Recent applications of vibrational mid-Infrared (IR) spectroscopy for studying soil components: a review

The present review highlights the recent applications of mid-infrared spectroscopy and in particular of diffuse reflectance spectroscopy (DRIFT) and attenuated total reflectance (ATR) and processing methods (e.g., deconvolution, derivative and chemometrics) to rapidly provide valuable information on soil composition and organic geochemistry. Research has demonstrated that both DRIFT and ATR techniques can be considered useful tools for the analysis of a large number of soil samples, giving not only typical spectral patterns but permitting an accurate prediction of quantitative parameters such as, e.g., total carbon, total nitrogen, C/Nratio, lignin, dissolved OC, carbonyl-C, aromatic-C, O-alkyl-C, and alkyl-C contents.Based on literature results, infrared spectroscopy can be recognized as one of the most promising analytical techniques for investigating soil science

Testing a bovine blood-derived compound as iron supply on cucumis sativus L.

A new powder formulation obtained from bovine blood (Fe-heme) was tested on cucumber (Cucumis sativus L.) to investigate its effectiveness as iron supply in comparison with two synthetic iron-chelates fertilizers: ethylenediaminetetraacetic acid (EDTA/Fe3+) and ethylenediamine-N'N'-bis(2-hydroxyphenyl acetic acid) (o,oEDDHA/Fe3+). Green stressed cucumber plants were evaluated in their recovery (SPAD index and weight variations) and to test the iron reduction capacity of the roots at pH 7.5 and 6.0 using each iron treatment as iron supply. The blood-derived product showed similar effects on decreasing iron-deficiency symptoms: SPAD increments and the weights of plants were similar. Noteworthy, the average of Fe3+reduction capacity in roots was higher for EDTA/Fe3+, while it was similar for o,oEDDHA/Fe3+, and Fe-heme at pH 7.5. Fe-heme showed a complex behavior due to aggregation and low solubility at pH 6 and showed an unexpectedly high contribution of root exudates to iron reductionThis research was funded by EUROPEAN SCIENCE FOUNDATION (ESF) within the framework of the ESF activity “The Functionality of Iron Minerals in Environmental Processes” (scholarship to Michele Di Foggia) [grant number:4213] and by the Spanish MINECO project AGL2013-44474-R

DSC and Raman study of DMPC liposomes in presence of Ibuprofen at different pH

Ibuprofen (IbuH), 2-(4-isobutylphenyl) propionic acid, is a well-known nonsteroidal anti-inflammatory drug and is a promising antiatherosclerotic agent. Since IbuH has demonstrated to affect cell membranes structure, the study of the interaction between the membrane components, like phospholipids, and the drug, is of paramount interest. Moreover, liposomes can be used as drug carriers. In this paper, the effect of increasing amounts of Ibuprofen at neutral and acidic pH on the behaviour of dimyristoylphosphatidylcholine (DMPC) liposomes was investigated by means of Raman and differential scanning calorimetry (DSC) techniques. The results showed that pH influenced noticeably the liposome structure. A simple ‘solution-like’ model can explain the system when small or high IbuH or IbuNa (IbuH sodium salt forming at neutral and basic pH) amounts are present (IbuH/DMPC molar ratio ≤1/8.3 or ≥1/2.2 or IbuNa/DMPC molar ratio ≤1/17.5 or ≥1/4), whereas at intermediate amounts, two DSC peaks appeared: these systems could be described as a mixture of ‘phase II’ domains inserted within a structure of smaller and further ramified ‘phase I’ domains. Both DSC and Raman data suggested IbuH can penetrate within the apolar bilayer at pH 3, while at pH 7, the setting up of polar interactions of different strength between the carboxylic groups of IbuNa and the choline head of the DMPC, hamper a further penetration of the drug. Similar results were obtained both inserting directly IbuH molecules into liposomes as well as acidifying IbuNa water solutions, suggesting a possible use of liposomes as drug carriers when polarity is pH dependent

Effects of two Lignosulfonate-Humates on Zea mays L. Metabolism

Two lignosulfonate-humates (a and b), derived by an industrial process from lignin, were chemically characterized and their effects on maize plants in terms of growth, nitrogen metabolism and photosynthesis were investigated. The biological effects of lignosulfonate humates were compared with those induced by a humic acid extracted from leonardite in order to better understand the complexity of their biological effects. Our results displayed that both lignosulfonate-humates (a and b) had a hormone-like activity and increased root and leaf growth. Moreover, all treatments increased the content of chlorophyll, glucose and fructose and enhanced the activity of Rubisco, glutamine-synthetase and glutamate-synthase. The observed intense biological activity indicated that lignosulfonate-humates and leonardite humic acid had a positive role on photosynthetic process of maize plants. In the light of these results, lignosulfonate-humates may be used as biostimulants to increase crop yield

IR and Raman characterization of carcinine tautomers as a function of pH and copper (II) complex formation.

Carcinine (p-alanyl-histamine) (Care) is a natural imidazole-containing compound found in the non-protein fraction of mammalian tissues and probably involved in the carnosine-histidine-histamine metabolic pathway in physiologic response to stress. It has a good potential to act as a natural antioxidant in vivo since it is able to scavenge harmful "OH radicals and inhibit fatty acid peroxidation. One of the mechanism by which antioxidants protects targets from oxidative stress is the chelation of transition metals, such as copper, preventing them from participating in deleterious processes. The ability of Care to chelate copper ions was tested by a vibrational study of Care alone and its 1:1 complexes with Cu(II) ions at different pHs (7, 9 and 10). Both Raman and IR spectra present marker bands useful for analyzing the tautomeric equilibrium of the imidazole ring and identifying the complex structure predominating at a specific pH. Tautomer I (NT-H) is the preferred form of free Care both at neutral and basic pH (Raman and IR bands at ~ 1578, 1292 and 988 cm-1). In addition, free Care is able to form a strong network of H-bonds by its three differently protonated nitrogen atoms (-NHs+, peptidic -NH- and imidazolic >NH) and the peptidic C=O and/or the non-protonated N imidazolic atom. With regards the metal interaction, Care is a polydentate ligand offering four potential binding sites: the two imidazole nitrogen, the amino group and the peptide linkage. The presence of copper ions does not strongly affect the tautomerie equilibrium at neutral pH. The Raman bands of the imidazolic ring were observed at different wavenumbers (1596 and 972 cm-1) respect to free Care, indicating that tautomer I is involved in the coordination. By increasing pH, the deprotonation of both N-imidazolic nitrogens is induced, giving rise to metal imidazolate bridges. Both at neutral and basic pH the primary amine group takes part to the Cu chelation, whereas only under neutral conditions all the peptidic moieties are involved in coordination. Thus, Care acts as a tri-dentate ligand at neutral pH, mainly giving a monomeric complex, [CuLH-1], containing tautomer I. By increasing pH up to 10, an oligonuclear complex, probably [Cu4L4H4], with metal-imidazolate ions connecting different ligand molecules predominates

Crocus sativus Petals: Waste or Valuable Resource? The Answer of High-Resolution and High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance

Intact Crocus sativus petals were studied for the first time by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, revealing the presence of kinsenoside (2) and goodyeroside A (3), together with 3-hydroxy-γ-butyrolactone (4). These findings were confirmed by HR-NMR analysis of the ethanol extract of fresh petals and showed that, even though carried out rapidly, partial hydrolysis of glucopyranosyloxybutanolides occurs during extraction. On the other hand, kaempferol 3-O-sophoroside (1), which is "NMR-silent" in intact petals, is present in extracts. These results suggest to evaluate the utilization of saffron petals for phytopharmaceutical and nutraceutical purposes to exploit a waste product of massive production of commercial saffron and point to the application of HR-MAS NMR for monitoring bioactive compounds directly on intact petals, avoiding the extraction procedure and the consequent hydrolysis reaction

Caratteristiche metaboliche delle metastasi cerebrali valutate mediante spettroscopia di Risonanza Magnetica A 3T (1H-MRS).

Scopo del lavoro è il tentativo di individuare caratteristiche metaboliche specifiche delle metastasi cerebrali intra-assiali mediante Spettroscopia di Risonanza Magnetica de Protone (1H-MRS). Le metastasi cerebrali sono neoplasie che possono presentarsi con aspetti morfologici simili a quelli delle lesioni primitive dell'encefalo, in particolare dei gliomi ad alto grado di malignità. Abbiamo voluto verificare se la metodica di Spettroscopia possa fornire elementi utili alla diagnosi differenziale. Pazienti e metodi: vengono esaminate con 1H-MRS 5 metastasi cerebrali, verificate all'esame istologico postoperatorio. Gli esami RM sono stati eseguiti con apparecchiatura 3.0 Tesla whole-body scanner (General Electric Medicai Systems, Milwaukee, Wisconsin), con bobina 8 canali phased array. Gli spettri sono stati ottenuti con sequenza - Spin Echo (PRESS) con TR 2000 ms and TE 35 ms ed analizzati con il programma SAGE (General Electric Medical Systems). I dati spettroscopici sono stati confrontati con quelli ottenuti da neoplasie gliali maligne con aspetto morfologico simile a quello delle metastasi. Risultati e discussione: gli spettri delle 5 lesioni metastatiche erano caratterizzati dalla presenza di elevate quantità di Lipidi mobili e di Composti contenti Colina (Cho). Nei due casi di metastasi in cui il volume di interesse era posizionato anche all'interno della componente necrotico-cistica lo spettro evidenziava senza ambiguità la presenza di Lattato. Anche negli spettri dei gliomi maligni, caratterizzati da estese aree di necrosi, erano presenti molto intense le risonanze attribuite ai Lipidi mobili. In alcuni casi tuttavia in cui l'imaging non permetteva di differenziare la lesione intra-assiale maligna dalla metastasi, il pattern metabolico rivelato dalla Spettroscopia era fortemente indicativo di glioma maligno. La presenza infatti di Cho, Creatina (Cr) ed in particolare di N-acetilaspartato (NAA), metaboliti presenti nel tessuto cerebrale, anche se in concentrazioni alterate rispetto alla normalità, escludeva la presenza di una lesione secondaria. Conclusioni: in accordo con quanto riportato in letteratura i nostri dati confermano che le metastasi hanno un pattern metabolico caratterizzato da elevate concentrazioni di Cho e di Lipidi mobili. La possibilità di diagnosi differenziale fra metastasi e gliomi maligni era possibile in quei casi in cui la necrosi non era così massiva da rappresentare la caratteristica dominante dello spettro. L'aspetto metabolico dei due tipi di lesioni rispecchia infatti la loro diversa origine istologica

Raman and SERS study on cimetidine-metal complexes with biomedical interest

Cimetidine (cim) is one of the most potent histamine H2-receptor antagonists for inhibiting excessive acid secretion caused by histamine; it has been hypothesized that the therapeutic effects can be related to its interactions with metal ions. Raman spectra of the solid cim with Co(II), Cu(II), Ni(II) and Zn(II) metal complexes show that they can adopt two different structures: one is octahedral and the other, with Zn(II), is probably tetrahedral. The octahedral structure appears to be distorted both by the different metal ions as well as by the different anion present. The study was extended to very dilute solutions (ppm range) by using the surface-enhanced Raman scattering (SERS) technique, mimicking the physiological concentrations of cim and its metal complexes. SERS spectra suggest that, upon the binding of cim to silver colloids, the formation of stable 1 : 2 cim–metal complexes is excluded, the formation of 1 : 1 adduct appearingmore probable; in this product the metal reaches its total coordination shell by complexion with water molecules. To better explain the binding mechanism of cim to a metal (Ag) surface, we performed theoretical B3LYP calculations on cim alone aswell as on cim bonded to an Ag2 metal cluster in presence of water, observing a sufficiently good agreement between experimental and theoretical wavenumbers

Raman and SERS study on atrazine, prometryn and simetryn triazine herbicides

In the present study, we considered the Raman spectra of atrazine, prometryn and simetryn, in the solid form and in polar and apolar solvents, extending the investigation in the very diluted aqueous solutions (ppm) range by using the SERS technique. We performed theoretical calculations at the B3LYP/aug-ccpVQZ level on the three triazines, alone and in solution with polar and apolar solvents. An excellent agreement between theoretical and experimental frequencies was reached, with differences lying within few wavenumbers. The small differences observed can be ascribed to the solid crystalline phase and can be caused by local deviations in the uniformity of the crystalline field or to a coupling with lattice vibrations. Also the theoretical and experimental peak intensities well agreed and in most cases lied within \ub110%, the differences being ascribed to the local non-homogeneity of dielectric properties in the crystal. Moreover, this behavior confirmed the rigidity of the molecules and that their structure was not involved during the solution process. The theoretical SERS spectra at B3LYP/6-311+G(d,p) level of triazines bound to an Ag2 metal cluster offered an acceptable qualitative agreement with the experimental ones, suggesting that the stronger interaction site of triazines with Ag2 was on the less sterical hindered aromatic nitrogen atom, namely forming the N6 Ag2 molecular complex with atrazine, and the N2 Ag2 or N4 Ag2 molecular complexes with simetryn and prometryn. The agreement between calculated and experimental SERS spectra was not as good as that observed for the Raman spectra of pure compounds, but the trend of the theoretical spectra offered a useful guideline for the comprehension of the interaction sites and of the structural modification after adsorption on silver particles

Characterization of the lipids from human renal and urothelial neoplasms, by magnetic resonance spectroscopy and chromatography

This work reports a study on the characterization of the lipid obtained from cortical and medullary normal human kidney tissue, medullary tissue infiltrated by clear cell carcinomas (RCC), malignant renal neoplasms (RCC) and an urothelial carcinoma. The total lipid fractions were analyzed by 13C and 1H magnetic resonance spectroscopy and thin-layer chromatography, whereas the different lipid fractions were characterized by gas chromatography and high-performance liquid chromatography. The analysis evinced significant differences in the renal tissues here examined. It was confirmed that lipids obtained from healthy renal parenchyma are mainly composed by triglycerides, which are mostly formed by oleic and palmitoleic acids. Although the free cholesterol and phospholipid contents varied, phosphatidylcholine (PC) was the most representative phospholipid in all samples, as shown by the 13C NMR spectra. The medullary renal tissues infiltrated by RCC had considerable amounts of esterified cholesterol and free fatty acids, being higher in those areas that were closer to the neoplasm. The cortex renal tissues had a lower triglyceride level as compared to the medullary ones, but they exhibited significant amounts of α-tocopherol, Q10 coenzyme and phospholipids. The silica thin-layer chromatography (TLC) evinced the presence of esterified cholesterol and dolichols. Regarding RCC samples, they exhibited large amounts of esterified cholesterol, α-tocopherol, Q10 coenzyme, free fatty acids and phospholipids. In these neoplasms, PC was also the most representative phospholipids, and dolichols were detected in negligible amounts. On the other hand, the urothelial carcinoma displayed a quite different lipid profile as compared to that of the RCC. In fact, it showed low levels of triglycerides, whereas the TLC bands of squalene, dolichols, phospholipids, free and esterified cholesterol and fatty acids were particularly intense. These results confirm the potential role of esterified cholesterol as prognostic and diagnostic factor of neoplasies, with a particular capability to indicate the tumor diffusion in healthy renal parenchyma. This work also underlines the importance and great advantage of applying complementary techniques (such as spectroscopy and chromatography) to the analysis of lipids in neoplasms, providing a more complete and detailed profile of these components