Changes in γ-Methyleneglutamic acid, γ-Methyleneglutamine and other amino acids and amides during fruit growth of Tribulus terrestris

Abstract

Distribution and metabolism of γ-methyleneglutamic acid, γ-methyleneglutamine and other amino acids and amides has been studied during fruit growth of Tribulus terrestris. The largest concentration of free amino acids and amides has been observed in fruit stage 1. The marked decline in the amount of γ-methyleneglutamic acid and γ-methyleneglutamine after fruit stage 1 may indicate their rapid utilization along with asparagine and glutamine during fruit growth. In leaf and in different fruit growth stages, γ-methyleneglutamic acid dominated over γ-methyleneglutamine.     

The influence of Agrobacterium rhizogenes on induction of hairy roots and ß-carboline alkaloids production in Tribulus terrestris L.

We have developed an efficient transformation system for Tribulus terrestris L., an important medicinal plant, using Agrobacterium rhizogenes strains AR15834 and GMI9534 to generate hairy roots. Hairy roots were formed directly from the cut edges of leaf explants 10–14 days after inoculation with the Agrobacterium with highest frequency transformation being 49 %, which was achieved using Agrobacterium rhizogenes AR15834 on hormone-free MS medium after 28 days inoculation. PCR analysis showed that rolB genes of Ri plasmid of A. rhizogenes were integrated and expressed into the genome of transformed hairy roots. Isolated transgenic hairy roots grew rapidly on MS medium supplemented with indole-3-butyric acid. They showed characteristics of transformed roots such as fast growth and high lateral branching in comparison with untransformed roots. Isolated control and transgenic hairy roots grown in liquid medium containing IBA were analyzed to detect ß-carboline alkaloids by High Performance Thin Layer Chromatograghy (HPTLC). Harmine content was estimated to be 1.7 μg g⁻¹ of the dried weight of transgenic hairy root cultures at the end of 50 days of culturing. The transformed roots induced by AR15834 strain, spontaneously, dedifferentiated as callus on MS medium without hormone. Optimum callus induction and shoot regeneration of transformed roots in vitro was achieved on MS medium containing 0.4 mg L⁻¹ naphthaleneacetic acid and 2 mg L⁻¹ 6-benzylaminopurine (BAP) after 50 days. The main objective of this investigation was to establish hairy roots in this plant by using A. rhizogenes to synthesize secondary products at levels comparable to the wild-type roots.     

Saponins and Phylogeny: Example of the “Gypsogenin group” Saponins

The chemical structure of triterpenoid saponins is quite complicated, especially the glucuronide oleanane-type triterpene carboxylic acid 3,28-bidesmosides (GOTCAB) saponins. Moreover, triterpenoid saponins are numerous as a result of this complicated structure. This review tries to explain this diversity in terms of plant classification and phylogeny. The study focuses on the three main successive steps of the biosynthetic pathway of the triterpenoid saponins: cyclisation, oxidation and glycosylation showing the relationship between triterpenols and sterols in terms of cell membrane evolution and the importance of which metabolic intermediates involved as aglycones of the triterpenoid saponins, represented progressively less and less in the advanced groups of the plant kingdom as they are more and more oxidised. This oxidation seems to reflect a better adaptation to new environmental conditions of some of these groups. By their enormous chemical diversity, the triterpenoid saponins seem to be good candidates to study the phylogeny of the flowering plants. A first attempt is given using recent advances in botanical classification for the orders and families by the Angiosperm Phylogenic Group (APG). This study was simplified in the first step focusing only on the “gypsogenin group” of the GOTCAB saponins. For example, as a result, these compounds are mainly concentrated in advanced groups such as Caryophyllideae, primitive Rosideae and Asterideae.     

Effect of Synthetic Auxin Analogs (2.4-D and α-NAA) on Growth and Biosynthetic Characteristics of Suspension Cell Culture of Tribulus terrestris L.

Russian Journal of Plant Physiology - Effect of synthetic analogs of auxins—2.4-dichlorophenoxyacetic (2.4-D) and α-naphthylacetic (α-NAA) acids—on growth characteristics and...     

Potassium in agriculture – Status and perspectives

In this review we summarize factors determining the plant availability of soil potassium (K), the role of K in crop yield formation and product quality, and the dependence of crop stress resistance on K nutrition. Average soil reserves of K are generally large, but most of it is not plant-available. Therefore, crops need to be supplied with soluble K fertilizers, the demand of which is expected to increase significantly, particularly in developing regions of the world. Recent investigations have shown that organic exudates of some bacteria and plant roots play a key role in releasing otherwise unavailable K from K-bearing minerals. Thus, breeding for genotypes that have improved mechanisms to gain access to this fixed K will contribute toward more sustainable agriculture, particularly in cropping systems that do not have access to fertilizer K. In K-deficient crops, the supply of sink organs with photosynthates is impaired, and sugars accumulate in source leaves. This not only affects yield formation, but also quality parameters, for example in wheat, potato and grape. As K has beneficial effects on human health, its concentration in the harvest product is a quality parameter in itself. Owing to its fundamental roles in turgor generation, primary metabolism, and long-distance transport, K plays a prominent role in crop resistance to drought, salinity, high light, or cold as well as resistance to pests and pathogens. Despite the abundance of vital roles of K in crop production, an improvement of K uptake and use efficiency has not been a major focus of conventional or transgenic breeding in the past. In addition, current soil analysis methods for K are insufficient for some common soils, posing the risk of imbalanced fertilization. A stronger prioritization of these areas of research is needed to counter declines in soil fertility and to improve food security.     

THE INSECTICIDES—Their Hazard in Industry and in the Home Part I—Chemistry and Pharmacology

Chemical, pharmacologic and toxicologic properties of the chlorinated hydrocarbon and organic phosphate insecticides have been reviewed. The chlorinated group present problems if there is either acute or chronic exposure, whereas the problems associated with the organic phosphates develop only in event of acute exposure.Chlorinated hydrocarbon insecticides accumulate in body fat depots and cause both liver and kidney damage while being metabolized and excreted. Organic phosphates destroy cholinesterase and produce effects related to overstimulation of the cholinergic branch of the autonomic nervous system. Barbiturates control the convulsions produced by the chlorinated hydrocarbon insecticides. Atropine blocks most of the effects of the organic phosphate insecticides. These compounds may be grouped in the following order of decreasing toxicity: TEPP, HETP, parathion, OMPA, ENP, aldrin, chlorophenothane, toxaphene, gamma benzene hexachloride, malathon and chlordane.     

What is truth – in science and beyond

Truth is threatened in our societies and one might wish that scientists should stand up for truth, but in order to do so, one needs to know what is truth and how it can be recognized. The oldest and most widely accepted concept of truth is the Correspondence Theory requesting a fit of propositions and reality. In the Coherence Theory truth is a consistent property of a whole system of propositions. In the Pragmatic Theory truth works in practical terms. Scientists have defined criteria to verify true statements by experiments and by the simplicity of theories. Aristotle proposed parsimony claiming the superiority of theories which derive from fewer hypotheses. David Hume suggested probability arguments to assess the force of evidence. Nicolai Hartmann elaborated a model based on the congruence of a priori logical arguments with a posteriori empirical observations. Karl Popper introduced the falsification of testable theories as a way to better theories. The analysis shows that scientific and medical research uses classical philosophical criteria of truth in their daily work. Humanities use different, hermeneutic criteria of truth. Finally, societies need for their coherence a dialectic approach to truth based on honest discussion of opposing views.     

Purification and Chemistry of Bacteriophage ?

From a stock of varkappa phage grown on Salmonella, a host-range mutant which attacks Escherichia coli was isolated. As in the case of Salmonella, only motile strains of E. coli are sensitive to varkappa. The phage shows an eclipse period of 35 min and a minimal latent period of 52 min. The adsorption rate constant is 3 x 10(-9) ml/min. Adsorption shows a marked dependence on temperature. Bacteriophage varkappa was purified by differential centrifugation and CsCl density gradient centrifugation. It contains deoxyribonucleic acid (DNA) which is double-stranded. The DNA has a molecular weight of 42 million and a guanine plus cytosine content of 57%. Of 68 molecules of DNA inspected, 7 were circular. The phage particle weight is about 90 million.     

Production and localization of cellulases and β-glucosidase from the thermophilic fungusThielavia terrestris

Summary The enzyme production and localization ofThielavia terrestris strains C464 and NRRL 8126 were compared to determine their optimum temperature and pH for cellulase activity. High levels of intracellular -glucosidase activity were detected in the former strain. The intracellular -glucosidase of both strains were more thermostable than the extracellular enzyme; the half life ofT.terrestris (C464) endoglucanase activity at 60°C was greater than 96 hrs.     

Alpha-tocopherol and MRI Outcomes in Multiple Sclerosis – Association and Prediction

Objective

Alpha-tocopherol is the main vitamin E compound in humans, and has important antioxidative and immunomodulatory properties. The aim of this study was to study alpha-tocopherol concentrations and their relationship to disease activity in Norwegian multiple sclerosis (MS) patients.

Methods

Prospective cohort study in 88 relapsing-remitting MS (RRMS) patients, originally included in a randomised placebo-controlled trial of omega-3 fatty acids (the OFAMS study), before and during treatment with interferon beta. The patients were followed for two years with repeated 12 magnetic resonance imaging (MRI) scans and nine serum measurements of alpha-tocopherol.

Results

During interferon beta (IFNB) treatment, each 10 µmol/L increase in alpha-tocopherol reduced the odds (CI 95%) for simultaneous new T2 lesions by 36.8 (0.5–59.8) %, p = 0.048, and for combined unique activity by 35.4 (1.6–57.7) %, p = 0.042, in a hierarchical regression model. These associations were not significant prior to IFNB treatment, and were not noticeably changed by gender, age, body mass index, HLA-DRB1*15, treatment group, compliance, or the concentrations of 25-hydroxyvitamin D, retinol, neutralising antibodies against IFNB, or the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. The corresponding odds for having new T1 gadolinium enhancing lesions two months later was reduced by 65.4 (16.5–85.7) %, p = 0.019, and for new T2 lesions by 61.0 (12.4–82.6) %, p = 0.023.

Conclusion

During treatment with IFNB, increasing serum concentrations of alpha-tocopherol were associated with reduced odds for simultaneous and subsequent MRI disease activity in RRMS patients.     

Small proteins in bacteria – Big challenges in prediction and identification

Proteins with up to 100 amino acids have been largely overlooked due to the challenges associated with predicting and identifying them using traditional methods. Recent advances in bioinformatics and machine learning, DNA sequencing, RNA and Ribo-seq technologies, and mass spectrometry (MS) have greatly facilitated the detection and characterisation of these elusive proteins in recent years. This has revealed their crucial role in various cellular processes including regulation, signalling and transport, as toxins and as folding helpers for protein complexes. Consequently, the systematic identification and characterisation of these proteins in bacteria have emerged as a prominent field of interest within the microbial research community. This review provides an overview of different strategies for predicting and identifying these proteins on a large scale, leveraging the power of these advanced technologies. Furthermore, the review offers insights into the future developments that may be expected in this field.     

Monitoring defensive responses in macroalgae – limitations and perspectives

As part of an ongoing research program aiming at monitoring molecular changes in the tissues and metabolite trafficking in the hydrosphere of algae subjected to chemical stresses, we are discussing the various analytical techniques that have been employed to characterize, and sometimes to quantity these metabolites. High-field multinuclear and solid-state nuclear magnetic resonance (NMR) spectroscopies are powerful tools for metabolite characterization from extracts and in vivo, but quantification and kinetic aspects show some limitations. Modern MS (mass spectrometry) is extremely useful for fingerprinting samples against databases and when dealing with very low concentrations of metabolites, the limitations being set by the type of chromatographic separation and mode of detection coupled with the mass spectrometer. Regarding chemical communication, optimization in terms of resolution and efficiency of hydrosphere chemical analysis can theoretically be achieved in a system which integrates (i) a multiparametric incubation chamber, (ii) a gasphase or a liquid-phase separation system and (iii) mass spectrometer(s) equipped with one or two detectors responding to the analytical and quantitative needs. This text reviews some of the techniques that have been employed in various types of plant metabolic studies, which may serve as a basis towards an integrative analytical strategy directly applicable to the metabolomics of selected marine macrophytes.     

Speciation of dimethyltin(IV) – and trimethyltin(IV) – carbocysteinate and – glutamate systems in aqueous media

Abstract

The formation of complex species in the dimethyltin(IV) and trimethyltin(IV)-carboxymethyl-L-cysteinate (carbocysteinate) systems in NaCl_aq, at different ionic strengths, and in a multicomponent Na⁺, K⁺, Ca²⁺ ,Mg²⁺, Cl^? and SO₄^2-? medium representative of the seawater major composition, is discussed. Experimental results give evidence for the formation of the following species (L = carbocysteinate): [(CH₃)₂Sn(L)]⁰, [(CH₃)₂Sn(HL)]⁺, [(CH₃)₂Sn(OH)(L)]^?, [(CH₃)₂Sn(OH)₂(L)]^2? in the DMT–CCYS system, and [(CH₃)₃Sn(HL)]⁰, [(CH₃)₃Sn(L)]^? and [(CH₃)₃Sn(OH)(L)]^2? in the TMT-CCYS system. The ionic strength dependence of formation constants was taken into account by an extended Debye Hückel type equation and by the SIT (Specific ion Interaction Theory). Measurements were carried out also on the dimethyltin(IV)-glutamate and trimethyltin(IV)-glutamate systems in NaCl_aq, owing the strict similarity of glutamate and carbocysteinate. Results obtained show the formation of complex species having the same stoichiometry as those formed in the DMT- and TMT-carbocysteinate systems, with very similar stability, confirming that carbocysteinate behaves as a dicarboxylic amino acid without involving the sulfur-bridge potential binding site in metal coordination.     

Selenium Digestibility and Bioactivity in Dogs: What the Can Can,the Kibble Can’t

There is a growing concern for the long-term health effects of selenium (Se) over- or underfeeding. The efficiency of utilization of dietary Se is subject to many factors. Our study in dogs evaluated the effect of diet type (canned versus kibble) and dietary protein concentration on Se digestibility and bioactivity. Canned and kibble diets are commonly used formats of dog food, widely ranging in protein concentration. Twenty-four Labrador retrievers were used and four canned and four kibble diets were selected with crude protein concentrations ranging from 10.1 to 27.5 g/MJ. Crude protein concentration had no influence on the digestibility of Se in either canned or kibble diets, but a lower Se digestibility was observed in canned compared to kibble diets. However, the biological activity of Se, as measured by whole blood glutathione peroxidase, was higher in dogs fed the canned diets than in dogs fed the kibble diets and decreased with increasing crude protein intake. These results indicate that selenium recommendations in dog foods need to take diet type into account.     

Tusks and tools – Experiments in carving mammoth ivory

In the past, the author replicated several Stone Age art objects, preferentially those made from mammoth tusk, using authentic tools and techniques. This contribution describes the results of his research work and the experiences he collected during the experiments, not only in relation to the material and its properties but also concerning the use of flint tools and their technical aspects. In addition, the author gives a brief overview about his subsequent considerations regarding early artisans, their skills and their social position.     

Alicyclic β-amino acids in Medicinal Chemistry

Summary. The structural element of alicyclic β-amino acids shows some remarkable biological effects: For some 5- and 6-membered β-amino acids a unique anti fungal activity has been observed, 7-membered β-amino acid derivatives have been investigated for neurological disorders. The application of 5-, 6- and 7-membered alicyclic β-amino acids in Medicinal Chemistry will be reported.     

Diet-delivered RNAi in Helicoverpa armigera – Progresses and challenges

Helicoverpa armigera (the cotton bollworm) is a significant agricultural pest endemic to Afro-Eurasia and Oceania. Gene suppression via RNA interference (RNAi) presents a potential avenue for management of the pest, which is highly resistant to traditional insecticide sprays. This article reviews current understanding on the fate of ingested double-stranded RNA in H. armigera. Existing in vivo studies on diet-delivered RNAi and their effects are summarized and followed by a discussion on the factors and hurdles affecting the efficacy of diet-delivered RNAi in H. armigera.