Multivariate curve resolution–alternating least squares (MCR-ALS) applied to spectroscopic data from monitoring chemical reactions processes

Garrido, Mariano; Rius, F. Xavier; Larrechi, M. Soledad

doi:10.1007/s00216-008-1955-6

Cited by 229 publications

(140 citation statements)

References 103 publications

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“…NA, not applicable. (17). In both cases, the number of suggested components, which is defined based on the drop in eigenvalue, is used as the initial number of components i for MCR-ALS.…”

Section: Figmentioning

confidence: 99%

Bifidobacterial Succession and Correlation Networks in a Large Unselected Cohort of Mothers and Their Children

Avershina

Storrø

Øien

et al. 2013

Appl Environ Microbiol

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c Bifidobacteria are a major microbial component of infant gut microbiota, which is believed to promote health benefits for the host and stimulate maturation of the immune system. Despite their perceived importance, very little is known about the natural development of and possible correlations between bifidobacteria in human populations. To address this knowledge gap, we analyzed stool samples from a randomly selected healthy cohort of 87 infants and their mothers with >90% of vaginal delivery and nearly 100% breast-feeding at 4 months. Fecal material was sampled during pregnancy, at 3 and 10 days, at 4 months, and at 1 and 2 years after birth. Stool samples were predicted to be rich in the species Bifidobacterium adolescentis, B. bifidum, B. dentium, B. breve, and B. longum. Due to high variation, we did not identify a clear age-related structure at the individual level. Within the population as a whole, however, there were clear age-related successions. Negative correlations between the B. longum group and B. adolescentis were detected in adults and in 1-and 2-year-old children, whereas negative correlations between B. longum and B. breve were characteristic for newborns and 4-month-old infants. The highly structured age-related development of and correlation networks between bifidobacterial species during the first 2 years of life mirrors their different or competing nutritional requirements, which in turn may be associated with specific biological functions in the development of healthy gut.

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“…NA, not applicable. (17). In both cases, the number of suggested components, which is defined based on the drop in eigenvalue, is used as the initial number of components i for MCR-ALS.…”

Section: Figmentioning

confidence: 99%

Bifidobacterial Succession and Correlation Networks in a Large Unselected Cohort of Mothers and Their Children

Avershina

Storrø

Øien

et al. 2013

Appl Environ Microbiol

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“…25,29,31,[36][37][38][39][40][41] It has also been exploited in many kinds of spectroscopy, high performance liquid chromatography, 42,43 gas chromatograph/mass spectrometry, 44 UV-VIS, 45 near-infrared, 46,47 FT-IR, 48,49 fluorescence imaging, 50 etc. In the MCR method, the experimental data is approximated by a linear combination of several spectral components.…”

Section: Introductionmentioning

confidence: 99%

Molecular component distribution imaging of living cells by multivariate curve resolution analysis of space-resolved Raman spectra

Ando

Hamaguchi

2013

J. Biomed. Opt

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Abstract. Label-free Raman microspectroscopy combined with a multivariate curve resolution (MCR) analysis can be a powerful tool for studying a wide range of biomedical molecular systems. The MCR with the alternating least squares (MCR-ALS) technique, which retrieves the pure component spectra from complicatedly overlapped spectra, has been successfully applied to in vivo and molecular-level analysis of living cells. The principles of the MCR-ALS analysis are reviewed with a model system of titanium oxide crystal polymorphs, followed by two examples of in vivo Raman imaging studies of living yeast cells, fission yeast, and budding yeast. Due to the non-negative matrix factorization algorithm used in the MCR-ALS analysis, the spectral information derived from this technique is just ready for physical and/or chemical interpretations. The corresponding concentration profiles provide the molecular component distribution images (MCDIs) that are vitally important for elucidating life at the molecular level, as stated by Schroedinger in his famous book, "What is life?" Without any a priori knowledge about spectral profiles, timeand space-resolved Raman measurements of a dividing fission yeast cell with the MCR-ALS elucidate the dynamic changes of major cellular components (lipids, proteins, and polysaccharides) during the cell cycle. The MCR-ALS technique also resolves broadly overlapped OH stretch Raman bands of water, clearly indicating the existence of organelle-specific water structures in a living budding yeast cell.

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“…We call this method STOCSY-CA, where CA stands for component analysis. It is related to the SIMPLISMA method (simple interactive self-modeling multivariate analysis) used in multivariate curve resolution [14,15], but this relatively simple extension of the STOCSY methodology does not seem to have been described earlier. Since the selected variables have only a positive correlation to each other, the scores should be directly correlated to the concentration when applied to NMR data.…”

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confidence: 99%

Extraction of Alkaloids for NMR-Based Profiling: Exploratory Analysis of an Archaic Cinchona Bark Collection

2012

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Introduction !The crude drug cinchona (Cinchonae cortex) used against malaria is known since the colonization of South America in the beginning of the 17th century. The antimalarial effect is mainly due to the content of quinine (1), which interferes with the development of the Plasmodium parasites in the red blood cells [1]. Cinchona also contains the likewise active analogue alkaloids quinidine (2), cinchonine (3), and cinchonidine (4) (l " Fig. 1) [1][2][3]. The most abundant alkaloid is quinine that accounts for 70-90 % of the total alkaloid content which can be as high as 25 % of the dry weight [4]. Even though there are effective artemisinin-based combination therapies against malaria, there is still an interest in using the bark of Cinchona species (Rubiaceae) for reasons of availability and evolved malaria drug resistance [5,6]. As a result of the economical values of cinchona during the 19th century, plantations were spread to different tropical regions such as Indonesia and India. Different species and hybrids were tested for production of the drug in order to maximize the yield of quinine. During this period, samples of Cinchonae cortex were collected from different parts of the world and eventually ended up in a collection hosted by the Museum of Natural Medicine at the University of Copenhagen. A profiling study of this archaic collection, focused on alkaloids, could possibly indicate species that were not selected due to the quinine content but to other types of antimalarial alkaloids. Since the samples are collected over a long time period, from many different sites, and for many different reasons, we expect a large variation of types and amounts of alkaloids. Profiling of extracted alkaloids might indicate odd samples that contain other types of alkaloids than the expected and so allows finding out about the possible variations and combinations of the known and major alkaloids. NMR is a rational choice of analytical platform for this study. It is rapid, robust and gives reproducible results [7,8]. NMR also gives different spectra of diastereomers, and this makes it possible to differentiate between the main alkaloids. However, the traditional liquid-liquid extraction to separate alkaloids based on their basic properties is not practical for a profiling study in terms of sample throughput and potential problems with robustness. In this study, we present the use of a direct Abstract ! A museum collection of Cinchonae cortex samples (n = 117), from the period 1850-1950, was extracted with a mixture of chloroform-d 1 , methanol-d 4 , water-d 2 , and perchloric acid in the ratios 5 : 5 : 1 : 1. The extracts were directly analyzed using 1 H NMR spectroscopy (600 MHz) and the spectra evaluated using principal component analysis (PCA) and total statistical correlation spectroscopy (STOCSY). A new method called STOCSY-CA, where CA stands for component analysis, is described, and an analysis using this method is presented. It was found that the samples had a rather homogenous content of the well-known cinc...

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Multivariate curve resolution–alternating least squares (MCR-ALS) applied to spectroscopic data from monitoring chemical reactions processes

Cited by 229 publications

References 103 publications

Bifidobacterial Succession and Correlation Networks in a Large Unselected Cohort of Mothers and Their Children

Bifidobacterial Succession and Correlation Networks in a Large Unselected Cohort of Mothers and Their Children

Molecular component distribution imaging of living cells by multivariate curve resolution analysis of space-resolved Raman spectra

Extraction of Alkaloids for NMR-Based Profiling: Exploratory Analysis of an Archaic Cinchona Bark Collection

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