1
|
Xu RB, Yang X, Wang J, Zhao HT, Lu WH, Cui J, Cheng CL, Zou P, Huang WW, Wang P, Li WJ, Hu XL. Chemical composition and antioxidant activities of three polysaccharide fractions from pine cones. Int J Mol Sci 2012. [PMID: 23203063 PMCID: PMC3509579 DOI: 10.3390/ijms131114262] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The traditional method of gas chromatography-mass spectrometry for monosaccharide component analysis with pretreatment of acetylation is described with slight modifications and verified in detail in this paper. It was then successfully applied to the quantitative analysis of component monosaccharides in polysaccharides extracted from the pine cones. The results demonstrated that the three pine cone polysaccharides all consisted of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios. According to the recovery experiment, the described method was proved accurate and practical for the analysis of pine cone polysaccharides, meeting the need in the field of chemical analysis of Pinus plants. Furthermore; the chemical characteristics, such as neutral sugar, uronic acids, amino acids, molecular weights, and antioxidant activities of the polysaccharides were investigated by chemical and instrumental methods. The results showed that the chemical compositions of the polysaccharides differed from each other, especially in the content of neutral sugar and uronic acid. In the antioxidant assays, the polysaccharide fractions exhibited effective scavenging activities on ABTS radical and hydroxyl radical, with their antioxidant capabilities decreasing in the order of PKP > PAP > PSP. Therefore, although the polysaccharide fractions had little effect on superoxide radical scavenging, they still have potential to be developed as natural antioxidant agents in functional foods or medicine.
Collapse
Affiliation(s)
- Ren-Bo Xu
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Xin Yang
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
- Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standard & Testing Technology for Agro-Product, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South Street, Haidian District, Beijing 100081, China
- Authors to whom correspondence should be addressed; E-Mails: (X.Y.); (J.W.); Tel.: +86-451-86282910 (X.Y.); Fax: +86-451-86282906 (X.Y.)
| | - Jing Wang
- Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standard & Testing Technology for Agro-Product, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South Street, Haidian District, Beijing 100081, China
- Key Laboratory of Agrifood Safety and Quality, Ministry of Agriculture, No.12 Zhongguancun South Street, Haidian District, Beijing 100081, China
- Authors to whom correspondence should be addressed; E-Mails: (X.Y.); (J.W.); Tel.: +86-451-86282910 (X.Y.); Fax: +86-451-86282906 (X.Y.)
| | - Hai-Tian Zhao
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Wei-Hong Lu
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Jie Cui
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Cui-Lin Cheng
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Pan Zou
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Wei-Wei Huang
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Pu Wang
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Wen-Jing Li
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| | - Xing-Long Hu
- School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, China; E-Mails: (R.-B.X.); (H.-T.Z.); (W.-H.L.); (J.C.); (C.-L.C.); (P.Z.); (W.-W.H.); (P.W.); (W.-J.L.); (X.-L.H.)
| |
Collapse
|
2
|
Ruiz-Matute AI, Hernández-Hernández O, Rodríguez-Sánchez S, Sanz ML, Martínez-Castro I. Derivatization of carbohydrates for GC and GC-MS analyses. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 879:1226-40. [PMID: 21186143 DOI: 10.1016/j.jchromb.2010.11.013] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/29/2010] [Accepted: 11/08/2010] [Indexed: 11/26/2022]
Abstract
GC and GC-MS are excellent techniques for the analysis of carbohydrates; nevertheless the preparation of adequate derivatives is necessary. The different functional groups that can be found and the diversity of samples require specific methods. This review aims to collect the most important methodologies currently used, either published as new procedures or as new applications, for the analysis of carbohydrates. A high diversity of compounds with diverse functionalities has been selected: neutral carbohydrates (saccharides and polyalcohols), sugar acids, amino and iminosugars, polysaccharides, glycosides, glycoconjugates, anhydrosugars, difructose anhydrides and products resulting of Maillard reaction (osuloses, Amadori compounds). Chiral analysis has also been considered, describing the use of diastereomers and derivatives to be eluted on chiral stationary phases.
Collapse
Affiliation(s)
- A I Ruiz-Matute
- Instituto de Fermentaciones Industriales-CIAL (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | | | | | | | | |
Collapse
|
3
|
Wunschel DS, Colburn HA, Fox A, Fox KF, Harley WM, Wahl JH, Wahl KL. Detection of agar, by analysis of sugar markers, associated with Bacillus anthracis spores, after culture. J Microbiol Methods 2008; 74:57-63. [PMID: 18538426 DOI: 10.1016/j.mimet.2008.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 04/07/2008] [Indexed: 11/28/2022]
Abstract
Detection of small quantities of agar associated with spores of Bacillus anthracis could provide key information regarding its source or growth characteristics. Agar, widely used in growth of bacteria on solid surfaces, consists primarily of repeating polysaccharide units of 3,6-anhydro-l-galactose (AGal) and galactose (Gal) with sulfated and O-methylated galactoses present as minor constituents. Two variants of the alditol acetate procedure were evaluated for detection of potential agar markers associated with spores. The first method employed a reductive hydrolysis step, to stabilize labile anhydrogalactose, by converting to anhydrogalactitol. The second eliminated the reductive hydrolysis step simplifying the procedure. Anhydrogalactitol, derived from agar, was detected using both derivatization methods followed by gas chromatography-mass spectrometry (GC-MS) analysis. However, challenges with artifactual background (reductive hydrolysis) or marker destruction (hydrolysis) respectively lead to the use of an alternative agar marker. A minor agar component, 6-O-methyl galactose (6-O-M gal), was readily detected in agar-grown but not broth-grown bacteria. Detection was optimized by the use of gas chromatography-tandem mass spectrometry (GC-MS-MS). With appropriate choice of sugar marker and analytical procedure, detection of sugar markers for agar has considerable potential in microbial forensics.
Collapse
Affiliation(s)
- David S Wunschel
- Chemical and Biological Sciences, Pacific Northwest National Laboratory, Richland, WA 99352, United States.
| | | | | | | | | | | | | |
Collapse
|
4
|
Villas-Bôas SG, Mas S, Akesson M, Smedsgaard J, Nielsen J. Mass spectrometry in metabolome analysis. MASS SPECTROMETRY REVIEWS 2005; 24:613-46. [PMID: 15389842 DOI: 10.1002/mas.20032] [Citation(s) in RCA: 356] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In the post-genomic era, increasing efforts have been made to describe the relationship between the genome and the phenotype in cells and organisms. It has become clear that even a complete understanding of the state of the genes, messages, and proteins in a living system does not reveal its phenotype. Therefore, researchers have started to study the metabolome (or the metabolic complement of functional genomics). Within this context, mass spectrometry (MS) has increasingly occupied a central position in the methodologies developed for determination of the metabolic state. This review is mainly focused on the status of MS in the metabolome field, trying to direct the reader to the main approaches for analysis of metabolites, reviewing basic methodologies in sample preparation, and the most recent MS techniques introduced. Apart from the description of the different methods, this review will try to state a general comparison between the several different techniques that involve MS and metabolite analysis, and will highlight their limitations and preferred applicability.
Collapse
Affiliation(s)
- Silas G Villas-Bôas
- Center for Microbial Biotechnology, BioCentrum-DTU, Technical University of Denmark, Building 223, DK-2800 Kgs. Lyngby, Denmark
| | | | | | | | | |
Collapse
|
5
|
Valentine N, Wunschel S, Wunschel D, Petersen C, Wahl K. Effect of culture conditions on microorganism identification by matrix-assisted laser desorption ionization mass spectrometry. Appl Environ Microbiol 2005; 71:58-64. [PMID: 15640170 PMCID: PMC544247 DOI: 10.1128/aem.71.1.58-64.2005] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used to identify bacteria based upon protein signatures. This research shows that while some different proteins are produced by vegetative bacteria when they are cultured in different growth media, positive identification with MALDI-TOF MS is still possible with the protocol established at the Pacific Northwest National Laboratory (K. H. Jarman, S. T. Cebula, A. J. Saenz, C. E. Petersen, N. B. Valentine, M. T. Kingsley, and K. L. Wahl, Anal. Chem. 72:1217-1223, 2000). A core set of small proteins remain constant under at least four different culture media conditions and blood agar plates, including minimal medium M9, rich media, tryptic soy broth (TSB) or Luria-Bertani (LB) broth, and blood agar plates, such that analysis of the intact cells by matrix-assisted laser desorption/ionization mass spectrometry allows for consistent identification.
Collapse
Affiliation(s)
- Nancy Valentine
- Pacific Northwest National Laboratory, P.O. Box 999, Battelle Blvd., K210, Richland, WA 99352, USA.
| | | | | | | | | |
Collapse
|
6
|
Cao Y, Wang Y, Chen X, Ye J. Study on sugar profile of rice during ageing by capillary electrophoresis with electrochemical detection. Food Chem 2004. [DOI: 10.1016/j.foodchem.2003.12.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Fox A, Stewart GC, Waller LN, Fox KF, Harley WM, Price RL. Carbohydrates and glycoproteins of Bacillus anthracis and related bacilli: targets for biodetection. J Microbiol Methods 2003; 54:143-52. [PMID: 12782370 DOI: 10.1016/s0167-7012(03)00095-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The spore is the form released in a bioterrorism attack. There is a real need for definition of new targets for Bacillus anthracis that might be incorporated into emerging biodetection technologies. Particularly of interest are macromolecules found in B. anthracis that are (1) spore-specific, (2) readily accessible on the spore surface and (3) distinct from those present in related organisms. One of the few biochemical methods to identify the spores of B. anthracis is based on the presence of rhamnose and 3-O-methyl rhamnose as determined by gas chromatography-mass spectrometry. Related organisms additionally contain 2-O-methyl rhamnose and fucose. Carbohydrates and glycoproteins of the B. cereus group of organisms and the related B. subilis group are reviewed here. It is hypothesized that the spore-specific carbohydrate is a component of the newly described glycoprotein of the exosporium of B. anthracis. Further work to define the protein and carbohydrate components of the glycoprotein of B. anthracis could be highly useful in developing new technologies for rapid biodetection.
Collapse
Affiliation(s)
- Alvin Fox
- Department of Pathology and Microbiology, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
| | | | | | | | | | | |
Collapse
|
8
|
El-Helow ER. Identification and molecular characterization of a novel Bacillus strain capable of degrading Tween-80. FEMS Microbiol Lett 2001; 196:119-22. [PMID: 11267766 DOI: 10.1111/j.1574-6968.2001.tb10551.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
A Tween-80-degrading novel marine Bacillus strain, N10, has recently been isolated in Alexandria University, Egypt. The taxonomic position of this endospore forming bacterium was investigated on the basis of fatty acid analysis and 16S rRNA gene sequencing. Comparative computer database analyses revealed that the bacterium is a Bacillus subtilis strain. The gene encoding the small acid-soluble protein gamma-type (SASP-B), sspE, was successfully utilized in this study as a tool for discrimination between the two B. subtilis subspecies W23 and 168. Based on the alignment of 16S rRNA sequences and analysis of SASP-B relatedness, it has been demonstrated that the novel marine B. subtilis strain N10 is more closely related to the B. subtilis reference strain W23 than to 168. The strain, N10, has been deposited in the Bacillus Genetic Stock Center (BGSC) and assigned the accession number 3A17.
Collapse
Affiliation(s)
- E R El-Helow
- Department of Botany, Faculty of Science, University of Alexandria, Alexandria 21526, Egypt.
| |
Collapse
|
9
|
Johnson YA, Nagpal M, Krahmer MT, Fox KF, Fox A. Precise molecular weight determination of PCR products of the rRNA intergenic spacer region using electrospray quadrupole mass spectrometry for differentiation of B. subtilis and B. atrophaeus, closely related species of bacilli. J Microbiol Methods 2000; 40:241-54. [PMID: 10802141 DOI: 10.1016/s0167-7012(00)00127-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Assessment of 16S-23S rRNA intergenic spacer region (ISR) sequence variability is an important supplement to 16S rRNA sequencing for differentiating closely related bacterial species. Species differentiation can also be achieved by determination of approximate size of PCR (polymerase chain reaction) products of ISRs, based on their relative electrophoretic mobility on agarose gels. Closely-related species can have ISR PCR products that are similar in size. More precise molecular weight (M.W.) determination of these products might allow improved discrimination of such species. Electrospray quadrupole mass spectrometry (ESI-Q-MS) has the potential to provide such precision. For ESI-Q-MS analysis, size limitation of PCR products is currently limited to around 130 base pairs (bp). Bacillus subtilis and Bacillus atrophaeus are two closely related species with few distinguishing phenotypic characteristics. B. subtilis has recently been sub-divided into two subgroups, W23 (type strain, W23) and 168 (type strain, 168). PCR products amplified from the ISR including the 5' terminal end of the 23S rRNA and a conserved portion of the ISR were analyzed by ESI-Q-MS. A 119 or 120 bp PCR product was produced for B. atrophaeus strains. However, strains of B. subtilis subgroups W23 and 168 each produced 114 bp products. In summary, a mass spectrometry method was developed for differentiation of B. subtilis and B. atrophaeus. Also, the genetic similarity of B. subtilis subgroups W23 and 168 was confirmed. Accurate determination of the molecular weight of PCR products from the 16S-23S rRNA intergenic spacer region using electrospray quadrupole mass spectrometry has great potential as a general technique for characterizing closely related bacterial species.
Collapse
Affiliation(s)
- Y A Johnson
- Department of Microbiology and Immunology, University of South Carolina, School of Medicine, Columbia, SC, USA
| | | | | | | | | |
Collapse
|
10
|
Song Y, Yang R, Guo Z, Zhang M, Wang X, Zhou F. Distinctness of spore and vegetative cellular fatty acid profiles of some aerobic endospore-forming bacilli. J Microbiol Methods 2000; 39:225-41. [PMID: 10670769 DOI: 10.1016/s0167-7012(99)00123-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A gas chromatographic analysis method was employed to determine the cellular fatty acid (CFA) profiles of spores and vegetative cells of some aerobic endospore-forming bacilli. The harvests of experimental strains were processed to obtain pure spores and acquire whole cell fatty acid methyl esters for the subsequent gas chromatographic analysis, and the corresponding vegetative cells were set as control. Evaluation of reproducibility of spore CFA components revealed that, provided under standardized experimental procedure, spore CFA composition was stable enough for research purposes. Fatty acids recovered in spores in greater quantities were saturated branched-chain acids containing 15 and 17 carbon atoms, similar to the vegetative cells. Commonly, the proportions of saturated branched-chain acids in spores were greater than in vegetative cells. The dendrograms obtained by cluster analysis provided some meaningful taxonomic information of the experimental strains. The fatty acids analysis of spores seems to be a promising supplementary tool for the chemotaxonomic research of aerobic endospore-forming bacilli.
Collapse
Affiliation(s)
- Y Song
- Laboratory for Analytical Microbiology, National Center of Biomedical Analysis, Institute of Microbiology and Epidemiology, Fengtai District, Beijing, PR China
| | | | | | | | | | | |
Collapse
|
11
|
Fox A. Carbohydrate profiling of bacteria by gas chromatography-mass spectrometry and their trace detection in complex matrices by gas chromatography-tandem mass spectrometry. J Chromatogr A 1999; 843:287-300. [PMID: 10399857 DOI: 10.1016/s0021-9673(98)00884-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacterial cellular polysaccharides are composed of a variety of sugar monomers. These sugars serve as chemical markers to identify specific species or genera or to determine their physiological status. Some of these markers can also be used for trace detection of bacteria or their constituents in complex clinical or environmental matrices. Analyses are performed, in our hands, employing hydrolysis followed by the alditol acetate derivatization procedure. Substantial improvements have been made to sample preparation including simplification and computer-controlled automation. For characterization of whole cell bacterial hydrolysates, sugars are analyzed by gas chromatography-mass spectrometry (GC-MS). Simple chromatograms are generated using selected ion monitoring (SIM). Using total ion GC-MS, sugars can be readily identified. In more complex clinical and environmental samples, markers for bacteria are present at sufficiently low concentrations that more advanced instrumentation, gas chromatography-tandem mass spectrometry (GC-MS-MS), is preferred for optimal analysis. Using multiple reaction monitoring, MS-MS is used (replacing more conventional SIM) to ignore extraneous chromatographic peaks. Triple quadrupole and ion trap GC-MS-MS instruments have both been used successfully. Absolute chemical identification of sugar markers at trace levels is achieved, using MS-MS, by the product spectrum.
Collapse
Affiliation(s)
- A Fox
- Department of Microbiology and Immunology, University of South Carolina (USC), School of Medicine, Columbia 29208, USA.
| |
Collapse
|
12
|
Benfenati E, Pierucci P, Fanelli R, Preiss A, Godejohann M, Astratov M, Levsen K, Barceló D. Comparative studies of the leachate of an industrial landfill by gas chromatography-mass spectrometry, liquid chromatography-nuclear magnetic resonance and liquid chromatography-mass spectrometry. J Chromatogr A 1999; 831:243-56. [PMID: 10070765 DOI: 10.1016/s0021-9673(98)00949-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nowadays, the need to have a realistic characterization of industrial effluents in the environment has become more and more recognized. A palette of different analytical methods both for sample extraction and instrumental analysis are available today, some older, others introduced more recently. The aim of this research is to compare a number of these techniques. To do this we studied a real leachate from an industrial landfill and carried out chemical analyses for organic pollutants, using different extraction methods based on solid-phase extraction and solid-phase microextraction and different instrumental techniques such as GC-MS, LC-MS, NMR and LC-NMR. Results show the performances of the different techniques, which are complementary.
Collapse
Affiliation(s)
- E Benfenati
- Dipartimento Ambiente e Salute, Istituto di Ricerche Farmacologiche Mario Negri Milan, Italy
| | | | | | | | | | | | | | | |
Collapse
|