Search

The pupae of Indian paper wasp, Ropalidia marginata, produce silk that covers the opening of each cells in their hives, which probably helps in thermoregulation and providing mechanical stability. In this study an attempt has been made to investigate the amino acid composition and protein structure of Indian wasp silk using bioinformatics and experimental tools. The amino acid analysis of the regenerated solubilized wasp silk revealed high alanine and serine content that increases the propensity of α-helical and random coil and/or β-sheet structure respectively. The Matrix Assisted Laser Desorption/Ionization-Time Of Flight/Time Of Flight based protein fingerprinting analysis of the regenerated solubilized wasp silk revealed its short-range sequences. The protein modeling studies indicated the presence of predominant coiled coil α-helical and random coil structure in the protein isolated from wasp hive caps, similar to previous reports from the Vespoidea family. Fourier transform infrared spectroscopic analysis and X-ray diffraction analysis of the native paper wasp cap revealed the presence of mix of coiled coil α-helix and β-sheet structure in outer regions; whereas inner region contains tannin/intermolecularly bonded hydroxyl groups of polyphenols. The present study is first report to generate valuable insights about the chemical composition and secondary structure prediction of Indian paper wasp silk and highlight on nature's novel modus operandi to engineer unique functional fibrous matrix. Image 1 • First report on silk produced by pupae of Indian paper wasp. • High alanine and serine corresponding to coiled coil α-helix and β-sheets. • Tannin and Transglutaminase induced crosslinking makes wasp silk insoluble in chaotropic agent. [ABSTRACT FROM AUTHOR]

Urine amino acid analysis has proven valuable for an array of clinical or nutritional studies. However, transportation of liquid urine sample shows certain disadvantages, such as possible leakage, need for cold chain and thus higher costs for their transport. Utilization of dried urine spots (DUS) can offer an interesting alternative. In the present study, a method was developed for the determination of 14 amino acids in DUS including the testing of in-house collection device and drying of the sample before analysis. Normal filter paper was tested as the means for sample collection. Absorption and extraction experiments were performed on 3 different types of filter paper, with 3 different extraction solvents and two different solvent volumes. The solvents used were mixtures of common analytical solvents (methanol, water, acetonitrile) using total volumes of 1 mL and 1.5 mL. Finally, 1 mL of acetonitrile: methanol: water 40:40:20 (v/v/v) was chosen as the optimal system. Analysis was performed on a UHPLC-MS system, using stable isotope labeled internal standards. Method validation included the study of limits of detection (LOD) and quantification (LOQ), linearity ranges, precision, matrix effect, extraction recovery, precision, and stability for each analyte. The obtained results were satisfactory, thus enabling application of the proposed method as an alternative to the analysis of liquid urine. Further utilization of DUS can offer advantages by enabling patient centric sampling even in long distances far from the analytical laboratories. [Display omitted] • Amino acids can accurately determined in Dried Urine Spots (DUS). • DUS were generated by samples obtained from healthy volunteers. • Similar concentrations obtained in liquid urine and DUS from 10 healthy individuals. • Application suitable for wellness and/or nutritional studies. [ABSTRACT FROM AUTHOR]

A recent paper by Bownes et al. (2017, Radiocarbon 59(5): 1275–1294) used the Bayesian modelling software package FRUITS (Fernandes et al. 2014, PLoS ONE 9(2): e87436) to argue that Neolithic individuals from Carding Mill Bay on the west coast of Scotland obtained up to ca. 21% dietary protein from marine sources. This is in contrast to previous interpretations of the same isotopic (δ 13C and δ 15N) data, which concluded that these individuals showed little if any use of marine resources (Schulting and Richards 2002, European Journal of Archaeology 5(2): 147–189). Resolving this discrepancy is important for our understanding of the nature of the Mesolithic–Neolithic transition not only on the west coast of Scotland, but along all of Atlantic Europe, since similar isotopic results to those obtained at Carding Mill Bay are widespread throughout the Neolithic and indeed later periods. We suggest that greater caution needs to be excercised in the interpretation of the output of Bayesian palaeodietary modelling, which can be very useful heuristically, but should not always be taken at face value. Given the large number of parameters employed in such models (diet isotopic values and nutrient concentrations, trophic level and tissue fractionations, etc.) and the uncertainty involved in almost all of them, a wide range of outcomes are possible, as we demonstrate in this paper. We reaffirm the overwhelmingly terrestrial nature of diet at Carding Mill Bay both through FRUITS modelling and through the new application of compound-specific δ 13C analysis of single amino acids of humans and fauna from the site. [ABSTRACT FROM AUTHOR]

Most recommended methods for visualising fingermarks on paper rely on chemical developers that target and react with amino acids. Traditionally, these developers are sprayed onto paper substrates in solutions of per- and polyfluoroalkyl substances (PFAS), but now those same PFAS chemicals are undergoing phaseout or phasedown, which threatens to undermine forensic capabilities. This situation provides an opportunity to pivot towards greener approaches to fingermark visualisation. The ideal methodology would be a water-based treatment, as these provide superior safety for practitioners, combined with environmental sustainability. A major hurdle to implementing a water-based fingermark developer targeting amino acids is that water, as a universal solvent, can dissolve the eccrine components in fingermarks, as well as any optical or luminescent dyes that are created, causing the ridge detail to run or dissolve. This work circumvents this problem by delivering the amino acid developer alloxan in a hydrogel, which enables sharp fingermark ridge details to be observed despite it being a water-based treatment. Alloxan dissolved in a viscous hydrogel is shown here to react with the amino acids in fingerprint residues to form the coloured dye murexide, supported by optimisation and characterisation studies. • New fingermark development methods are needed as PFAS chemicals are phased-out. • Water-based methods are ideal from a cost, safety, and environmental perspective. • A water-based alloxan treatment was found to develop charged fingermarks on paper. • Xanthan gum creates an alloxan hydrogel that inhibits blurring of ridge details. [ABSTRACT FROM AUTHOR]

The influence of disinfection methods on paper-based archival and library materials has been well documented and, thus, these methods are commonly used in paper conservation. However, little is known about the effect of these methods on the emulsion layer of photographic prints, which is often formed by photographic gelatin. In this paper, we examine the stability of photographic gelatin after disinfection by three methods: γ-radiation, ethylene oxide and butanol vapors. The degree of gelatin degradation and its possible mechanism were determined by monitoring its molar weight (by measuring its intrinsic viscosity), primary structure (by amino acid analysis), and secondary structure (by FTIR spectroscopy and XRD). The smallest risk to the material was posed by butanol vapors, which suggests that this is a promising disinfection method for photographic prints based on gelatin. [ABSTRACT FROM AUTHOR]

This study is the second part of a larger body of research dedicated to the production of synthetic secretions and the use of an inkjet printer to deposit realistic artificial fingermarks. An artificial emulsion combining eccrine and sebaceous compounds, which was described and tested in the first part of this research, was used as it showed a promising compatibility with common detection techniques. An inkjet printer was modified to print the emulsion on two different substrates: paper (porous) and acetate (non-porous). After optimisation of the printing parameters, multiple fingermarks were printed and processed with a range of standalone detection techniques: 1,2-indanedione-zinc, ninhydrin, Oil Red O, and physical developer on paper, and cyanoacrylate fuming, rhodamine 6G, gold/zinc vacuum metal deposition, and silver black powder on acetate. The detection techniques were also applied in sequence, which is considered one of the biggest advantages of the emulsion over simpler amino acid mixtures that are usable with amino acid reagents only. Natural fingermarks deposited by a single donor were processed with the same techniques for comparison. The effect of water immersion was also investigated, where fingermarks printed on paper were immersed in water for 15 min, before being processed with 1,2-indanedione-zinc and Oil Red O. The results showed that realistic-looking fingermarks could be printed on paper and that printing on acetate was also possible albeit of lower quality due to the nature of the substrate. The artificial fingermarks were successfully enhanced by all the detection techniques tested, at the notable exception of physical developer. The results obtained were very similar to what is generally observed with real fingermarks, and it was observed that the impact of water immersion on the artificial fingermarks was comparable as well. These findings open new perspectives for the development of multi-target quality control test strips or for the standardisation of proficiency testing and interlaboratory collaborative exercises where ground truth is crucial to guarantee comparable results and objective assessment. • Fingermark secretions were mimicked by emulsifying eccrine and sebaceous compounds. • Inkjet printer was used to print the emulsion on paper and plastic substrates. • Printed fingermarks were processed with a large selection of detection techniques. • Results obtained are comparable to real marks processed by the same techniques. • Emulsion still needs optimizations to be compatible with physical developer. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicine and ethnic medicine together play an important value in the modern medicine system that is different from that of chemical drugs. Chinese medicine and ethnic medicine with hemostatic effect have unique advantages and development potential in the prevention and treatment of clinical hemorrhagic diseases, reflecting multi-component, multi-target and multi-pathway effects. In this paper, the active ingredients related to the hemostatic effect of traditional Chinese medicine and ethnic medicine are taken as the starting point, and the traditional Chinese medicine and ethnic medicine with traditional hemostatic purposes are reviewed, and the existing research progress on the active ingredients and their mechanism of action of these drugs is systematically expounded, aiming to provide theoretical reference for the development of traditional hemostatic drugs, the discovery of hemostatic active ingredients and the research of new hemostatic methods. Hemostatic chinese medicine and ethnic medicine were collected and summarized from the classic books of Materia Medica, public literature database and doctoral or master's thesis repositories. At the same time, we discussed the classification of various types of hemostatic active ingredients of traditional Chinese medicine and ethnic medicine according to the different mechanisms of hemostasis. A total of 436 traditional Chinese medicine and ethnic medicine with hemostatic effects have been collected, and their hemostatic active ingredients include alkaloids, quinones, flavonoids, phenylpropanoids, organic acids, amino acids, terpenoids, steroids, phenols, tannins, esters, polysaccharides and herbal extracts, etc. These active ingredients accelerate the formation of hemostasis by improving endogenous and exogenous hemostatic pathways mainly through enhancing vascular wall contraction, increasing platelet aggregation, promoting coagulation system activation and inhibiting fibrinolysis. This article reviews the previous data on various aspects of the hemostatic effect of traditional Chinese medicine and ethnomedicine. Many traditional hemostatic drugs have been discovered and many active ingredients and mechanisms have been reported. However, although there are a large number of drugs with traditional hemostatic effects, there are still few developed and applied. At the same time, the hemostatic components of many drugs still remain in the study of the activity of their total extracts, and the potential link between some drug components achieving hemostatic effects through different mechanisms remains to be elucidated. [Display omitted] • A total of 436 traditional Chinese medicine and ethnic medicine with hemostatic effects have been collected. • The hemostatic active ingredients include alkaloids, quinones, flavonoids, phenylpropanol and other chemical components. • These active ingredients accelerate the formation of hemostasis mainly through four different pathways. • In this paper, many data of traditional drugs for hemostasis and provides a reference for the development of new drugs and methods for hemostasis. [ABSTRACT FROM AUTHOR]

Amino acid misincorporation during protein synthesis occurs naturally at a low level. Protein sequence errors, depending on the level and the nature of the misincorporation, can have various consequences. When site-directed mutagenesis is used as a tool for understanding the role of a side chain in enzyme catalysis, misincorporation in a variant with intrinsically low activity may lead to misinterpretations concerning the enzyme mechanism. We report here one more example of such a problem, dealing with flavocytochrome b 2 (Fcb2), a lactate dehydrogenase, member of a family of FMN-dependent L -2-hydroxy acid oxidizing enzymes. Two papers have described the properties of the Fcb2 catalytic base H373Q variant, each one using a different expression system with the same base change for the mutation. The two papers found similar apparent kinetic parameters. But the first one demonstrated the existence of a low level of histidine misincorporation, which led to an important correction of the variant residual activity (Gaume et al. (1995) Biochimie, 77, 621). The second paper did not investigate the possibility of a misincorporation (Tsai et al. (2007) Biochemistry, 46, 7844). The two papers had different mechanistic conclusions. We show here that in this case the misincorporation does not depend on the expression system. We bring the proof that Tsai et al. (2007) were led to an erroneous mechanistic conclusion for having missed the phenomenon as well as for having misinterpreted the crystal structure of the variant. This work is another illustration of the caution one should exercise when characterizing enzyme variants with low activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Printed fingermarks are relevant in the context of education and proficiency testing. • Dilution series of artificial sweat encompass the variability observed with 30 donors. • Luminescence intensity levels comparable to natural fingermarks can be produced. • Detection exercises of varying difficulty levels can easily be produced. • Artificial and natural secretions should be considered as complementary. The study presented in this paper aims at assessing how printed fingermarks can be used to generate realistic latent marks bearing varying quantities of materials to be detected. Considering dilution series of artificial sweat (eccrine secretion) and 1,2-indanedione/zinc as amino acid reagent, we assessed how printed marks behave in comparison to natural fingermarks provided by a set of 30 donors. The results were assessed in terms of relative intensity (contrast, luminescence) and expert grading (ridge details, overall quality). With regards to the set of 30 donors, this study brought a quantitative look to the influence of intra- and inter-variability on the relative intensity values observed when processing natural fingermarks. This provided new data to further understand the concept of "donorship". With regards to the use of printed marks, it has been illustrated how dilution series of a concentrated solution allows covering a range of cases: unnatural marks (intensity values well above those obtained with donors), rich marks (corresponding to fingermarks left by good donors), and faint marks (associated with the kind of results observed with poor donors). Such a range of detection performance offers the possibility to generate fine-tuned detection exercises of varying difficulty levels. Printed items made of artificial sweat could hence constitute a valuable alternative to natural secretions in the context of education and proficiency testing. [ABSTRACT FROM AUTHOR]

Specific food proteins and peptides as well as amino acids released by enzymatic hydrolysis have demonstrated several biological activities, therefore they represent an interesting perspective in agrifood, biopharmaceutical and nutraceutical industries. However, these biomolecules are present at a significantly lower concentration in a complex mixture of different sizes, conformations and net charges. Separation or fractionation of such active molecules from the complex matrices is therefore vital in order to concentrate them in more purified form. In this context, conventional pressure-driven membrane processes like UF, NF and RO are widely used as a first choice for the separation and purification of proteins, peptides and amino acids. On the other side, innovative electromembrane processes such as EMF and EDFM are recently gaining much attentions and are regarded as favorable alternatives to the conventional methods. In addition, these methods could be potentially used for the efficient separation of charged compounds like proteins, peptides and amino acids. However, as observed for filtration membranes used in pressure-driven membrane filtration techniques (MF, UF, NF and RO), ion-exchange membranes stacked in an electrodialytic cell are also subject to fouling by protein, peptide and amino-acid. Indeed, fouling of ion-exchange membranes is a real challenge as these membranes are more easily affected and altered by aggressive chemical cleaning as compared to filtration membrane. Therefore, characterization of membrane fouling is essential to understand the mechanism of fouling to control this phenomenon. Consequently, this paper will review the conventional as well as more recent technologies used for the characterization of ion-exchange and filtration membranes fouling by proteins, peptides and amino acids. In addition, conventional methods of fouling characterization have been mainly developed for filtration membranes and information about the techniques that can be used in combination with ion-exchange membranes are still lacking. Accordingly, this work will create a bridge between the conventional and current characterization methods in relation to filtration as well as ion-exchange membranes. In addition, the pros and cons of each technique are discussed with some important points to be noted to avoid their misuse. Moreover, this paper will bring a clear insight about how the methods of fouling characterization have been evolving from qualitative to quantitative analyses. Till date, more than one method are used depending on nature of fouling, foulants and membrane used although, in-situ and non-destructive characterization methods are preferred. [ABSTRACT FROM AUTHOR]

Abstract In this work, we proposed a naked-eye colorimetric strategy for simultaneous detection of cysteine and lysine based on 3,3′,5,5′-tetramethylbenzidine (TMB) system in a neutral condition (pH 7.0). Based of the fact that Ag+ could oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to oxidized TMB (oxTMB) and induce a blue color solution corresponding to an absorption peak centered at 652 nm, thus the adding of cysteine or lysine to formation of different product results in the blue color fading to colorless quickly or change to scarlet, respectively. With this strategy, the limit of detection in experimental measurement for cysteine and lysine is 2.46 μM and 3.87 μM, respectively. And the selectivity can also be guaranteed among the other amino acid. The cost is quite low since the use of TMB and Ag+. More importantly, the colorimetric detection operation is very simple without any further modification process and the reaction under physiological conditions is more meaningful for detection of amino acid. Graphical abstract Image 1 Highlights • A sensitive nanomaterials-free colorimetric sensor was explored by using a facile strategy. • TMB colorimetric system for simultaneously detecting cysteine and lysine can be achieved in a mild aqueous solution. • TMB colorimetric system was successfully converted into INHIBIT/NOR logic gate and paper-based analytical devices. [ABSTRACT FROM AUTHOR]

Abstract The present paper reported a biomimetic synthesis of mesoporous silicas (BMSs) at room temperature by using synthesized polymers (C 16 - l -His, C 16 - l -Pro and C 16 - l -Trp) which derived from amino acid with ring structures as template under basic condition via co-structural-directing-agent method. The formation mechanism of BMSs and effect of initial synthesis conditions (such as surfactant structure, pH and co-solvents) on morphology and structure of BMSs were systematically studied. Synthesized BMSs were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption/desorption isotherms. The results showed that the surfactant structure was the dominant factor to direct the final mesostructure of BMSs, since the structure of surfactant affected the structure and size of clusters. Meanwhile the generation of BMSs required very rigorous alkaline condition which controlled the ionization degree of the surfactant and thus contributing to adequate stacking energy. Higher pH resulted in construction of channels with higher curvature. The presence of ethanol was found to facilitate the formation of BMSs with larger particle size. In application, aspirin can be loaded into BMSs with high efficiency, and the drug crystalline state of aspirin transformed from crystalline state to amorphous state during this process, which undoubtedly lead to the improvement of drug dissolution from 72.8% to 100% within 90 min. It is convincible that the biomimetic method presented here provided novel insight on precisely control of mesoporous silica and undoubtedly promoted the application of mesoporous silica materials. Graphical abstract Unlabelled Image Highlights • Heterocyclic amino acid derivatives templated mesoporous silicas were synthesized using biomimetic method. • Curved channels were obtained due to dynamic self-assembly of C 16 -L-aminoacid. • Surfactant structure, pH and co-solvents influenced the final morphology and structure of mesoporous silicas. • Biomimetic synthesized mesoporous silicas possessed excellent drug loading capacity and significantly improved the drug release rate in vitro. [ABSTRACT FROM AUTHOR]

Highlights • Constitutive amino acids of various defense proteins are lost in the gut. • Stress and local or systemic inflammation divert amino acids from use for growth. • Efficient and environmental-friendly diets require better tuning of amino acid provision for different sanitary conditions. Abstract On commercial farms, young growing pigs are frequently affected by health problems from multifactorial origins (e.g. environmental changes, biosecurity, management, and feed) that result in inflammation and activation of body defenses. Inflammation states alter animal metabolism in such a way that nutrients (particularly amino acids) are diverted from the use for growth towards the production of defense-related proteins and low-molecular-weight compounds (e.g., nitric oxide, H 2 S, and glutathione) for supporting the activity of rapidly dividing cells such as immune cells and enterocytes. Furthermore, amino acids may act specifically as signaling molecules to regulate metabolic pathways during inflammation. Thus, new knowledge on the specific role and metabolism of each amino acid is needed to refine nutritional recommendations for pigs of different phenotypes and genotypes, with the objective of maintaining animal health and performance under sub-optimal rearing conditions. This paper aims at summarizing recent advances in research on the functional roles of amino acids related to swine health. Specifically, the review highlights current knowledge on the impact of inflammation on the intake and metabolism of amino acids; their relevance for the physical gut mucosal barrier and antioxidant defense, as well as their roles in the syntheses of defense molecules and in the regulation of immune response. Practical implications for feeding strategies adapted to various health conditions of growing pigs are also discussed along with our general perspectives on related research. [ABSTRACT FROM AUTHOR]

This paper contains details of work carried out to identify the most effective processing conditions for the optimized 1,2-indandione/zn formulation developed for use under UK conditions. Using direct measurements of fluorescence taken from test spots of amino acids and eccrine sweat during oven processing, complemented with experiments on real fingermarks, it was established that processing temperatures above 120°C in the oven were detrimental to the fluorescence of the developed mark. Alternative methods of development to oven processing were found to be effective, but less controllable. High levels of humidification were also found to be detrimental to the fluorescence of 1,2-indandione developed marks, and oven processing at 100°C and 0% relative humidity is therefore recommended for further studies. It has also been shown that 1,2-indandione can develop fingermarks at temperatures as low as 20°C, making it a candidate for use at crime scenes. [ABSTRACT FROM AUTHOR]

The interaction of aluminum ion Al(III) with polypeptides is a subject of paramount importance, since it is a central feature to understand its deleterious effects in biological systems. Various drastic effects have been attributed to aluminum in its interaction with polypeptides and proteins. These interactions are thought to be established mainly through the binding of aluminum to phosphorylated and non-phosphorylated amino acid sidechains. However, a new structural paradigm has recently been proposed, in which aluminum interacts directly with the backbone of the proteins, provoking drastic changes in their secondary structure and leading ultimately to their denaturation. In the present paper, we use computational methods to discuss the possibility of aluminum to interact with the backbone of peptides and compare it with the known ability of aluminum to interact with amino acid sidechains. To do so, we compare the thermodynamics of formation of prototype aluminum-backbone structures with prototype aluminum-sidechain structures, and compare these results with previous data generated in our group in which aluminum interacts with various types of polypeptides and known aluminum biochelators. Our results clearly points to a preference of aluminum towards amino acid sidechains, rather than towards the peptide backbone. Thus, structures in which aluminum is interacting with the carbonyl group are only slightly exothermic, and they become even less favorable if the interaction implies additionally the peptide nitrogen. However, structures in which aluminum is interacting with negatively-charged sidechains like aspartic acid, or phosphorylated serines are highly favored thermodynamically. [ABSTRACT FROM AUTHOR]

The amino acid composition of collagen is a characteristic feature of this protein. Collagen, irrespective of its origin, contains 19 amino acids, including hydroxyproline which does not occur in other proteins. Its atypical amino acid composition is characterized by high content of proline and glycine, as well as the absence of cysteine. This paper shows the comparison of qualitative composition of amino acids of fish skin (FS) collagen, bovine Achilles tendon (BAT) collagen, and bone collagen. Results demonstrate that FS collagen as well as BAT collagen contains no cysteine and significantly different amount of hydroxyproline. In BAT collagen hydroxyproline content is 30% higher than hydroxyproline content of FS collagen. In bone collagen the amount of hydroxyproline is two times more than in FS collagen. Furthermore, it is shown that sensitivity to radiation of individual amino acids varies and depends on the absorbed dose of ionizing radiation. The changes observed in the amino acid composition become very intense for the doses of 500 kGy and 1000 kGy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heat induces crosslinking of amino acids in gelatin and genipin in gardenia blue. • High temperature improves thermal stability and stable structure of blue system. • Blue system has the enhanced chemical stability mainly due to hyperchromic effect. • UV irradiation stability is raised due to compact matrix and gelatin protection. • Blue system has potential application in food 2D writing/printing and 3D printing. Gardenia blue could be effectively stabilized by gelatin and could be further enhanced by high-temperature based covalent-crosslinking reaction. The crosslinking reaction between amino acids and genipin promotes the generation of new gardenia blue molecules, facilitates the stable network structure, and improves the thermal stability of gelatin-gardenia blue systems (T 1 increased to 90 °C and T 2 increased from 310 °C to 315 °C), which is confirmed by UV absorbance, amino acid analysis, TGA, FTIR, XRD, SEM and particle size (774 nm). The treated samples also possess high resistance against acid and alkali chemicals (A/A0 ≈ 1) because of hyperchromic effect, high resistance against UV irradiation (ΔE < 5) due to the compact nanosized matrix, as well as great shear-thinning behavior (n < 1) and thixotropy (96.83 %). Its applications in 2D writing/printing, food functionalization and 3D printing on paper and various food, illustrate high-definition patterns and satisfying colors. Overall, the crosslinked gelatin-gardenia blue based system has potential application in food under high-temperature, acidic, basic or salty conditions, with wide consumption groups and high food industry values. [ABSTRACT FROM AUTHOR]

The corrosion inhibition performance of three choline amino acid ionic liquids ([Ch][AA]ILs) for mild steel in 1 M HCl solution was evaluated by electrochemical analysis, gravimetric measurement, and surface morphological characterization in the temperature range of 298–328 K in this paper. The results of the polarization experiments show that [Ch][AA]ILs affect the cathode and anode reaction processes, proving that [Ch][AA]ILs are mixed corrosion inhibitors. Choline phenylalanine ionic liquids ([Ch][Phe]) exhibit the highest corrosion prevention efficiency among the three chosen corrosion inhibitors, as proven by SEM/EDS scanning, XPS analysis, and molecular dynamics simulation. The values of standard free energy of adsorption Δ G ads range between − 20 kJ·mol-1 and − 40 kJ·mol-1, showing that inhibitor molecule adsorption on the metal surface involves both physical and chemical adsorption. According to the results of XPS research and quantum chemical calculations, the adsorption of corrosion inhibitor molecules on the metal surface is strongly related to the anions. The corrosion inhibitor molecules form a thick monolayer adsorption layer on the metal surface, preventing metal-corrosive media interaction. The molecular dynamics simulation findings reveal that the corrosion inhibitor molecules replace the solvent water or any other ions pre-adsorbed on the metal surface during the adsorption process, protecting the metal from corrosion. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, we report about the application of a sensitive fluorescent derivatization reagent Coumarin151- N -Hydroxysuccinimidyl Carbamate (Cou151DSC) for amino compounds using high-performance liquid chromatography (HPLC) compatible with ultraviolet (UV), fluorescence detector (FLD) and electrospray ionization - tandem mass spectrometry (ESI-MS/MS)―positive mode. We optimized derivatization procedure and validated an analytical method to determine 24 amino acids in Kvass drink using Norvaline as an internal standard. Compared to 6-Aminoquinolyl- N -Hydroxysuccinimidyl Carbamate (6-AQC), the derivatization with Cou151 DSC is faster and milder, for 5 min at 40°C instead of 15 min at 55°C. The limit of quantitation (LOQ, pmol on column) for 21 amino acids in this work is lower 1.1–30.0 times than values obtained with 6-AQC. The derivatives have excitation wavelength at 355 nm and emission wavelength at 486 nm. Their MS/MS fragmentation behaviors were examined together with 23 other amino compounds. We found three possibilities to lose a neutral group which can be Coumarin 151 isocyanate Cou151NCO (255 Da), amine Coumarin 151 (229 Da) or urea Cou151CONH 2 (272 Da). The accuracy of the proposed method was within 83–107% with good relative standard deviations (RSDs) of equal or less than 6%. The recoveries were from 82 to 120% in four spiked concentrations, repeatability was between 0 and 14%. The intra- and inter-day precision are less than 13% and 18%, respectively. [Display omitted] • Coumarin151- N -Hydroxysuccinimidyl Carbamate fluorogenic MS-based derivatization. • The derivatization can be completed in mild conditions 40 °C for 5 min. • MS/MS fragmentations of derivatized 24 amino acids and 23 amino compounds were investigated. • Coumarin 151 derivatives can be used in constant neutral loss scanning mode. [ABSTRACT FROM AUTHOR]

It is widely accepted that some of the free d -amino acids play important biological role. d -Aspartate and d -serine formed in the central nervous system of higher vertebrates have neurotransmitter/neuromodulator function. Together with d -alanine they are distributed in various tissues and biological fluids. Studying their physiological and pathological significance requires their sensitive and accurate determination in biological samples. The various separation and detection methods used for their analysis are overviewed in the present paper. Our focus is mainly the quantitative performance and the analysis of real biospecimens. [ABSTRACT FROM AUTHOR]

• Improved methods for the reliable and fast analysis of amino acids in food and feed. • Dramatic reduction of analysis time by microwave hydrolysis and UHPLC-MS/MS. • Comparable results to laboratories using ISO, AOAC and regulation (EC) 152/2009 methods. • Determination of hydroxyproline, hydroxylysine, taurine, and ornithine also possible. • High specificity and selectivity due to UHPLC-MS/MS with AQC derivatization. The determination of amino acids in food and feed by chromatography has a long history and is described in several official methods, including standards from ISO, AOAC, and the European Commission (EC) regulation 152/2009. The procedure usually consists of labor- and time-consuming preparation techniques and ion-exchange chromatography with challenging chromatographic conditions. Consequently, several approaches have been published to overcome these drawbacks but the knowledge about their suitability for complex matrices such as food and feed is limited. In this paper, we describe the development of two new methods to determine amino acids in food and feed. These methods involve microwave hydrolysis and reversed-phase UHPLC-MS/MS with pre-column derivatization using 6-aminoquinolyl- N -hydroxysuccinimidyl carbamate (AQC). Both methods provide streamlined sample preparations and a dramatic reduction in analysis time while offering a high degree of specificity and selectivity. Selectivity also enabled the simultaneous determination of the more uncommon substances hydroxyproline, hydroxylysine, taurine, ornithine, and γ-amino butyric acid (GABA) along with amino acids typically present in food and feed. The results were all satisfactory with regards to sensitivity, accuracy, precision, and comparability with laboratories that use other methods, for example from ISO, AOAC, or regulation (EC) 152/2009. We therefore concluded that both methods provide a reliable and modern approach to overcome many of the drawbacks that occur with the conventional standard methods. [ABSTRACT FROM AUTHOR]

In this paper, a novel dummy template molecularly imprinted polymer (DMIP) based on a vinyl-SiO 2 microspheres surface for the simultaneous selective recognition and enrichment of 18 amino acids was prepared via a surface molecular imprinting technique using theanine as a dummy template. Compared to the imprinted polymers prepared using traditional polymerization techniques, the obtained DMIPs exhibited a regular spherical shape and were relatively monodisperse. The maximal sorption capacity ( Q max ) of the resulting DMIPs for the 18 amino acids was up to 1444.3 mg g −1 . A kinetic binding study showed that the sorption capacity reached 85.40% of Q max in 25 min and sorption equilibrium at 30 min. The imprint factors of the sorbents ranged from 2.86 to 6.9 for the 18 amino acids, which indicated that the DMIP sorbents have high selectivity. An HPLC-UV method for the simultaneous determination of 18 amino acids in tobacco and tobacco smoke was developed using the DMIPs as sorbents for solid phase extraction (SPE) in the sample pretreatment procedure. Under the optimum experimental conditions, the materials had enrichment factors of up to 200 for the amino acids, and the recoveries of the 18 amino acids in tobacco smoke were in the range from 79% to 104% with relative standard deviations of less than 7.4%. It indicated that the obtained DMIP sorbents could specifically recognize the amino acids from complicated samples. [ABSTRACT FROM AUTHOR]

In this paper we report the synthetic procedures providing the C-substitution of the cobalt bis(dicarbollide) sandwich anion [(1,2-C 2 B 9 H 11 )-3,3′-Co] − with primary, secondary and tertiary alkylamine groups of different length of the aliphatic spacer attached to the carbon C(1) or C(1) and C(1′) cage positions. Reaction pathways leading to these compounds proceed via synthesis of mono [(1-X-O-(CH 2 ) n -1,2-C 2 B 9 H 10 ) (1′,2′-C 2 B 9 H 11 )-3,3′-Co]Me 4 N (where n = 1–3 and X = –SO 2 CH 3 or –SO 2 (-C 6 H 4 -4-CH 3 ) esters ( 2a–f ) and diesters [(1,1′-X-O-(CH 2 ) n -1,2-C 2 B 9 H 10 ) 2 -3,3′-Co]Me 4 N ( 3a-c ) (n = 1 and 2). These compounds are readily accessible in good to excellent yields by reactions of trimethylammonium salts of alkylhydroxy derivatives ( 1a–e ) of the parent ion with methylsulfonyl or p -toluenesulfonyl chloride. The esterifications proceeded with lower conversions only for methylene hydroxy derivatives. The series of primary amines of general formulation [(1- 1 R 2 RN-(CH 2 ) n -1,2-C 2 B 9 H 10 ) (1′,2′-C 2 B 9 H 11 )-3,3′-Co] − (where n = 1–3 and 1 R = 2 R = H) ( 4a–c ), along with the diamine [(1,1′–NH 2 –C 2 H 5 ) 2 -1,2-C 2 B 9 H 10 ) 2 -3,3′-Co] − ( 5 ), and compounds comprising secondary and tertiary amino functions ( 1 R = n Bu, 2 R = H, 1 R = Bn, 2 R = H and 1 R = 2 R = Et) ( 6a–h ) were prepared in generally good yields by reactions of the esters with ammonia and primary or secondary amines. However, the reactions of the bis(methylene methylsulfonyl) diester resulted in almost quantitative in situ dialkylation of the amine group leading to the formation of a triatomic bridge between two carbon atoms of the cage [(1,1′-μ-(-CH 2 NRCH 2 -) (1,2-C 2 B 9 H 10 ) 2 -3,3′-Co] − (R = H or Bu) ( 7a , b ). We believe this observation contributes further to rich evidence on the preference of bridge substitutions at the cobalt bis(dicarbollide) cage. [ABSTRACT FROM AUTHOR]

This paper reports the enantioseparation ability of a pyridino-18-crown-6 ether-based chiral stationary phase [( S,S )-CSP- 1 ]. The enantiomeric discrimination of chiral stationary phase ( S,S )-CSP- 1 was evaluated by HPLC using the mixtures of enantiomers of various protonated primary aralkylamines [1-phenylethylamine hydrogen perchlorate (PEA), 2,3-dihydro-1 H -inden-1-amine (1-aminoindan), 2,2′-(1,2-diaminoethane-1,2-diyl) diphenol (HPEN)] and perchlorate salts of α-amino acid esters [alanine benzyl ester (Ala-OBn), phenylalanine benzyl ester (Phe-OBn), phenylalanine methyl ester (Phe-OMe), phenylglycine methyl ester (PhGly-OMe), glutamic acid dibenzyl ester (Glu-diOBn), and valine benzyl ester (Val-OBn)]. The best enantioseparation was achieved in the case of PEA. The high enantioselectivity was rationalized by the strong π – π interaction of the extended π system of the aryl-substituted pyridine unit. [ABSTRACT FROM AUTHOR]

Chitosan is a biodegradable, biocompatible polymer of natural origin widely applied to the preparation of functional hydrogels suitable for controlled release of drugs, peptides and proteins. Non-covalent interactions, expecially ionic interactions, are the main driver of the loading and release behaviour of amino acids or peptides from chitosan hydrogels. With the aim to improve the understanding of the mechanisms governing the behaviour of chitosan hydrogels on peptide uptake and delivery, in this paper the attention was focused on the role played by sulfur on the interactions of chitosan hydrogels with sulfur-containing amino acids (AA) and peptides. Hence, loading and release experiments on cysteine, cystine and glutathione ( SH containing amino acid, dipeptide and tripeptide, respectively) as well as on glycine and valine as apolar amino acids were carried out. For these puroses, chitosan hydrogels were prepared in an easy and reproducible manner by a freeze-gelation process on a poly- l -lysine coated support. The hydrogel surface pore size, uniformity and distribution were tested. Optimal results ( D 50 = 26 ± 4 μm) were obtained by using the poly- l -lysine positively-charged surface. The loading results gathered evidenced that the sulfur-containing molecules presented an increased absorption both in terms of rate and extent by chitosan hydrogels with respect to nonpolar amino acids, mainly due to ionic and hydrogen bond interactions. ATR-FTIR analysis carried out on chitosan hydrogels, with and without the AA related compounds to study putative interactions, supported these apparent sulfur-dependent results. Finally, chitosan hydrogels displayed excellent retention capabilities (AA release <5%) for all AA, strongly supporting the use of chitosan hydrogels as matrix for controlled drug release. [ABSTRACT FROM AUTHOR]

The 20 standard amino acids (together with a few more that are not used in the biosynthesis of proteins) constitute a versatile tool box for synthesis of surfactants. Anionic, cationic and zwitterionic amphiphiles can be prepared and surfactants with several functional groups can be obtained by the proper choice of starting amino acid. This review gives examples of procedures used for preparation and discusses important physicochemical properties of the amphiphiles and how these can be taken advantage of for various applications. Micelles with a chiral surface can be obtained by self-assembly of enantiomerically pure surfactants and such supramolecular chirality can be utilized for asymmetric organic synthesis and for preparation of mesoporous materials with chiral pores. Surfactants based on amino acids with two carboxyl groups are effective chelating agents and can be used as collectors in mineral ore flotation. A surfactant based on cysteine readily oxidizes into the corresponding cystine compound, which can be regarded as a gemini surfactant. The facile and reversible cysteine-cystine transformation has been taken advantage of in the design of a switchable surfactant. A very attractive aspect of surfactants based on amino acids is that the polar head-group is entirely natural and that the linkage to the hydrophobic tail, which is often an ester or an amide bond, is easily cleaved. The rate of degradation can be tailored by the structure of the amphiphile. The ester linkage in betaine ester surfactants is particularly susceptible to alkaline hydrolysis and this surfactant type can be used as a biocide with short-lived action. This paper is not intended as a full review on the topic. Instead it highlights concepts that are unique to amino acid-based surfactants and that we believe can have practical implications. [ABSTRACT FROM AUTHOR]

Objectives Regular and accurate monitoring of blood phenylalanine (Phe) and tyrosine (Tyr) levels is prerequisite for a successful management of patients with hyperphenylalaninemia (HPA). We aimed to compare the tandem mass spectrometry (MS/MS) and the amino acid analyzer (AAA) as methods to measure blood Phe and Tyr levels and Phe/Tyr ratio. Methods Venous blood samples were collected for the AAA analysis, using Pinnacle PCX (Pickering Laboratories), with HPLC Series 1200 (Agilent). Capillary blood was spotted directly on filter paper (Whatman 903) for the MS/MS analysis, using 3200 QTrap AB SCIEX and Perkin Elmer Series 200 HPLC system. The Bland–Altman test was used to compare agreement between the methods and Pearson correlation coefficient to assess the association between the methods. Results 207 pairs of measurements were performed. The Phe levels (range 0–2500 μM) obtained by the MS/MS were on average 26.1% (SD 13.9%) lower compared to those obtained by the AAA. The Tyr levels by the MS/MS were on average 15.5% (SD 20.6%) lower. The Phe/Tyr ratio by the MS/MS was on average 10.6% (SD 15.9%) lower. The Pearson correlation coefficients for Phe (range 0–2500 μM), Tyr and the Phe/Tyr ratio were 0.984 ( p < 0.001), 0.841 ( p < 0.001) and 0.987 ( p < 0.001) respectively. Conclusions When monitoring blood Phe and Tyr levels in patients with HPA, clinicians need to be informed about the method used. Due to the considerable inter-assay variability, a single method is preferable for long-term follow-up of patients. When using MS/MS, on average 26% lower blood Phe levels were obtained as compared to the AAA. The guidelines and recommendations on HPA management should take into consideration the differences in laboratory methods. [ABSTRACT FROM AUTHOR]

This paper described a facile and direct electrochemical method for the determination of ultra-trace Cu 2+ by employing amino-functionalized mesoporous silica (NH 2 -MCM-41) as enhanced sensing platform. NH 2 -MCM-41 was prepared by using a post-grafting process and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy. NH 2 -MCM-41 modified glassy carbon (GC) electrode showed higher sensitivity for anodic stripping voltammetric (ASV) detection of Cu 2+ than that of MCM-41 modified one. The high sensitivity was attributed to synergistic effect between MCM-41 and amino-group, in which the high surface area and special mesoporous morphology of MCM-41 can cause strong physical absorption, and amino-groups are able to chelate copper ions. Some important parameters influencing the sensor response were optimized. Under optimum experimental conditions the sensor linearly responded to Cu 2+ concentration in the range from 5 to 1000 ng L −1 with a detection limit of 0.9 ng L −1 (S/N = 3). Moreover, the sensor possessed good stability and electrode renewability. In the end, the proposed sensor was applied for determining Cu 2+ in real samples and the accuracy of the results were comparable to those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) method. [ABSTRACT FROM AUTHOR]

[Display omitted] • A technical study of paints based on ovalbumine-drying oil mixtures is carried out. • Detection of proteins can be hampered when these are applied in mixture with drying oils. • A new procedure with two hydrolysis steps was implemented for GC–MS analysis of proteins. • Ovalbumine affects the curing of linseed oil. • Hypothesis on copolymeristaion between drying oils and ovalbumine is proposed. In this paper we present the technical study of protein-drying oil mixtures in the paint formulation of original manufacturers paint tubes from Fabbrica di colori per Belle Arti Maimeri dating back to the 1950s. The study is part of a wider research project aimed at understanding the chemistry of protein-drying oil mixtures, and how the oil curing in the presence of proteins may affects the protein analysis with mass spectrometric based techniques. Tempera grassa , according to traditional Late Medieval and Renaissance painting techniques, entails the use, as paint binder, of a mixture of a drying oil with a water miscible medium, commonly egg. The paints analysed in this study were, according to technical documentation available at the manufacturer, based on a mixture of linseed oil, ovalbumin and mastic resin. All the components of the paints were detected but proteins proved very challenging. They could not be detected by pyrolysis coupled to gas chromatography-mass spectrometry, nor by using classical procedures for gas chromatography – mass spectrometry analysis of amino acids after hydrolysis. A new analytical procedure based on two subsequent hydrolysis steps assisted by microwaves was implemented and proved to be successful. The first step with trifluoroacetic acid was aimed at a partial hydrolysis of proteins into peptides, for their efficient extraction. The second with hydrochloric acid in the vapour phase was used for a complete hydrolysis of peptides into amino acids for the GC–MS analysis. Linking experimental results on the tempera grassa paints to data obtained on the curing of oil/protein mixtures in paint mock-ups, the hypothesis that copolymerisation of proteins and the oil has taken place is proposed, and a discussion on how this may affect protein detection is carried out. [ABSTRACT FROM AUTHOR]

Amino acids in rain samples offer important information on their origin and roles in biogeochemical cycling. This paper describes the development and validation of an alternative analytical procedure for amino acids in atmospheric precipitation using gas chromatography coupled with mass spectrometry (GC–MS). The method detection limits (MDLs) of these amino acids ranged from 1.46 ng L−1 (Proline) to 135 ng L−1 (Arginine), which were much lower than previous methods like high-performance liquid chromatography (HPLC) and comparable to those with liquid chromatography-tandem mass spectrometry (LC-MS/MS). None of the target analytes were detected in blank samples, which was attributed to the optimized pretreatment protocol we adopted. We conclude that the GC–MS based technique developed in this study possesses advantage due to low detection limits. We further demonstrate the applicability of this method by analyzing rain samples from the background atmosphere of the Tibetan Plateau (TP). Similar relative abundances of amino acids were found in the TP rains, marine rains and Arctic ice. The correlations between FAAs and water- soluble ions in the Tibetan Plateau rainwaters showed that the FAAs were most likely originated from biomass burning. Given the similarity of snow and rain samples, our method also provides potential for the future analysis of amino acids in glacier ice cores. • A GC–MS analytical method for amino acids in precipitation was performed and optimized. • The developed method was characterized with high sensitivity and selectivity, while low blank value. • This is the first time that free amino acids were determined in the Tibetan Plateau rain. [ABSTRACT FROM AUTHOR]

Low-cost, high-throughput, broadly useful photoresponsive enantiomeric excess (ee) sensing of amino acids remains challenging to date. Herein, based on the selective oxidation reaction of amino acid oxidase (AAO) to amino acid enantiomers (D/L-AA) and the oxidation reaction of substrate (H 2 O 2) with aromatic boronic ester, we put forward a photoresponsive strategy for the determination of D/L-AA at a certain concentration. In this scheme, the substrate H 2 O 2 produced by the enzyme-catalyzed reaction was determined by sensitive fluorescent and colorimetric response of ethyl-3-(3-(benzothiazol-2-yl)-5-methyl-2-((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)oxy)phenyl)-2-cyanoacrylate (HBT-PB) to reflect the enantiomeric content at a certain concentration. The photoresponsive probe HBT-PB was readily available and inexpensive with sensitive long-wavelength red fluorescence and colorimetric light response to H 2 O 2 , the detection limit (LOD) was estimated as 2.91 μM. The operation of the sensing method was simple and data collection and processing are straightforward. The practicability of the scheme was favorably confirmed by accurate and scientific analysis of methionine and Dopa samples. As a result, the scheme was not only suitable for high-throughput screening but also adaptable to low-cost and sensitive RGB colorimetric analysis platform (LOD of methionine and Dopa was calculated as 9.23 μM and 8.34 μM respectively) with modern plate readers, and possessed extremely high enantioselectivity and wide applicability which benefited from the specificity and efficiency of enzyme catalytic reaction. In this paper, A novel strategy of combining the highly specific chiral catalytic reaction of LAAO to amino acid enantiomers and the special photoresponse of the designed HBT-PB probe to H 2 O 2 is developed for the detection of amino acid enantiomeric excess. Image 1 • A novel enantiomeric detection platform was developed for amino acid and Dopa. • The probe is available with sensitive fluorescent and colorimetric light response. • This scheme is suitable for high-throughput screening and RGB colorimetric analysis. • The proposed method has extremely high enantioselectivity and wide applicability. [ABSTRACT FROM AUTHOR]

• Supercritical fluid chromatography and enhanced fluidity liquid chromatography. • Free amino acids, peptides, proteins and nucleic acid bricks. • Mobile phases of CO 2 and co-solvent, comprising water and additives. • Detection issues and hyphenation to mass spectrometry. • Applications in foodomics, metabolomics, clinical and pharmaceutical areas. Biomolecules like proteins, peptides and nucleic acids widely emerge in pharmaceutical applications, either as synthetic active pharmaceutical ingredients, or from natural products as in traditional Chinese medicine. Liquid-phase chromatographic methods (LC) are widely employed for the analysis and/or purification of such molecules. On another hand, to answer the ever-increasing requests from scientists involved in biomolecules projects, other chromatographic methods emerge as useful complements to LC. In particular, there is a growing interest for chromatography with a mobile phase comprising pressurized carbon dioxide, which can be named either (i) supercritical (or subcritical) fluid chromatography (SFC) when CO 2 is the major constituent of the mobile phase, or (ii) enhanced fluidity liquid chromatography (EFLC) when hydro-organic or purely organic solvents are the major constituents of the mobile phase. Despite the low polarity of CO 2 , supposedly inadequate to solubilize such biomolecules, SFC and EFLC were both employed in many occasions for this purpose. This paper specifically reviews the literature related to the SFC/EFLC analysis of free amino acids, peptides, proteins, nucleobases, nucleosides and nucleotides. The analytical conditions employed for specific molecular families are presented, with a focus on the nature of the stationary phase and the mobile phase composition. We also discuss the potential benefits of combining SFC/EFLC to LC in a single gradient elution, a method sometimes designated as unified chromatography (UC). Finally, detection issues are presented, and more particularly hyphenation to mass spectrometry. [ABSTRACT FROM AUTHOR]

As part of the green concept, biorenewable deep eutectic solvent has emerged as an appealing type of ionic liquid and has shown their advance as environmentally benign sustainable alternative to the conventional solvents in the deep utilization of natural polymers, such as cellulose and lignin, which contributes to alleviating the pressure of the reduction of non-renewable resource. However, it has been few studies related to the value increase of another abundant natural polymer-protein material. As a representative, keratin fiber is a renewable biopolymer with excellent biocompatibility and biodegradability, but the poor surface performance results it is difficult to be functional modified, and the application is also limited in the textile industry. In this paper, the dissolution was controlled on the wool fiber surface using an eco-friendly and biorenewable deep eutectic solvent (DES). Surface dissolution is different from those used in previous studies and has been investigated in detail for the first time. The results show that a fast and facile surface dissolution process could be reached by incubating the wool fiber in DES for 10 min and the DES can be reused more than 10 times. Allwörden reaction, SEM and AFM images show that the controlled dissolution on the fiber surface was successfully accomplished. This process was also accompanied by the dissolution of amino acids and cleavage of disulfide bonds, which were ascertained using Raman spectroscopy, XPS and amino acid analysis. The protein macromolecular backbone and secondary structure of the surface-dissolved wool were not lost using FTIR spectroscopy, XRD and NMR spectroscopy. The modified wool by DES method has better surface properties; moreover, the method offers a more cost-effective and sustainable alternative for the modification of protein material. Unlabelled Image • The natural protein fiber is controllably surface dissolved by biorenewable DES. • The treatment time was shorten to 10 min further compared with previous methods. • The water contact angle of fiber decreased below 90o after the dissolution. • The DES can be recycled and reused more than 10 times. • The mechanism of surface dissolution in the DES was proposed. [ABSTRACT FROM AUTHOR]

Ancient proteomics is being applied to samples dating further and further back in time, with many palaeontological specimens providing protein sequence data for phylogenetic analysis as well as protein degradation studies. However, fossils are a precious material and proteomic analysis is destructive and costly. In this paper we consider three different techniques (ATR-FTIR, MALDI-ToF MS and chiral AA analysis) to screen fossil material for potential protein preservation, aiming to maximise the proteomic information recovered and saving costly time consuming analyses which may produce low quality results. It was found that splitting factor and C/P indices from ATR-FTIR were not a reliable indicator of protein survival as they are confounded by secondary mineralisation of the fossil material. Both MALDI-ToF MS and chiral AA analysis results were able to successfully identify samples with surviving proteins, and it is suggested that one or both of these analyses be used for screening palaeontological specimens. This study has shown both chiral amino acid analysis and MALDI-ToF MS are reliable screening methods for predicting protein survival in fossils. Both these methods are quick, cheap, minimally destructive (1 mg and 15 mg respectively) and can provide crucial additional information about the endogeneity of the surviving proteins. It is hoped that the use of these screening methods will encourage the examination of a wide range of palaeontological specimens for potential proteomic analysis. This in turn will give us a better understanding of protein survival far back in time and under different environmental conditions. Unlabelled Image • ATR-FTIR, Chiral amino acid (AA) analysis and MALDI-ToF MS were tested as screening methods for palaeoproteomics. • Am/P was shown to be the best criterion to assess protein survival when using ATR-FTIR. • AA analysis and MALDI-ToF MS results show a good correlation with protein survival [ABSTRACT FROM AUTHOR]