Parvularcula maris sp. nov., an algicidal bacterium isolated from seawater.

A taxonomic study was carried out on strain BGMRC 0090T, which was isolated from seawater. The isolate was a Gram-negative, aerobic, flagellated, rod-shaped bacterium with algicidal activity. Optimal growth was observed at 30 °C, pH 6.0 and with 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BGMRC 0090T belonged to the genus Parvularcula, with highest sequence similarity to Parvularcula lutaonensis CC-MMS-1T (98.4 %). Average nucleotide identity, amino acid identity and digital DNA-DNA hybridization values between strain BGMRC 0090T and five strains of the genus Parvularcula with publicly available genomes were below 84.0, 69.2 and 21.4 %, respectively. The genome of strain BGMRC 0090T was 3.2 Mb with 64.8 mol% DNA G+C content and encoded 2905 predicted proteins, three rRNA, 42 tRNA and four ncRNA genes. Some algicidal biosynthesis-associated genes were detected in the genome. Strain BGMRC 0090T contained Q-10 as the major quinone. The predominant fatty acids were identified as summed feature 8 (C18 : 1ω7c/ω6c) and C16 : 0. Based on the polyphasic evidence presented in this paper, strain BGMRC 0090T is concluded to represent a novel species of the genus Parvularcula, for which the name Parvularcula maris sp. nov. is proposed. The type strain is BGMRC 0090T (= KCTC 92591T=MCCC 1K08100T).

Allorhizobium sonneratiae sp. nov., an endophytic bacterium isolated from the root of Sonneratia apetala.

A novel endophytic bacterium, designated strain BGMRC 0089T, was isolated from a surface-sterilized root of Sonneratia apetala. Cells were observed to be Gram-negative, rod-shaped and motile with polar flagella. Strain BGMRC 0089T was found to grow optimally at 28-30 °C, pH 7.0-8.0 and in the presence of 1 % (w/v) NaCl. Strain BGMRC 0089T contained ubiquinone Q-10 and the predominant fatty acid was summed feature 8. The polar lipid profile of strain BGMRC 0089T was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidylethanolamine. Based on the results of 16S rRNA gene analysis, this isolate has the closest phylogenetic relationships with Rhizobium lemnae L6-16T (96.5 %) and Allorhizobium oryziradicis N19T (96.4 %). Average nucleotide identity, amino acid identity and digital DNA-DNA hybridization values of the isolate with the type strains of the genera Rhizobium and Allorhizobium were below 84.6, 73.9 and 22.1  %, respectively. Analysis the 4.55 Mb draft genome of strain BGMRC 0089T revealed several plant-associated genes, which may play important roles for the plant in the adaptation to the mangrove habitat. Based on its distinct phylogenetic, phenotypic and chemotaxonomic characteristics, strain BGMRC 0089T is proposed to represent a novel Allorhizobium species, for which the name Allorhizobium sonneratiae sp. nov. is proposed (type strain BGMRC 0089T=DSM 100171T=MCCC 1K04805T).

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles.

BACKGROUND: Malaria and neglected communicable protozoa parasitic diseases, such as leishmaniasis, and trypanosomiasis, are among the otherwise called diseases for neglected communities, which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa, Asia, and the Americas. Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period, which have encouraged resistance. These have prompted many researchers to focus on finding new drugs that are safe, effective, and affordable from marine environments. The aim of this review was to show the diversity, structural scaffolds, in-vitro or in-vivo efficacy, and recent progress made in the discovery/isolation of marine natural products (MNPs) with potent bioactivity against malaria, leishmaniasis, and trypanosomiasis. MAIN TEXT: We searched PubMed and Google scholar using Boolean Operators (AND, OR, and NOT) and the combination of related terms for articles on marine natural products (MNPs) discovery published only in English language from January 2016 to June 2020. Twenty nine articles reported the isolation, identification and antiparasitic activity of the isolated compounds from marine environment. A total of 125 compounds were reported to have been isolated, out of which 45 were newly isolated compounds. These compounds were all isolated from bacteria, a fungus, sponges, algae, a bryozoan, cnidarians and soft corals. In recent years, great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds. Comparably, some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs. However, very few of these MNPs have a pharmaceutical destiny due to lack of the following: sustainable production of the bioactive compounds, standard efficient screening methods, knowledge of the mechanism of action, partnerships between researchers and pharmaceutical industries. CONCLUSIONS: It is crystal clear that marine organisms are a rich source of antiparasitic compounds, such as alkaloids, terpenoids, peptides, polyketides, terpene, coumarins, steroids, fatty acid derivatives, and lactones. The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases.

Discrimination of Single Living Rat Pancreatic α, ß, δ, and Pancreatic Polypeptide (PP) Cells Using Raman Spectroscopy.

Primary pancreatic α, ß, δ, and pancreatic polypeptide (PP) cells are reliable cell models for diabetes research. However, the separation and purification of these cells in living conditions remains an obstacle for researchers. The interaction of visible light with cellular molecules can produce Raman scattering, which can be analyzed to obtain cellular intrinsic molecular fingerprints. It has been speculated that primary pancreatic α, ß, δ, and PP cells can be identified and separated from each other according to their spectral differences. To test this hypothesis, Raman spectra detection was performed on rat islet cells. Single islet cells identified by Raman scattering under living conditions were verified using immunohistochemistry. Thus, Raman data were acquired from a pure line of islet cells as a training sample and then used to establish the discriminant function. Then, using the principal component analysis-linear discriminate analysis (PCA-LDA) method, the four types of islet cells could be identified and discriminated by Raman spectroscopy. This study provides a label-free and noninvasive method for discriminating islet cell types in a randomly distributed mixed islet cell population via their physical properties rather than by using antibodies or fluorescence labeling.

Real-Time, Label-Free Detection of Local Exocytosis Outside Pancreatic ß Cells Using Laser Tweezers Raman Spectroscopy.

The examination of insulin (Ins) exocytosis at the single-cell level by conventional methods, such as electrophysiological approaches, total internal reflection imaging, and two-photon imaging technology, often requires an invasive microelectrode puncture or label. In this study, high concentrations of glucose and potassium chloride were used to stimulate ß cell Ins exocytosis, while low concentrations of glucose and calcium channel blockers served as the blank and negative control, respectively. Laser tweezers Raman spectroscopy (LTRS) was used to capture the possible Raman scattering signal from a local zone outside of the cell edge. The results show that the frequencies of the strong signals from the local zones outside the cellular edge in the stimulated groups are greater than those of the control. The Raman spectra from the cellular edge, Ins and cell membrane were compared. Thus, local Ins exocytosis activity outside pancreatic ß cells might be observed indirectly using LTRS, a non-invasive optical method.

[Apoptosis of hepatocellular induced by active ingredients of Zanthoxyli Radix by Raman spectroscopy].

The apoptosis of mono-hepatocellular induced by the active ingredients of the Zanthoxyli Radix was investigated using laser Raman spectroscopy. Hepatoma cells (BEL-7404) were treated with 10 mg•L⁻¹ nitidine chloride and 3 g•L⁻¹ the extracts of Zanthoxyli Radix, respectively, then were divided into two parts, one for fluorescence staining, the other for determination of Raman spectroscopy. The acquired spectra were then processed by background elimination, smoothing, and normalization. Fluorescence staining results showed that the nucleuses from untreated group were uniformly stained, while those from the group treated for 48 hours were densely stained and broken. The spectra results revealed that the intensity of peaks associated with nucleic acid and protein decreased after the cells were incubated with the extracts of Zanthoxyli Radix for 12, 24, 36 and 48 hours. The intensity of peaks at 785,1 002,1 175,1 660 cm⁻¹ was decreased with the time of the cells were incubated by the extracts of Zanthoxyli Radix. The results indicated that the extracts of Zanthoxyli Radix could induce the apoptosis of hepatoma cells and reduce the amount of nucleic acid and protein in the cells. There is a certain relevance between the drug treatment time and the efficacy. The above results suggest that Raman spectra can provide abundant information about the changes in biological macromolecules within the cells after incubated by the extracts of Zanthoxyli Radix and serve as an effective method for the real time measurement of apoptosis.

[A Modified Procedure to Isolate Synchronous Cells from Yeasts with Continuous Percoll Density Gradient and Their Raman Discrimination].

A modified procedure of Percoll density gradient centrifugation was developed to isolate and fractionate synchronous cells from stationary phase (sp) cultures of different yeast strains, as well as Raman spectra discrimination of single yeast cells was reported. About 1.75 mL Percoll solution in 2 mL polypropylene centrifugal tube was centrifuged at 19,320 g, 20 °C with an angle rotor for 15 min to form continuous densities gradient (1.00~1.31 g · mL(-1)), approximately 100 µL sample was overlaid onto the preformed continuous density gradient carefully, subsequently, centrifuged at 400 g for 60 min in a tabletop centrifuge equipped with a angle rotor at 25 °C. Yeast samples could be observed that the suspensions were separated into two cell fractions obviously. Both fractions of different yeast strains were respectively determined by differential interference contrast (DIC), phase contrast microscope and synchronous culture to distinguish their morphological and growth trait. The results showed that the lower fraction cells were unbudded, mostly unicellular, highly refractive, homogeneous and uniform in size, and represented growth characteristic synchronously; Their protoplasm had relatively high density, and contained significant concentrations of glycogen; all of which were accordant with description of quiescent yeast cells and G0 cells in previously published paper. It was shown that lower fraction was quiescent cells, synchronous G0 cells as well. A Raman tweezers setup was used to investigate the differences between two fractions, G0 cells and non G0 cells, at a single cell level. The result showed that both G0 cells and the non G0 cells had the same characteristic peaks corresponding biological macromolecules including proteins, carbohydrates and nucleic acids, but all characteristic peak intensities of G0 cells were higher than that of non G0 cells, implied that the macromolecular substance content of G0 cells was more higher. Principal component analysis (PCA) was performed between G0 cells and non G0 cells, the results showed that the chemical composition content among the synchronization G0 cells has less difference, and G0 cells were homogeneous but non G0 cells were heterogeneous, indicating single cell optical tweezers Raman spectroscopy could identify the synchronous and asynchronous cells. The modified method is feasible, economical and efficient highly. G0 synchronous cells of most yeast strains could be isolated by a modification of Percoll density gradient centrifugation.

[Raman spectra of endospores of Bacillus subtilis by alkali stress].

To research the lethal mechanism of spores stressed by alkali, laser tweezers Raman spectroscopy (LTRS) combined with principal components analysis (PCA) was used to study the physiological process of single spore with alkali stress. The results showed that both spores and germinated spores had tolerance with alkali in a certain range, but the ability of spores was obviously lower than that of spores due to the release of their Ca2+ -DPA which plays a key role in spores resistance as well as spores resistance to many stresses; A small amount of Ca2+ -DPA of spores was observed to release after alkali stress, however, the behavior of release was different with the normal Ca2+ -DPA release behavior induced by L-alanine; The data before and after alkali stress of the spores and g. spores with PCA reflected that alkali mainly injured the membrane of spores, and alkali could be easily enter into the inner structure of spores to damage the structure of protein backbone and injure the nucleic acid of spores. We show that the alkali could result in the small amount of Ca2+ -DPA released by destroying the member channel of spores.

[Physiological differences between HPS/PHI over-expressing transgenic and wild-type geraniums under formaldehyde stress revealed by FTIR analysis].

In the present study, FTIR was used to analyze changes in chemical component contents and spectra characters of 3-hexulose-6-phosphate synthase/6-phosphate-3-hexuloisomerase (HPS/PHI) over-expressing transgenic and wild-type (WT) geraniums under formaldehyde (HCHO) stress to examine if FTIR could be a new method for identification of phenotypic differences between the transgenic plants with a photosynthetic HCHO-assimilation pathway and the WT plants. The WT and transgenic geranium plants were treated with 4 mmol x L(-1) HCHO for 0, 1, 2, 3 and 4 days, respectively. The comparison of FTIR spectral characteristics at different time points between the transgenic and WT plants indicated that the contents of carbohydrate, proteins and aliphatic compounds were significantly higher than those in the WT plants after 4 days of HCHO-treatment. This may be due to installation of the photosynthetic HCHO-assimilation pathway in the transgenic geranium, which enhanced its ability to metabolize and assimilate HCHO, thus allowed more HCHO to be fixed to 6-phosphate fructose, and then entered assimilation pathways for synthesis of a variety of intracellular components. The results suggest that FTIR can be a new method to identify the phenotypic differences between transgenic plants with a photosynthetic HCHO-assimilation pathway and WT plants.

[Calibration methods of infrared spectra for geographical origins determination of Radix Zanthoxyli].

The instrument and the experimental environment influence the infrared spectra, which may limited the identification of the samples by a prediction model. Based on the Fourier transform infrared spectroscopy (FTIR) technology, the authors performed different infrared spectral calibration methods for Radix Zanthoxyli geographical origins determination, the SIMCA was used to establish an identification models, and the model was used to distinguish samples from four different regions of Guangxi. According to the result of prediction, the authors could obtain the most suitable calibration method for the identification model. The results showed that, respectively, by the multiple scattering correction and standard normal variation, their PCA data distribution and the distance between models is ideal, suggesting that we can eliminate the interference from the environmental and human factors by these two correction methods, and also separate each samples of different habitats. The test using the method to measure the geographical origins of Radix Zanthoxyli proved that the recognition rate and rejection rate are both at or near 100%. Visible, and both the multiplicative scatter correction and the standard normal variation are all the ideal calibration methods for Radix Zanthoxyli infrared spectral geographical origins determination.

[Study on Camellia Sect. Chrysantha Chang species identification by FTIR technology].

FTIR spectra from 16 kinds of Camellia Sect. Chrysantha by Fourier transform infrared spectroscopy (FTIR) method combined with the system clustering and correlation coefficient method were used to analyze and compare these spectral data. The results, show that: Camellia Sect. Chrysantha of 16 kinds were divided into three groups, the first kind was: C. longzhouensis etc, in all eleven kinds; The second kind was: C. achrysantha, C. limonia, C. pingguoensis and C. chuongtsoensis; The third kind was C. microcarpa, which for a class alone. According to the difference in related anatomy and morphology, this study supported that C. longgangensis and C. ptilosperma should be incorporated into one kind; C. multipetala, C. longgangensis, C. parvipetala, C. tunghinensis and C. limonia, C. achrysantha, C. microcarpa, C. nitidissima, C. terminali and C. pingguoensis should be divided into separate species. FTIR-cluster analysis can be used as a possible means for the identification of Camellia Sect. Chrysantha.

[Analysis and evaluation of taxol contents in different parts between Taxus media and Taxus mairei based on Fourier transform infrared spectroscopy].

In the present study, combined with external standard method, second derivative as well as curve-fitting equation, the infrared spectroscopy techniques were applied to research the discrepancy of paclitaxel content among different parts of them repectively as well as the differences of infrared spectral character between Taxus Media (T. Media) and Taxus Mairei (T. Mairei). The results showed: (1) The band around 1516, 1371, 1 244, 1109 and 773 cm(-1) was markedly enhanced when paclitaxel standard sample was added by more than 0. 004 5 mg to original traditional Chinese materials, in addition, in infrared fingerprint area, the second derivative spectra show that there was good corresponding peak between traditional Chinese materials and standard paclitaxel sample around 1371, 1315, 1244, 1143, 1106, 1070, 1022 and 773 cm(-1), furthermore, the intensity of above character band would increase accompanying with increased standard paclitaxel sample. So, the band character around 1371, 1315, 1244, 1143, 1106, 1070, 1022 and 773 cm(-1) could be used to evaluate paclitaxel content of T. media and T. mairei; (2) Around 1800-700 cm(-1), IR spectral features suggest that two kinds of Chinese yew had quite similar infrared vibration character, but when Gaussian function was applied to decompose the band around 1058 cm(-1), the result demonstrated that the T. media were decomposed with 8 while T. mairei were only decomposed with 7 component bands. (3) Second-derivative and curve-fitting equation analysis demonstrated that there were certain differences of paclitaxel content between T. media and T. mairei as well as different parts of them. Specifically, the paclitaxel content of T. media was higher than T. mairei, while the paclitaxel content in leaf of T. media was highest, on the contrary, the paclitaxel content in root of T. mairei was highest when comparing the content among the different parts of T. media and T. mairei respectively. Therefore, above methods could be quickly analyze and evaluate the differences of paclitaxel content between T. media and T. mairei as well as the different parts of them.

[Raman spectra and structure analysis of 2,6-pyridine dicarboxylic acid in different states and single Bacillus spore].

The Raman spectra of 2,6-pyridine dicarboxylic acid (DPA) and their calcium salts(Ca-DPA) in different states and the Ca-DPA in a single bacterial spore have been recorded by laser tweezers Raman system (LTRS) and the spectra have been assigned. Raman spectra of different states of DPA and Ca-DPA are different evidently. Analysis leading to differences in the structure of spectrum may be due to that the Raman spectra of DPA crystalline reflected more precise characteristics information compared to DPA powder, in which the laser can penetrate through DPA crystalline and the Raman scatter from the crystalline interior is greater than that from DPA powder. The second reason is that DPA powder and Ca-DPA crystalline contain water molecules, and the intermolecular hydrogen bonding in the crystals of these molecules is extensive. The presence of calcium ions would affect the pyridine ring so that both sides of the carboxyl pyridine ring have a certain geometric deformation and the hydroxy carboxylic was damaged. The DPA2-anion is principal in Ca-DPA and the DPA solution. The calcium ion affects the stability of the pyridine ring structure in the Ca-DPA solution. The result from the spectra also showed that the DPA in single spores present Ca-DPA crystal state.

[Analysis of components difference of yeast strains based on laser tweezers Raman spectroscopy combined with multistatistical analysis].

The combination of laser tweezers and con-focusing Raman spectroscopy (LTRS) has made it possible to investigate single cells in aqueous media. In our experiments, a modified method of Percoll density gradient centrifugation was developed for isolating synchronous cells from six yeast strains and Raman spectra of single yeast cells were collected by LTRS as well, in which multiple statistical analysis, principal component analyses (PCA) and discriminant function analysis (DFA) were applied to distinguish synchronous cells between yeast strains statistically. The result showed that Raman spectra scattered from the trapping yeast cells could provide intrinsic molecular information, and there were remarkable difference among those of six yeast strains in Raman spectrogram which correspond to various biomacromolecule, the difference of protein as well as lipid were significantly higher than nucleinic acid between two of yeast strains randomly, and among the six strains, synchronized yeast cells can be discriminated using PCA and DFA based on 14 most contribution bands, 706, 862, 918, 997, 1 073, 1 127, 1 269, 1 291, 1 305, 1 429, 1 465, 1 591, 1 602 and 1 652 cm(-1), 10 bands of which were from protein, 3 bands were from lipoid, and 1 band was from nucleinic acid. To validate their significance, these variables were used to reperform DFA analysis and the replotted PC-DFA was the same as in the previous PC-DFA analysis, and the data would be considered validated. The authors show that the approach of laser tweezers Raman spectroscopy combined with multistatistical analysis has the potential to study difference among yeast strains.

[Application of two FTIR pattern recognition methods to the Zanthoxylum nitidum geographical origins determination].

In the present work, the authors explored a rapid method of the Zanthoxylum nitidum geographical origins determination. Based on Fourier transform infrared spectroscopy (FTIR) technology, the band of 1 800-400 cm(-1) which is the IR fingerprint of Zanthoxylum nitidum, the Fisher ratio and the soft independent modeling of class analogies (SIMCA) were used to build a classification model. Respectively, four kinds of Zanthoxylum nitidum in the Guangxi region were detected by the model, and the model was verified by calculating their recognition rate and rejection rate. The results show that the authors can accurately extract the overall information of Chinese herbal medicines by using the FTIR, also established a pattern recognition model to predict unknown samples, and obtained satisfactory recognition rate and rejection rate, indicating that the model has stronger ability of identification. The detection on real time was carried out rapidly with the Fisher model, suggesting that the model has more practical value.

[Probing the mechanism and Ca-DPA concentration of individual Bacillus spores using trapping and Raman spectroscopy].

Measuring the levels of 2,6-pyridine dicarboxylic acid (DPA) in bacteria spores could provide the information about the DPA function, resistance mechanism and the mechanism of spore germination. The authors have measured levels of Ca-DPA of individual spores of different 19 kinds of Bacillus which from different sources, species, and strains by using laser tweezers Raman spectroscopy (LTRS). Also we have verified the reproducibility of the system simultaneously. To investigate the biochemical components and structure in single spore, a Raman tweezers setup was used to record the Raman spectrum of single spore. A NIR laser beam (30 mW, 785 nm) was introduced into an inverted microscope to form a tweezers for trapping the spore suspended in water, and the Raman scatter was excited by the same beam. Raman spectra of 30 spores of 19 bacillus strains which collected from different area in China were recorded, and 100 spores of B. subtilis ACCC10243 were measured. A spore of the same strain was probed 100 times for verifying the reproducibility of the LTRS system. A Matlab 7.0 edited program and Origin 8.0 were used to process the spectral data. Because Ca-DPA is the chelate of DPA and the calcium ion, and the strongest Raman bands at 1 017 cm(-1) was from Ca-DPA component of the spore, its intensity was linearly with the Ca-DPA concentration. Therefore, the 1017 cm(-1) bands of Ca-DPA could be used as the quantitative standard peak, and then calculated the concentration of Ca-DPA could be calculated according the intensity of 1017 cm(-1) peak. The results showed that Raman spectra of single spore can reflect the characteristics information of it. The diversity of Ca-DPA levels not only happened between different species and strains of bacillus, but also happened between different individual spores in the same strains of bacillus. Conclusion from these measurements is that there is heterogeneity in different individual spores. It is convenient to trapping and collecting its Raman spectrum in water directly, and then get the information of the level of DPA, without the complex preparation of separating, purifying spores and abstracting DPA, so we predict LTRS as a high sensitivity, high accuracy, rapid and effective method in the research of individual spores.

[Investigation on the difference in HCHO metabolic mechanism between Arabidopsis and tobacco using FTIR].

In the present study, the model plants, arabidopsis and tobacco, were chosen for FTIR analysis to investigate the spectrum characters and the changes in their chemical component contents in the time course of HCHO treatment, providing clues to explain the difference in HCHO metabolic mechanism between the two plants. The FTIR data showed that all the chemical components of arabidopsis and tobacco varied under HCHO stress conditions. An interested peak near 1,376 cm(-1) which was assigned as the absorption of methyl group of cellulose was specially existed in the spectrum of arabidopsis. This peak showed a mild decrease compared with other peaks at the beginning (at 1 day) of HCHO stress. This indicated that the major part of HCHO metabolic flux was introduced towards its oxidation pathway to form HCOOH and CO2 subsequently and only small amount of HCHO entered the other pathways. The CO2 was assimilated in Calvin cycle to form sugars which might be used to synthesis of cellulose later. At 7 day of HCHO treatment, the height of the peak decreased whereas the height of the other peaks still increased. This might suggest that the gene expression of some enzymes in the HCHO oxidation pathway was inhibited under HCHO stress conditions and the inhibition might not happen to the gene expression of the enzymes in other pathways. In the case of tobacco, the contents of all chemical components showed the same variation on the FTIR spectrum in the time course of HCHO treatment, which indicated that there was no much difference in HCHO metabolism flux in each pathway. At 4 day of HCHO treatment, the decrease in the height of all peaks is the result of the poor ability of HCHO metabolism of tobacco, which also demonstrated the lower HCHO tolerance of tobacco compared with arabidopsis.

[Origins determination of Herba Abri cantoniensis and Herba Abri mollis with FTIR combined with fuzzy cluster and curve-fitting].

The methods of fuzzy cluster and curve-fitting combined with FTIR were used to determine the origins of Herba Abri cantoniensis and Herba Abri mollis. The spectra of Herba Abri cantoniensis and Herba Abri mollis are similar, both with typical spectral shapes. The two spectra can be divided into 3 parts: the 1st is 3 500-2 800 cm(-1), containing stretching bands of -OH, N-H, and CH2 ; the 2nd is 1 800-800 cm(-1), containing stretching bands of ester carbonyl group and indican C-O(H), vibrational bands of C=C and benzene ring; The 3rd is 800-400 cm(-1), containing skeletal vibration and scissoring vibration of molecular. The recorded FTIR spectral data were processed by 9-point-smoothing, 1st derivative, SNV and fuzzy cluster analysis sequentially. The fuzzy cluster analysis was carried out by similarity or dissimilarity matrix, and two matrices are computed with Manhattan and Euclidean distance. The results indicated that the optimization used Manhattan and dissimilarity matrix, and 5 origins of Herba Abri cantoniensis were perfectly discriminated, but 2 origins of Herba Abri mollis were mixed and identified from the other 3 origins. So the characterized bands at 1 034 cm(-1) of the average 1-D spectra of Herba Abri cantoniensis and Herba Abri mollis were fitted combining 2nd derivative for further distinguishing their spectral characteristic. The results of curve-fitting showed that the bands of wild Herba Abri cantoniensis and the other origin ones were decomposed to 11 and 9 component bands respectively, but the bands of Shanglin and the other origins Herba Abri mollis were decomposed to 9 and 8 component bands dissimilarly, and the locations and normalized densities of these component bands were different. From this, together with the results of fuzzy cluster analysis, it is concluded that the combination of two methods may identify the origins of Herba Abri cantoniensis and Herba Abri mollis availably.

[Comparative study on the infrared fingerprint of Abrus cantoniensis based on the methods of sequential analysis of dual-indexes and cluster analysis].

The methods of sequential analysis of dual-indexes and cluster analysis were utilized to investigate the infrared fingerprints of A. cantoniensis planted in different years and different places in Guangxi, China. The results showed that 6 samples were able to be completely separated only through 13 point smoothing, when the dual-indexes analysis was applied in the present research, and the accurate relationship between these samples could be inspected and expressed by quantitative relationships under 6-dimensional spaces; however, the effect of cluster was bad only through 13 point smoothing of raw spectra, and it was very difficult to find out the regular sequences while the cluster analysis was applied. Furthermore, the 6 samples were able to be completely separated if raw spectra were dealed with 1st derivative after 13 point smoothing, and the clustering effects were more obvious and 6 samples of A. cantoniensis were completely separated. The above two methods could be used to evaluate the quality of Chinese medicinal materials easily when the sample was not excessive quantitatively, but the method of dual-indexes analysis was more difficult than the clustering analysis if the sample size was too large, since a mass of data such as common peak ratio and variation peak ratio of the IR fingerprint spectra were processed and analyzed statistically, while this method could accurately find out the closest relationship between any samples through comparing the quantitative relationships of common peak ratio and variation peak ratio of each sample under 6-dimensional space; the precision of cluster analysis was less than dual-indexes analysis, but it was more convenient than dual-indexes analysis when large sample data were analysed. Finally the above two methods all showed that the chemical composition of the A. cantoniensis was similar in the same cultivated area, but the difference in chemical composition of A. cantoniensis in different years was distinct even they were in the same place.

Real-time detection of single-living pancreatic beta-cell by laser tweezers Raman spectroscopy: high glucose stimulation.

Glucose acts as a beta-cell stimulus factor and leads to cellular responses that involve a large amount of biomolecule formation, relocation, and transformation. We hypothesize that information about these changes can be obtained in real-time by laser tweezers Raman spectroscopy. To test this hypothesis, repeated measurements designs in accordance with the application of Raman spectroscopy detection were used in the current experiment. Single rat beta-cells were measured by Raman spectroscopy in 2.8 mmol/l glucose culture medium as a basal condition. After stimulation with high glucose (20 mmol/l), the same cells were measured continuously. Each cell was monitored over a total time span of 25 min, in 5 min intervals. During this period of time, cells were maintained at an appropriate temperature controlled by an automatic heater, to provide near-physiological conditions. It was found that some significant spectral changes induced by glucose were taking place during the stimulation time course. The most noticeable changes were the increase of spectral intensity at the 1002, 1085, 1445, and 1655 cm(-1) peaks, mainly corresponding to protein and lipid. We speculate that these changes might have to do with beta-cell protein and lipid synthesis. Using laser tweezers Raman spectroscopy in combination with glucose stimulation, optical spectral information from rat beta-cells was received and analyzed.