Presence Of Various Amino Acids Research Articles

Single Crystals of α–LiIO3 Doped with L–arginine and L–nitroarginine

One of the essential crystals for technology is the hexagonal modification of lithium iodate (α–LiIO3), which is endowed with nonlinear optical, pyroelectric, piezoelectric, acousto–optic properties. In recent years, a number of research groups studied physical and physiochemical properties of several single crystals (KDP, ADP, BTCA, ZTC) that were grown in the presence of various amino acids (L–alanine, L–glycine, L–arginine, L–lysine, etc.). In all these studies a positive effect on growth process and crystal quality is described for the amino acids being used as dopants in solutions. Based on the promising results of existing studies, in this work the effect of mixtures of the amino acids L–arginine and L–nitroarginine on α–LiIO3 single crystals is presented. Studies of IR spectrum, UV–Vis transmittance, thermal properties and nonlinear optical activity have shown that the optical quality and physicochemical properties of the crystal were improved in the presence of amino acid dopands. Our data indicates that second harmonic generation activity of the crystals of α–LiIO3 grown with L–arginine and L–nitroarginine dopants is 1.2 times higher than that of pure α–LiIO3.

New avenue for preparation of potential hydrogen storage materials based on K10 montmorillonite and Ca2Mn3O8/CaMn3O6 nanocomposites

This research outlines a novel designed nanocomposite (Ca2Mn3O8/CaMn3O6/MMT) for electrochemical hydrogen storage with highlight on the improve condition to attain higher performance. Ca2Mn3O8/CaMn3O6/MMT nanocomposites were prepared by loading different ratios of the Ca2Mn3O8/CaMn3O6 (5%, 10% and 25%) inside the montmorillonite K10. Electrochemical properties of the samples - montmorillonite K10, Ca2Mn3O8/CaMn3O6 and the respective nanocomposites - were considered by chronopotentiometry charge–discharge techniques in KOH medium. The Ca2Mn3O8/CaMn3O6 as additive were fabricated by a sol-gel route in the presence of various amino acids as both fuel and capping agent (glycine, alanine and leucine). The influence of amino acids on the morphology and purity of as-synthesized samples were studied by different analysis methods. The K10 montmorillonite (K10 MMT) functionalized with silane groups using (3-Aminopropyl) triethoxysilane (APTES) agent to link with nanoparticles. Fabricated Ca2Mn3O8/CaMn3O6/MMT nanocomposites applied as active material in the hydrogen storage system. Effect of weight percent of Ca2Mn3O8/CaMn3O6 nanoparticles in the K10 MMT matrix investigated in terms of hydrogen storage capacity. The discharge capacity for Ca2Mn3O8/CaMn3O6 nanoparticles and K10 MMT measured 552 and 140 mAhg−1 respectively. However, the discharge capacity for Ca2Mn3O8/ CaMn3O6/MMT nanocomposites with weight percent of 5, 10 and 25% nanoparticles in 2 M KOH calculated about 185, 316 and 269 mAhg−1 at current of 1 mA respectively. According to the obtained results, the Ca2Mn3O8/CaMn3O6/MMT nanocomposites with 10% nanoparticles on the MMT surface affirmed optimized capacity for hydrogen storage systems by cooperation of spillover, redox and physisorption mechanisms.

Cd(II) removal from amino acids-bearing wastewater: Critical evaluation and comparison of using magnetic carbon nanotubes vs. magnetite

In the present work, two magnetic adsorbents (magnetic carbon nanotunes “MCNT” and magnetite “Mag”) were tested for cadmium “Cd(II)” removal from water in the presence of various amino acids “AA” (aspartic acid, glutamic acid “Glu”, glycine and cysteine). MCNT was prepared by initially oxidizing carbon nanotubes (CNT) by three different methods: nitric acid method, ammonium persulphate method, Hummer's method. Magnetite was then deposited on the oxidized CNT to produce the corresponding magnetic carbon nanotube adsorbents: NA-MCNT, APS-MCNT, HUM-MCNT, respectively. Adsorption of Cd(II) on various MCNT was investigated in the presence/absence of AA where various factors were studied: pH, oxidation method of CNT, type of AA, magnetite-to-CNT ratio. It was found that the presence of AA significantly reduced the adsorption capacity of MCNT towards Cd(II) at all pHs (reduction occurred from 49.8 mg g−1 to 12.5 mg g−1). Contrary adsorption capacity of Cd(II) on bare magnetite “Mag” was noticeably enhanced in the presence of AA (for Glu, enhancement occurred from 6.9 to 22.3 mg g−1). Due to cheapness of Mag relative to CNT, it was recommended to use Mag rather than MCNT for Cd(II) removal from AA-bearing water. So that the optimum uptake method was proposed using Mag at pH 8 in the presence of Glu at concentration ratio (1:3 Cd(II): Glu). Mag was selective towards Cd(II) even in the presence of co-existing ions. The use of Mag for five cycles decreased adsorption efficiency to 80% which indicated that adsorption system was cost effective. Real water samples gave higher adsorption of Cd(II) in the presence of Glu than in distilled water. As a conclusion, it was recommended to use Mag rather than MCNT for Cd(II) removal in the presence of AA.

A novel full symmetric diarylethene-based ratiometric fluorescent sensor for lysine and the application for a logic circuit.

A novel diarylethene-based ratiometric fluorescent sensor with full symmetric structure, 1o, was designed and synthesized successfully. 1o could identify lysine (Lys) with high selectivity and sensitivity and the fluorescence emission peak was red shifted 85 nm upon addition of Lys, which could realize ratio recognition. It exhibited excellent anti-interference performance in the presence of various amino acids in CH3 CN/H2 O (7/3, v/v) solution. Moreover, the limit of detection of 1o to Lys could reach 0.019 μM based on a good linear range of 0-40 μM. In addition, the fluorescence emission intensity of 1o could be turned off/on by ultraviolet/visible light due to the special structure of diarylethene. A logic circuit was designed with three inputs. The ratiometric fluorescent sensor 1o could be as a new tool and provide a new method for detection of Lys.

In Situ Synthesis of Amino Acid Functionalized Carbon Dots with Tunable Properties and Their Biological Applications.

Emissive carbon dots (C-Dots) are known for displaying versatile properties, which have been widely utilized in many applications such as bioimaging, light-emitting devices, and photocatalysis. Further functionalization can tune their physical and chemical properties, which play the key role in many biologically and chemically relevant applications. Amino acids provide an attractive means for introducing functionality with a structural diversity. In this work, water-soluble emissive C-Dots were synthesized from pyrolysis of citric acid in the presence of various amino acids under hydrothermal conditions. We established that the diverse functionality-bearing polyamides and the polyester backbone of C-Dots are the origin of optical properties with a high quantum yield. The amino acid based C-Dots were systematically characterized using various analytical methods to confirm the core structure as well as the functionality. The results show that, depending on functionalization, the quantum yield can be varied and enhanced up to 62% and surface charge and hydrophobicity can be tuned. Most importantly, we observed a correlation between the quantum yield and properties of the side chain residue of amino acids such as hydrophobicity index and volume. Furthermore, it was found that the synthesized, diversely functionalized C-Dots exhibit no cellular toxicity and can be used for cell imaging. Due to variable surface functionality, we have also applied these C-Dots for array-based protein sensing. Overall, based on this reported method, we can easily tune the optical as well as surface properties of C-Dots, which will be suitable for many future applications.

THE METHOD OF DETECTION OF BIOMOLECULES FOR THE CREATION OF SENSORS BASED ON NANO-STRUCTURED Si.

In the work, the modification of photoluminescence spectra in the processing of porous silicon in aqueous solutions with different oxygen contents and aqueous solutions of amino acids was studied in order to further create a sensor sensitive to chemically active oxygen near the surface of porous silicon in the presence of various amino acids. he growth of the photoluminescence intensity at the processing of porous silicon in distilled water and the sensitivity of the intensity of photoluminescence to the oxygen content in water are revealed. It is proposed to use a change in the intensity of luminescence to study the properties of biomolecules, namely the determination of the amount of chemically active oxygen near the surface of porous silicon in the presence of various amino acids. Changing the sizes of nanocrystals is the main reason for increasing the intensity of photoluminescence when processing porous silicon in aqueous solutions. After applying to the surface of samples of porous silicon aqueous solutions of glycine, alanine, phenylalanine, the intensity of photoluminescence varies for all samples. Changing the sizes of nanocrystals is the main reason for increasing the intensity of photoluminescence when processing porous silicon in aqueous solutions. After applying to the surface of samples of porous silicon aqueous solutions of glycine, alanine, phenylalanine, the intensity of photoluminescence varies for all samples. Key words: photoluminescence, nanostructured porous silicon, biosensors.

PHENOTYPIC CHARACTERIZATION OF PSEUDOMONAS SYRINGAE pv. TABACI, THE CAUSAL AGENT OF TOBACCO WILDFIRE

Tobacco wildfire caused by Pseudomonas syringae is a major destructive foliar bacterial disease worldwide. Phenotypic characterization of the pathogen was investigated to provide some basic information for biology and pathology by using BIOLOG Phenotype MicroArray (PM). Using PM plates 1 to 10, 950 different growth conditions were tested. Results showed that the pathogen was able to metabolize 37.89% of tested carbon sources, 13.42% of nitrogen sources, and 10.17% of phosphorus sources, whereas it metabolized none of the tested sulfur sources and presented no biosynthetic pathways. Most informative utilization patterns for carbon sources of P. syringae were carbohydrates and amino acids, and for nitrogen were only amino acids. It showed active metabolism at 3% sodium chloride, at the combination of N-N dimethyl glycine with 6% sodium chloride, at the combination of trigonelline with 6% sodium chloride, at 4% potassium chloride, at 3% and 5% sodium sulfate, at 15% ethylene glycol, at 1% sodium lactate, at 100 mM sodium nitrate, with up to 200 mM sodium phosphate (pH 7), and with up to 50 mM ammonium sulfate (pH 8). It exhibited active metabolism in the range of pH values between 5.5 and 6. P. syringae showed poor decarboxylase activities, whereas no deaminase activity in the presence of various amino acids.

Characterization of Casein Fractions – Comparison of Commercial Casein and Casein Extracted from Cow’s Milk

Biopolymer casein was isolated from cow’s milk by acid coagulation, which was initiated by acetic acid and sodium acetate in the first, and hydrochloric acid in the second process. The casein isolated by acid coagulation, i.e. by first process, and commercial casein were separated on α-, β-, (α+κ)- and κ casein by urea fractionation. The aim of this study was to compare various properties of commercial casein fractions with casein fractions isolated from cow’s milk. The structure of casein and casein fraction samples were monitored by Fourier transform infrared spectroscopy (FTIR), and the obtained vibrational bands showed structural differences between isolated and commercial casein (presence of various amino acids), as well as their fractions. Differential scanning calorimetry (DSC) was used to determine glass transition temperature. The results showed that the glass transitions of the isolated and commercial casein were below room temperature (Tg = 2–30 °C) due to the destruction of the samples structure that provides molecules mobility and leads to a phase transition. Thermal degradation obtained by thermogravimetric analysis (TGA) of all samples occurred in multiple steps. From the results, it is evident that 5 mass % of the each sample degraded at significantly different temperatures (T95), and it can be concluded that isolated casein and its fractions showed better heat stability than commercial casein and its fraction.

Metabolic phenomics of bacterium Pantoea sp. from larval gut of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Gut bacterium Pantoea sp. is one of the predominant bacterial species in the larval gut of the diamondback moth, Plutella xylostella. The phenotypic characters of Pantoea sp. were investigated with BIOLOG phenotype MicroArray (PM) in this study. Totally 950 different metabolic phenotypes were tested using the PM plates 1–10. Results exhibited that Pantoea sp. was able to metabolize 37.37 % of the tested carbon sources, 91.32 % of nitrogen sources, 100 % of sulfur sources, and 98.31 % of phosphorus sources. Most informative utilization patterns for carbon sources of Pantoea sp. were organic acids and carbohydrates, and for nitrogen were various amino acids. The bacterium had 94 different biosynthetic pathways. It had a wide range of adaptabilities, and could still metabolize in osmolytes with up to 9 % sodium chloride, 6 % potassium chloride, 5 % sodium sulfate, 20 % ethylene glycol, 4 % sodium formate, 4 % urea, 5 % sodium lactate, 200 mmol/L sodium phosphate (pH 7.0), 100 mmol/L ammonium sulfate (pH 8.0), 100 mmol/L sodium nitrate, and 100 mmol/L sodium nitrite, respectively. It also exhibited active metabolism under pH values between 4.5 and 10. Pantoea sp. showed active decarboxylase activities while poor deaminase activities in the presence of various amino acids. The phenotypic characterization of Pantoea sp. increased our knowledge of the bacterium, in particular its interactions with insect hosts and the adaptability in gut environments, and showed us some possible approaches to controlling diamondback moth through decreasing Pantoea sp. density.

Heterocyclic aromatic amines in grilled beef: The influence of free amino acids, nitrogenous bases, nucleosides, protein and glucose on HAAs content

The aim of the study was to determine the content and profile of heterocyclic aromatic amines (HAAs) formed during the process of grilling beef under various conditions and involving different cuts of beef meat. 4,8-DiMeIQx was the most prevalent (4.50–7.55ngg−1) the next were: MeIQx (1.10–7.20ngg−1), MeIQ (1.70–5.30ngg−1), and IQ (0.38 2.00ngg−1). Changes in HAAs content, depending on the chemical composition of beef meat, were investigated; the compounds under analysis included free amino acids, glucose and protein as well as free nitrogenous bases and their nucleosides. It was demonstrated that HAAs formation strongly correlates with the presence of various amino acids in raw beef as well as that of glucose and protein (correlation coefficient 0.84–0.93). It was also demonstrated that free purine bases, pyrimidine bases and their nucleosides, which had never previously been studied in terms of their role as substrates for HAAs synthesis, correlate very strongly with HAA formation in grilled beef (correlation coefficient 0.78–0.99). The influence of thermal processing at high temperatures on the thermal decomposition of aminoimidazoazaarenes has not been corroborated by the present study.

Electrochemical investigation of the redox couple Fe(III)/Fe(II) in the presence of amino acids and neurotransmitters

The electrochemical behaviour of a Fe(III)/Fe(II) redox couple in the presence of various amino acids and neurotransmitters such as monoaminergic neurotransmitters (dopamine, adrenaline and noradrenaline) has been studied. Ammonium iron(II) sulfate served as a source of iron. Solubility required that studies being conducted at low pH values. Cyclic voltammetry experiments revealed the capability of amino acids and neurotransmitters to interact with free iron and, hence, change its electrochemical behaviour. In addition to confirm complexation reactions occurring between Fe(II) and amino acids and neurotransmitters potentiometric studies have been carried out. Calvin-Bjerrum pH-titration technique as used by Irving and Rossotti has been applied to determine stability constants at 25°C.

Investigation of amino acid-polymer aqueous biphasic systems.

Aiming at gathering further information to evaluate the recently proposed1,2 mechanism of the salt effect in aqueous polymer solutions, experimental vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE), and volumetric-compressibility measurements were carried out for several polymer-amino acid aqueous systems. The constant water activity lines (obtained through the isopiestic method at 298.15 K) of aqueous polypropylene glycol 400 (PPG400) + alanine or glycine systems, which form aqueous biphasic systems (salting-out effect), have a concave and convex slope, respectively, in the one-phase and two-phase regions. However, all the investigated polyethylene glycols (PEG400, PEG2000, PEG6000, and PEG10000) do not form aqueous biphasic systems with alanine or glycine (salting-in effect) and their constant water activity lines have a convex slope. In the second part of this work, the apparent molar volume and isentropic compressibility of transfer of alanine and glycine from water to aqueous solutions of PEG200, PEG2000, PEG10000, and PPG400 were studied at different temperatures. The third part of this work is concerned with the determination of LLE phase diagrams for several ternary polymer-amino acid aqueous systems containing polymers PPG400 and PPG725 and amino acids alanine, glycine, serine, and proline at different temperatures. On the basis of the obtained cloud point values of aqueous solutions of PPG725 in the absence and presence of various amino acids, it was found that all the investigated amino acids have a salting-out effect on PPG725 in aqueous solutions and entropy is the driving force for biphasic formation.

New Chemodosimetric Reagents as Ratiometric Probes for Cysteine and Homocysteine and Possible Detection in Living Cells and in Blood Plasma

In this work, we have rationally designed and synthesized two new reagents (L(1) and L(2)), each bearing a pendant aldehyde functionality. This aldehyde group can take part in cyclization reactions with β- or γ-amino thiols to yield the corresponding thiazolidine and thiazinane derivatives, respectively. The intramolecular charge-transfer (ICT) bands of these thiazolidine and thiazinane derivatives are distinctly different from those of the molecular probes (L(1) and L(2)). Such changes could serve as a potential platform for using L(1) and L(2) as new colorimetric/fluorogenic as well as ratiometric sensors for cysteine (Cys) and homocysteine (Hcy) under physiological conditions. Both reagents proved to be specific towards Cys and Hcy even in the presence of various amino acids, glucose, and DNA. Importantly, these two chemodosimetric reagents could be used for the quantitative detection of Cys present in blood plasma by using a pre-column HPLC technique. Such examples are not common in contemporary literature. MTT assay studies have revealed that these probes have low cytotoxicity. Confocal laser scanning micrographs of cells demonstrated that these probes could penetrate cell membranes and could be used to detect intracellular Cys/Hcy present within living cells. Thus, the results presented in this article not only demonstrate the efficiency and specificity of two ratiometric chemodosimeter molecules for the quantitative detection of Cys and Hcy, but also provide a strategy for developing reagents for analysis of these vital amino acids in biological samples.

Diferenciação in vitro de células-tronco mesenquimais da medula óssea de cães em precursores osteogênicos

O objetivo principal da nossa pesquisa foi avaliar o potencial de diferenciação osteogênica de células-tronco mesenquimais (MSC) obtidas da medula óssea do cão. As MSC foram separadas pelo método Ficoll e cultivadas sob duas condições distintas: DMEM baixa glicose ou DMEM/F12, ambos contendo L-glutamina, 20% de SFB e antibióticos. Marcadores de MSC foram testados, confirmando células CD44+ e CD34- através da citometria de fluxo. Para a diferenciação osteogênica, as células foram submetidas a quatro diferentes condições: Grupo 1, as mesmas condições utilizadas para a cultura de células primárias com os meios DMEM baixa glicose suplementado; Grupo 2, as mesmas condições do Grupo 1, mais os indutores de diferenciação dexametasona, ácido ascórbico e b-glicerolfosfato; Grupo 3, células cultivadas com meios DMEM/F12 suplementado; e Grupo 4, nas mesmas condições que no Grupo 3, mais indutores de diferenciação de dexametasona, ácido ascórbico e b-glicerolfosfato. A diferenciação celular foi confirmada através da coloração com alizarin red e da imunomarcação com o anticorpo SP7/Osterix. Nós observamos através da coloração com alizarin red que o depósito de cálcio foi mais evidente nas células cultivadas em DMEM/F12. Além disso, usando a imunomarcação com o anticorpo SP/7Osterix obtivemos positividade em 1:6 células para o Meio DMEM/F12 comparada com 1:12 para o meio DMEM-baixa glicose. Com base nos nossos resultados concluímos que o meio DMEM/F12 é mais eficiente para a indução da diferenciação de células-tronco mesenquimais caninas em promotores osteogênicos. Este efeito provavelmente ocorre em decorrência da maior quantidade de glicose neste meio, bem como da presença de diversos aminoácidos.

Oral l-serine supplementation reduces production of neurotoxic deoxysphingolipids in mice and humans with hereditary sensory autonomic neuropathy type 1

Hereditary sensory and autonomic neuropathy type 1 (HSAN1) causes sensory loss that predominantly affects the lower limbs, often preceded by hyperpathia and spontaneous shooting or lancinating pain. It is caused by several missense mutations in the genes encoding 2 of the 3 subunits of the enzyme serine palmitoyltransferase (SPT). The mutant forms of the enzyme show a shift from their canonical substrate L-serine to the alternative substrate L-alanine. This shift leads to increased formation of neurotoxic deoxysphingolipids (dSLs). Our initial analysis showed that in HEK cells transfected with SPTLC1 mutants, dSL generation was modulated in vitro in the presence of various amino acids. We therefore examined whether in vivo specific amino acid substrate supplementation influenced dSL levels and disease severity in HSAN1. In mice bearing a transgene expressing the C133W SPTLC1 mutant linked to HSAN1, a 10% L-serine–enriched diet reduced dSL levels. L-serine supplementation also improved measures of motor and sensory performance as well as measures of male fertility. In contrast, a 10% L-alanine–enriched diet increased dSL levels and led to severe peripheral neuropathy. In a pilot study with 14 HSAN1 patients, L-serine supplementation similarly reduced dSL levels. These observations support the hypothesis that an altered substrate selectivity of the mutant SPT is key to the pathophysiology of HSAN1 and raise the prospect of l-serine supplementation as a first treatment option for this disorder.

Turn-on Luminescent Probe for Cysteine/Homocysteine Based on a Ruthenium(II) Complex

A unique ruthenium(II) complex, tris(4-methyl-2,2'-bipyridyl-4'-carboxaldehyde)Ru(II) hexafluorophosphate [Ru(CHO-bpy)(3)](PF(6))(2), has been designed and synthesized as a highly sensitive and selective luminescence probe for the recognition and detection of cysteine (Cys) and homocysteine (Hcy). The almost non-luminescent probe can rapidly react with Cys and Hcy to yield the corresponding thiazolidine and thiazinane derivatives, accompanied by the remarkable luminescence enhancement and a large blue-shift of the maximum emission wavelength from 720 to 635 nm. The dose-dependent luminescence enhancement of the probe shows a good linearity in the Cys/Hcy concentration range of 15 to 180 microM with the detection limits of 1.41 microM and 1.19 microM for Cys and Hcy, respectively. Furthermore, the luminescence response of the probe is highly specific to Cys/Hcy only even in the presence of various amino acids, protein, and DNA. The results of this work not only demonstrate the efficacy and advantages of the Ru(II) complex-based luminescence probe for the sensitive and selective detection of Cys/Hcy but also provide a useful strategy for the rational design of Ru(II) complex-based luminescence probes for various biological molecules.

Isolation and characterization of a Mastigocladus species capable of growth, N(2)-fixation and N-assimilation at elevated temperature.

A Mastigocladus species was isolated from the hot spring of Jakrem (Meghalaya) India. Uptake and utilization of nitrate, nitrite, ammonium and amino acids (glutamine, asparagine, arginine, alanine) were studied in this cyanobacterium grown at different temperatures (25°C, 45°C). There was 2-3 fold increase in the heterocyst formation and nitrogenase activity in N-free medium at higher temperature (45°C). Growth and uptake and assimilation of various nitrogen sources were also 2-3 fold higher at 45°C indicating that it is a thermophile. The extent of induction and repression of nitrate uptake by NO(3) (-) and NH(4) (+), respectively, differed from that of nitrite. It appeared that Mastigocladus had two independent nitrate/nitrite transport systems. Nitrate reductase and nitrite reductase activitiy was not NO(3) (-)-inducible and ammonium or amino acids caused only partial repression. Presence of various amino acids in the media partially repressed glutamine synthetase activity. Ammonium (methylammonium) and amino acid uptake showed a biphasic pattern, was energy-dependent and the induction of uptake required de novo protein synthesis. Ammonium transport was substrate (NH(4) (+))-repressible, while the amino acid uptake was substrate inducible. When grown at 25°C, the cyanobacterium formed maximum akinetes that remained viable upto 5 years under dry conditions.

Bioinspired Synthesis of Crystalline TiO2: Effect of Amino Acids on Nanoparticles Structure and Shape

Crystalline titanium dioxide particles were obtained through the thermohydrolysis at 60 °C of an aqueous TiCl4 precursor in the presence of various amino acids. These protein building blocks were employed to modify the phase distribution, size, and shape of the formed nanoparticles. The consequences of the presence of biological species during the different steps of the inorganic condensation were characterized by a variety of techniques, including X-ray diffraction, transmission electron microscopy, and thermogravimetric analysis coupled with differential scanning calorimetry. The amino acid side chain functions were shown to be of particular importance in regard to the modification of the TiO2 structure and morphology. More specifically, aspartic acid, glutamic acid, and serine allowed the formation of pure anatase nanoparticles. The pH of the reacting solution also proved to be a relevant parameter to control the particle size and shape. Explanations based on the actual knowledge on the titania/amino a...

Biomolecule-Assisted Synthetic Route to Nanostructured Crystals: Synthesis of CdS Hierarchical Dendrites

A general biomolecule-assisted synthetic route has been developed for the synthesis of nanostructured inorganic crystals. In this work, CdS hierarchical dendrites were hydrothermally prepared through the reactions of cadmium chloride with thiourea in the presence of various amino acids and investigated in terms of change of size and shape by varying growth parameters for the sulfide crystals. X-ray diffraction demonstrated that the as-fabricated CdS dendrites were in wurtzite (hexagonal) phase, and electronic diffraction further determined that the CdS dendrites were in hexagonal form with single-crystal nature. The experiments revealed that both amino acids and thiourea play an important role in the formation of the hierarchical crystals. Meanwhile, a possible growth mechanism is proposed, based on the investigations.

Source identification of Indian opium based on chromatographic fingerprinting of amino acids

Total and free pool of amino acids was determined in Indian opium samples using liquid chromatography (LC) with post-column o-pthalaldehyde derivatization followed by its fluorimetric detection. The limit of detection (LOD) was found to be in the range of 2–10 pmol with a signal to noise ratio of 3:1 and limit of quantitation (LOQ) was found to be in the range of 7–31 pmol with a signal to noise ratio of 10:1. The recovery of amino acids was found to be in the range of 86–103%. A total of 124 Indian opium samples were collected from the states of Madhya Pradesh (MP), Uttar Pradesh (UP) and Rajasthan (Raj), covering 14 licit opium growing divisions of India were chromatographically fingerprinted for the presence of various amino acids. The amino acids identified in sample hydrosylate included D, T, S, E, G, A, V, I, L, Y, F, H, K and R, while the analysis of free pool of amino acids (80% aqueous ethanol extract) indicated the presence of D, T, S, E, A, V, I, L, Y, H, K respectively. Multiple discriminant analysis was applied to the quantitative total amino acid data to determine an optimal classifier in order to evaluate the source of Indian opium. The foremost amino acid variables that accounted for the true discrimination were identified as D, E, G, A, F and K in evaluating the geographical origin of Indian opium and the predictive value based on the discriminant analysis was found to be 90% in relation to the source of opium samples. Chemometrics performed with amino acid analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz. groups I, II and III. The methodology developed may find wide application in forensic analysis.