitory effect. Data are reported which, when considered with other findings (5), present evidence that pipecolic acid is (1) synthesized both in vitro and in vivo in the mouse brain, (2) actively transported in vivo into the brain, and (3) taken up in vitro by synaptosomal preparations.     

Amino acid and protein changes in the haemolymph of developing fourth instar Chironomus tentans

The concentration of free amino acids, total soluble protein, and haemoglobin in the haemolymph of fourth instar Chironomus tentans was investigated.The concentration of the free amino acid pool increases between the early (15.7 mM/l) and mid-(33.9 mM/l) fourth larval stages followed by a decline during the late (16.9 mM/l) fourth larval period. Alanine, serine, and the amides of aspartic acid and glutamic acid are the predominant free amino acids at all stages. Physiological fluid analysis of late fourth instar haemolymph detected 32 ninhydrin positive components including 18 common amino acids plus homoarginine, ornithine, citrulline, β-alanine, α-aminoadipic acid, α-aminoisobutyric acid, and sarcosine.The concentration of total soluble protein steadily increases during fourth instar larval development to a maximum of $\text{9.3}\text{g}\text{100}\text{ml}$ followed by a decline during the pharate pupal period. A similar pattern of variation occurs in haemoglobin content which comprises from 51 to 66% of Chironomus tentans haemolymph protein.The mM percentage of individual amino acids of total haemolymph protein varies little during the fourth instar. At all stages alanine and aspartic acid are the predominant amino acids.     

三角鲂和长春鳊肌肉营养成分分析与品质评价

用常规方法测定、分析了三角鲂(Megalobrama tarminalis)和长春鳊(Parabramis pekinensis肌肉中营养成分组成与含量.结果显示,三角鲂肌肉蛋白质、脂肪含量分别为18.19％和3.06％,长春鳊肌肉蛋白质、脂肪含量分别为19.38％和2.89％.三角鲂和长春鳊肌肉中均检测出18种氨基酸,其中包括了8种人体必需氨基酸.三角鲂肌肉中氨基酸总量为76.27％,其中,8种人体必需氨基酸含量为32.17％,占氨基酸总量的42.18％;长春鳊肌肉中氨基酸总量为77.60％,其中,8种人体必需氨基酸含量为31.70％,占氨基酸总量的40.85％.必需氨基酸的构成比例基本符合FAO/WHO的标准.三角鲂肌肉中限制性氨基酸主要为甲硫氨酸加胱氨酸,必需氨基酸指数为63.55,4种呈味氨基酸为氨基酸总量的32.81％;长春鳊肌肉中限制性氨基酸主要为色氨酸,必需氨基酸指数为66.81,4种呈味氨基酸为氨基酸总量的33.80％.脂肪酸中二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)含量均较高,三角鲂为7.96％,长春鳊为3.11％.矿物元素比值合理.以上分析表明,三角鲂和长春鳊均为营养价值、经济价值都较高的优质鱼类,相比而言,三角鲂肌肉脂肪、脂肪酸含量和质量更优,而长春鳊肌肉在蛋白质、氨基酸组成与含量方面更优.     

Drought stress increases the production of 5-hydroxynorvaline in two C4 grasses

Plants produce various compounds in response to water deficit. Here, the presence and identification of a drought-inducible non-protein amino acid in the leaves of two C₄ grasses is first reported. The soluble amino acids extracted from the leaves of three different species were measured by high-performance liquid chromatography of derivatives formed with o-phthaldialdehyde and β-mercaptoethanol. One amino acid that increased in amount with drought stress had a retention time not corresponding to any common amino acid. Its identity was determined by metabolite profiling, using ¹H NMR and GC-MS. This unusual amino acid was present in the dehydrated leaves of Cynodon dactylon (L.) Pers. and Zoysia japonica Steudel, but was absent from Paspalum dilatatum Poir. Its identity as 2-amino-5-hydroxypentanoic acid (5-hydroxynorvaline, 5-HNV) was confirmed by synthesis and co-chromatography of synthetic and naturally occurring compounds. The amount of 5-HNV in leaves of the more drought tolerant C₄ grasses, C. dactylon and Z. japonica, increased with increasing water deficit; therefore, any benefits from this unusual non-protein amino acid for drought resistance should be further explored.     

Distribution of imino acids in Ptelea and their probable ecological significance

Seed and leaf extracts of 124 populations of all three species of Ptelea were analysed by paper chromatography and high voltage electrophoresis for their imino acids. Proline and pipecolic acid were found to have a wide distribution in the genus with high concentrations of both imino acids restricted to the xeric forms. The ecological significance is discussed.     

14CO2 dark fixation in the halophytic species mesembryanthemum crystallinum

The time course of ¹⁴CO₂ dark fixation was studied in leaves of the facultatively halophytic plant species Mesembryanthemum crystallinum cultivated with and without 400 mM NaCl in the nutrient medium. It is generally known from the literature that plants grown under saline conditions incorporate ¹⁴C predominately into amino acids. By contrast in leaves of M. crystallinum grown on NaCl and exposed to ¹⁴CO₂ in the dark, relatively more radioactivity is incorporated in the organic acids (especially malate) than in amino acids. The data obtained are discussed in relation to the NaCl induced Crassulacean acid metabolism in M. crystallinum reported earlier.     

Hydroxylated glutamic acids in Phlox,lepidium and Rheum species

The two diastereoisomers, (2S,4R)-4-hydroxyglutamic acid and (2S,4S)-4-hydroxyglutamic acid, occur in characteristic concentration ratios in Phlox species. The second of these compounds is the principal free amino acid in the green parts of the plants. The presence of (2S,4R)-4-hydroxyglutamic acid in plants is reported for the first tiine. No other 4-substituted acidic amino acids were detected in the Phlox species analysed, although special attention was paid to the possible presence of 4-hydroxy-4-methylglutamic acids which have previously been reported in plants. It was found, however, that both diastereoisomers of (2S)-4-hydroxy-4-methylglutamic acid co-exist in Ledenbergia roseoaenea and also in Pandanus veitchii. Although the presence of 3,4-dihydroxyglutamic acids in green parts of Lepidium sativum and Rheum rhaponticum has been previously reported, we were not able to detect or isolate any of the possible diastereoisomers from the green parts or seeds of these plants. We did isolate glutathione which was found to have some properties in common with those reported for the dihydroxy compounds.     

Isoxazolin-5-one derivatives in Lathyrus odoratus during development and growth

Variations in the concentrations of isoxazolin-5-ones and of some non-protein amino acids in the dry seeds, seedlings and various parts of mature Lathyrus odoratus plants were examined. The lathyrogenic compounds α-amino-γ-(isoxazolin-5-on-2-yl)-butyric acid, 2-cyanoethyl-isoxazolin -5-one and γ-glutamyl-β-aminopropionitrile were major products during development and growth.     

Proteinase inhibitors from Erythrina corallodendron and Erythrina cristagalli seeds

Eight and five proteinase inhibitors were purified from Erythrina corallodendron and E. cristagalli seeds, respectively, by gel filtration followed by ion exchange chromatography on DEAE-cellulose and DEAE-sepharose. Each inhibitor consists of 161–163 amino acids (M_r 18 000) including four half-cystine residues and resembles the Kunitz-type proteinase inhibitors. The N-terminal amino acid sequence of trypsin inhibitor DE-7 from E. corallodendron seed resembles those of other Erythrina species. For the other inhibitors no free N-terminal amino acid was found. DE-1,-2,-3,-4 and -5 from the seed of E. corallodendron contain potent inhibitors for α-chymotrypsin and they have practically no action on trypsin. From the same seed, inhibitors DE-6, -7 and -8 strongly inhibit trypsin and also inhibit α-chymotrypsin to varying degrees. From the seeds of E. cristagalli, inhibitors DE-1 and -8 inhibit trypsin strongly and DE-2, -3 and -4 are strongly inhibitory for α-chymotrypsin. On summarizing the inhibitor characteristics of the Kunitz-type proteinase inhibitors from the seeds of eight different species of Erythrina, it was obvious that there is a relationship between the alanine content of the inhibitors and their activities. A high alanine content is associated with potent α-chymotrypsin activities and low alanine content with strong trypsin activities.     

Variability for protein and oil quality in Lupinus albus

Amino acid composition and fatty acid composition were determined on seed samples of a range of white lupin (Lupinus albus) cultivars and accessions grown in either of two environments.Variability between genotypes was found for lysine, arginine and glutamic acid content, but not for the concentrations of other amino acids. The deficiency in sulphurcontaining amino acids, typical of legume proteins, was evident, with methionine and cyst(e)ine totalling only 2.2% of the protein. Variability was limited, indicating that improvement by breeding would be impracticable. Lupinus albus differed slightly from other lupin species in amino acid composition, having higher levels of threonine, tyrosine and isoleucine, but a lower level of glutamic acid than both L. angustifolius and L. luteus. Four low-alkaloid lines of L albus each had higher lysine content than the high-alkaloid line, but ‘Kiev Mutant’, despite earlier claims, had a lysine level no higher than the other three low-alkaloid lines.Fatty acid composition of the seed oil varied considerably between genotypes. Oleic acid ranged from 43.6 to 54.4% and linolenic acid from 6.7 to 15.2%, these two fatty acids being negatively correlated at one site. Linoleic acid content varied between 17.2 and 26.9% and was not correlated with other fatty acids. Total oil content averaged 9.6% with little variability between lines.It is concluded that, relative to other lupin species, L. albus has a more favourable amino acid profile for its utilisation in cereal-based diets for animals, particularly if the energy source is wheat, which is deficient in threonine. The higher oil content would be an important energy benefit to such diets and may allow their protein/energy balance to be maintained at higher levels of incorporation of L. albus seed meal than is possible with other lupin species.     

Cyanogenesis in Acacia pachyphloia

The cyanogenic glycoside, proacacipetalin, is reported from Acacia pachyphloia (Acacia subgenus Acacia). This represents the first record of a glycoside with an aliphatic aglycone from a species of Acacia indigenous to Australia. This finding reinforces the taxonomic distinctions between subgenus Acacia and subgenus Phyllodineae.     

Amino acids of Caesalpinia tinctoria and some allied species

Two previously unreported amino acids have been found to form major constituents of seed of Caesalpinia tinctoria; they have been characterized as 4-hydroxy-3-hydroxymethylphenylalanine and 3-hydroxymethylphenylalanine. The seed also contains a large amount of the imino acid baikiain. The amino acid content of seeds of this species is compared with that for 12 other species of Caesalpinia and 14 species in closely related genera.     

The effect of some non-protein amino acids on pollen germination and pollen-tube growth in five species of the Vicieae

Summary The effects of canavanine, ,-diaminobutyric acid, homoarginine and lathyrine on the germination of pollen and on in-vitro growth of pollen tubes were studied in the following species: Lathyrus niger, L. silvestris, Vicia unijuga, Pisum sativum and Cicer arietinum.The effects of these non-protein amino acids depended on their quantity and on the plant species. Every amino acid had a promoting effect on germination and growth at some concentration in some species. Inhibition or promotion of pollen germination and pollen-tube growth were usually parallel. The stronger influence of some amino acid on growth than on germination may be due to slow penetration of the acid into the cell.Homoarginine and lathyrine had a promoting effect at all concentrations in L. niger, a species in which these amino acids occur naturally. In most other species they had, if anything, a very slight inhibitory effect, ,-Diaminobutyric acid and canavanine had the strongest inhibitory effects on the species studied. It seems possible that these amino acids are antimetabolites of common amino acids.It is obvious that non-protein amino acids can form effective hybridization barries, although the conditions in nature are more complex than in vitro. The ability to synthesize a new amino acid may therefore be of evolutionary significance in the isolation of new species and genera.     

Stimulation of the Po-shen and Shen-hun scalp-acupuncture bands modifies levels of inhibitory and excitatory amino acids in the immature rat brain

Objective

In the present study, the effect of stimulation of the Po-shen and Shen-hun scalp-acupuncture bands on tissue amino acid concentrations in several brain regions in awake and pentobarbital-sedated immature rats was evaluated.

Materials and methods

Sprague–Dawley rats (aged 15 days) were organized in four groups of at least eight animals: control groups received saline solution 0.9% or sodium pentobarbital at 30 mg/kg dosage via intraperitoneal. Experimental groups received saline solution or sodium pentobarbital plus stimulation in Po-shen and Shen-hun scalp-acupuncture bands for one continuous hour during 10 sessions by using scalp-acupuncture.

Results

As compared to rats receiving saline solution, scalp-acupuncture produced significant changes in amino acid concentrations, depending on the analyzed region, as follows: in inhibitory amino acids, a GABA increase was observed in amygdala and hippocampus (491 and 184%, respectively), but a decrease in the substantia nigra (80%); glycine showed decrease in all the analyzed regions, except for an increase in brainstem(78%); glutamine presented an increase in hippocampus and cortex (42 and 149%, respectively). In the case of excitatory amino acids, glutamate decreased in all the analyzed regions; whereas aspartate decreased in substantia nigra and brainstem (77.08 and 35%, correspondingly) but increased in hippocampus and cortex (32 and 54%, respectively). The combined treatment of scalp-acupuncture and a GABAergic depressant drug like pentobarbital resulted in almost all changes induced in amino acids for scalp-acupuncture alone being significantly reverted.

Conclusion

Stimulation of the Po-shen and Shen-hun scalp-acupuncture bands by using scalp-acupuncture alone might produce depressant activity by changes in amino acids, but the combination with a GABAergic tranquilizer like sodium pentobarbital can interfere with this response.