Major Pigment Research Articles

Cross-front phytoplankton pigments and chemotaxonomic groups in the Indian sector of the Southern Ocean

This work describes the phytoplankton pigments and main taxonomic groups across major oceanographic fronts in the Indian Sector of the Southern Ocean. Seawater samples were collected in late summer of 2011, during an Indian Southern Ocean Expedition. Twenty five stations were occupied by RV Sagar Nidhi along two longitudinal transects (between 37°S and 60°S). High Performance Liquid Chromatography (HPLC) analysis was performed to identify and quantify phytoplankton pigments concentration and the CHEMTAX software was applied to determine the relative contribution of the main taxonomic groups to total chlorophyll a (phytoplankton biomass index). Our results showed that the spatial distribution of phytoplankton groups, identified by pigment data, was highly correlated with ocean surface thermal gradients. Subtropical, Subantarctic and Antarctic surface waters were, respectively, mainly associated with (i) prochlorophytes (zeaxanthin and divinyl-chlorophyll a as the major pigments), (ii) haptophytes (19′-butanoyloxyfucoxanthin and 19′-hexanoyloxyfucoxanthin as the major pigments), and (iii) diatoms (fucoxanthin as the major pigment). This study contributes to better understanding the distribution of phytoplankton and its association with physical gradients in an undersampled complex region of the Southern Ocean.

Modified molecular interactions of the pheophytin and plastoquinone electron acceptors in photosystem II of chlorophyll D-containing Acaryochloris marina as revealed by FTIR spectroscopy.

Acaryochloris marina is a unique cyanobacterium that contains chlorophyll (Chl) d as a major pigment. Because Chl d has smaller excitation energy than Chl a used in ordinary photosynthetic organisms, the energetics of the photosystems of A. marina have been the subject of interest. It was previously shown that the redox potentials (E m's) of the redox-active pheophytin a (Pheo) and the primary plastoquinone electron acceptor (QA) in photosystem II (PSII) of A. marina are higher than those in Chl a-containing PSII, to compensate for the smaller excitation energy of Chl d (Allakhverdiev et al., Proc Natl Acad Sci USA 107: 3924-3929, 2010; ibid. 108: 8054-8058, 2011). To clarify the mechanisms of these E m increases, in this study, we have investigated the molecular interactions of Pheo and QA in PSII core complexes from A. marina using Fourier transform infrared (FTIR) spectroscopy. Light-induced FTIR difference spectra upon single reduction of Pheo and QA showed that spectral features in the regions of the keto and ester C=O stretches and the chlorin ring vibrations of Pheo and in the CO/CC stretching region of the Q A (-) semiquinone anion in A. marina are significantly different from those of the corresponding spectra in Chl a-containing cyanobacteria. These observations indicate that the molecular interactions, including the hydrogen bond interactions at the C=O groups, of these cofactors are modified in their binding sites of PSII proteins. From these results, along with the sequence information of the D1 and D2 proteins, it is suggested that A. marina tunes the E m's of Pheo and QA by altering nearby hydrogen bond networks to modify the structures of the binding pockets of these cofactors.

Isolation and expression analysis of four putative structural genes involved in anthocyanin biosynthesis in Begonia semperflorens

SummaryAs the major colour pigments in plants, anthocyanins play a positive photoprotective role in plant resistance to abiotic stress. In this work, variations in anthocyanin concentration were determined in the leaves of Begonia semperflorens growing under high light (HL; 900 ?mol m-2 s-1) or low temperature (LT; 15°C day/6°C night) conditions. Partial cDNA sequences of four structural genes associated with the biosynthesis of anthocyanins were isolated from leaves. These genes encoded phenylalanine ammonia-lyase (BsPAL), chalcone synthase (BsCHS), flavonone-3-hydroxylase (BsF3H), and anthocyanidin synthase (BsANS). The patterns of expression of these genes after HL or LT treatment were investigated using real-time reverse transcription-quantitative PCR (RT-qPCR). Anthocyanins, which remained at low concentrations in untreated leaves, increased significantly after HL or LT treatment.Transcript levels of all four genes corresponded, in general, with these changing patterns, but their expression profiles were significantly different between the HL and LT treatments. After LT treatment, the expression of BsPAL and BsF3H increased significantly in the first 2 d, then decreased, while transcript levels of BsCHS and BsANS increased gradually and reached their maximum level by day-6. During HL treatment, the expression of BsCHS and BsF3H responded almost immediately 0.5 d after treatment, then BsF3H expression decreased sharply to a level only slightly higher than in the untreated controls. However, expression of BsCHS remained at high levels. Expression of BsANS increased sharply 1 d after HL treatment, then decreased until day-4. Transcription of BsPAL increased rapidly 2 d after treatment, then decreased rapidly. Understanding the different regulatory mechanisms of anthocyanin biosynthesis under HL or LT stress would improve our understanding of the genetic and physiological mechanisms of adaption of B. semperflorens to abiotic stresses.

Curcumin inhibits aerobic glycolysis and induces mitochondrial-mediated apoptosis through hexokinase II in human colorectal cancer cells in vitro.

Curcumin, the major pigment of the dietary spice turmeric, has the potential for chemoprevention by promotion of apoptosis. Here, we investigated the molecular mechanisms of curcumin in glycolytic inhibition and apoptotic induction in human colorectal cancer HCT116 and HT29 cells. On the one hand, curcumin downregulated the expression and activity of hexokinase II (HKII) in HCT116 and HT29 cells in a concentration-dependent manner, but had little effect on the other key glycolytic enzymes (PFK, PGM, and LDH). On the other, curcumin induced dissociation of HKII from the mitochondria, resulting in mitochondrial-mediated apoptosis. Furthermore, the phosphorylation of mitochondrial HKII through AKT was responsible for the curcumin-induced dissociation of HKII, which was different from the mechanism of HKII inhibitor 3-BrPA. These results have important implications for the metabolism reprogramming effect and the susceptibility to curcumin-induced mitochondrial cytotoxicity through the regulation of HKII, and provide a molecular basis for the development of naturally compounds as novel anticancer agents for colorectal carcinoma.

황금찰수수 도정부산물의 항산화 및 항염증 활성

유색 수수인 황금찰수수를 도정할 때 grain과 함께 발생하는 도정부산물인 hull과 bran의 4가지 용매 추출물의 총 폴리페놀 함량, 항산화 활성, 천연색소 함량과 RAW 264.7 세포주를 이용하여 항염증 활성을 검정하였으며 결과를 요약하면 아래와 같다. 1. 도정부산물인 hull의 100% 메탄올과 70% 에탄올 추출물에서 총 폴리페놀 함량이 <TEX>$29.4{\pm}0.4$</TEX>와 <TEX>$29.7{\pm}0.2mg\;GAE/100g$</TEX>으로 가장 많았고, ABTS 라디컬 소거능(<TEX>$IC_{50}$</TEX>)이 <TEX>$6.8{\pm}0.4$</TEX>, <TEX>$6.3{\pm}0.1{\mu}g/mL$</TEX>로 가장 높은 항산화 활성을 나타내었다. 2. 총 천연색소 함량에서도 수수 hull의 0.5% 염산 함유 100% 메탄올 추출물에서 <TEX>$322.6{\pm}14.5mg/100g$</TEX>으로 가장 많은 색소 함량을 나타내었고 hull, bran, grain 모두의 경우에서 0.5% 염산을 함유한 100% 메탄올을 용매로 추출한 경우에서 가장 많아 수수를 이용하여 천연색소를 추출할 경우 수수 부산물인 hull을 산을 함유한 메탄올로 추출하였을 때 가장 많은 색소 추출물을 얻을 수 있었다. 3. 수수 도정부산물과 grain 추출물을 LPS로 NO 생성을 유도한 RAW 264.7 세포에 처리하였을 때, 세포 독성이 없는 100 ug/mL 농도 이하에서의 NO 생성 억제량은 hull, bran, grain 추출물의 순으로 나타났고 hull 추출물의 경우에 농도에 따라 가장 큰 NO 생성 억제를 보였으며 천연색소 화합물 중에서는 apigeninidin의 NO 생성 억제 활성을 확인하였다. 4. 위 결과를 종합해 볼 때, 수수 도정부산물 중 hull은 grain에 비해 총 폴리페놀 화합물과 천연색소 함량이 높고 항산화 활성과 RAW 264.7 대식세포에서의 NO 생성량 억제 활성이 우수하여 앞으로 수수 부산물이 항산화 및 항염증 소재로 가능성이 있음을 확인하였다. Sorghum has been consumed as one of the important staple food in the semiarid tropics of Africa and Asia. Sorghum is rich in starch, protein, essential vitamins and minerals and grows relatively well in dry climate regions when it compared with other staple food crops. Sorghum has taken an increased interest due to several studies that report about the beneficial effects of sorghum on human health. In the present study, we investigated the antioxidative and activity of extract of milling by-products (hull and bran) of Korean sorghum cultivar, 'Hwanggeaumchal' as well as its grain. Hull extract showed the highest total polyphenol contents (<TEX>$29.7{\pm}0.2mg\;GAE/100g$</TEX>) and major four pigments content (<TEX>$322.6{\pm}14.5mg/100g$</TEX>). From results of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging activity, hull extract (<TEX>$IC_{50}$</TEX>, <TEX>$6.3{\pm}0.1{\mu}g/mL$</TEX>) was also showed the strongest antioxidative effects. Bran and grain showed similar polyphenol, pigments contents and antioxidative effects. We determined cell viability by MTT assay and evaluated the anti-inflammatory activity by measuring nitric oxide (NO) of hull, bran and grain methanol extract (0.5% HCl v/v) on RAW 264.7 cells. Hull extract treatment was significantly decreased NO production with dose-dependant manner. Apigeninidin as one of the major pigment of hull was showed inhibitory activity against NO production without cytotoxicitiy. Therefore, sorghum milling by-products can be used as a good source of antioxidative and anti-inflammatory agents.

Soy β-Conglycinin−Curcumin Nanocomplexes for Enrichment of Clear Beverages

Delivery of sensitive health-promoting compounds in foods and beverages is an important and timely challenge. Curcumin, a natural polyphenol and the major pigment of the turmeric root, is a potent antioxidant with numerous attributed health benefits. However the major hurdle for applicability of curcumin as a food ingredient is its extremely low solubility in aqueous solutions at both acidic and neutral pH, and its consequent poor bioavailability. Here we have studied the possibility of using the soybean protein β-conglycinin (β-Cg) to form co-assembled nanovehicles for delivery of curcumin in clear beverages, where dietary and religious constraints preclude the use of milk proteins. Using visible light spectrophotometry we found high affinity between β-Cg and curcumin with a binding constant of about 1.27 · 106 M−1. The curcumin − β-Cg co-assemblies were much smaller than the curcumin aggregates without β-Cg. While in the absence of β-Cg, curcumin aggregates were several microns large and visible by eye, in the presence of β-Cg, particles were much smaller and showed a bimodal size distribution, with modal-average diameters of 27 nm (~90 % of the particles on a volume basis) and 110 nm (~10 %), and average of 46 nm, as measured by dynamic light scattering, and supported by cryoTEM images. Therefore, transparency was maintained in the β-Cg-curcumin co-assembly systems, enabling application in clear beverages. The curcumin – β-Cg system was characterized at increasing molar ratios. The binding sites saturation point of β-Cg was found to be around 15:1 curcumin:β-Cg molar ratio, or about 3 g curcumin/100 g β-Cg. Based on light microscopy observations, the presence of β-Cg both suppressed curcumin crystallization and modified crystal morphology. Moreover, β-Cg − curcumin co-assemblies were found to confer considerable protection to curcumin against light and oxidation induced degradation.

Clearing the muddy waters: using lake sediment records to inform agricultural management

Milltown Lake is located in the Irish drumlin belt where small lakes are interspersed amongst rolling hills. Because of poor drainage characteristics of soils in this region, grassland agriculture dominates, with beef rearing and dairying as the main agricultural enterprises. We used paleolimnological techniques in conjunction with export coefficients to investigate the relationship between historical development of eutrophication in the lake and changes in nutrient loading from the watershed. Sediment cores representing the period ~1970 to 2008 were analysed for fossil pigments using high performance liquid chromatography to provide proxies for changes in abundance of the main algal groups. Geochemical variables, including total phosphorus, were also analysed, and nutrient loading was estimated using historical data. Concentrations of all major pigments increased up-core, as did nutrient loading from the watershed, between ~1970 and 2008. Export coefficient estimates showed that, on average, 82.2 % of P loads were attributable to two sources, cattle and grassland. More specifically, the P load from cattle was strongly correlated to overall algal abundance, whereas the P load from people was negatively related to algal abundance indicators. Results also suggested that artificial fertilisers were less important drivers of algal abundance than organic manure from cattle. These results highlight the potential problems associated with farming practices that generate large amounts of organic manure, especially when located on poorly drained and steeply sloping lands. The findings contribute to the management of such small lakes, particularly given the potential conflict between increasing agricultural output and the implementation of the European Union Water Framework Directive on a national scale.

Effects of flashing light-emitting diode (LED) of several colors on the growth of the microalga Isochrysis galbana

The growth rate of Isochrysis galbana was determined under flashing light conditions (104 μmol m-2s-1 light intensity, 10 kHz frequency, and 50% of the duty cycle) of several colors. The most suitable light for the growth of I. galbana was blue (dominant wavelength: 470 nm). After six days, the cell density under blue light was 34.0 × 105 cells mL-1, and was 1.4, 1.6, 1.8,and 2.2 times higher than those under white, red, white non-flashing, and green light, respectively. The peak wavelengths of white and blue lights are nearly consistent with the absorbance maxima of major pigments, which are chlorophylls and xanthophylls, in I. galbana. White and blue light were considered to be most effective for I. galbana growth. Key words: Algal growth, light conditions, light-emitting diode (LED), duty cycles, flash.

Studies on Valuable Pigments from Florets of Safflower (C. tinctorius L.,) and Their Identification by TLC Method

India is the largest producer of safflower in the world with highest acerage. It is one of the humanity;s oldest crop cultivated mainly for oil from the seeds and redissh dye from the flowers. Intrest in this crop has been rekindled in the last few years because of the medicinal importances of the safflower florets . In china it is being grown exclusively for its flower’s as they are usedfor the treatment of many illnesses as well as in the preparation of “Green Tea“. Medicinal importance of the florets are mainly attributedto the presences of two major pigments i.e carthamin and safflower yellow (carthamidin). Most of the work is confined to the Chinese and Iranian Genotypes, there is no systematic report available on the isolation and characteriztion of florets pigments for Indian Genotypes. Therefore, the present study is aimed at isolation and characterization of carthamin and carthamidin (yellow pigment) in the four Indian Genotypes.

Performance of Caesalpinia sappan heartwood extract as photo sensitizer for dye sensitized solar cells

A natural dye extracted from Caesalpinia sappan heartwood was used as photo sensitizer for the first time to fabricate titanium dioxide (TiO2) nanoparticles based dye sensitized solar cells. Brazilin and brazilein are the major pigments present in the natural dye and their optimized molecular structure were calculated using Density functional theory (DFT) at 6-31G (d) level. The HOMO–LUMO were performed to reveal the energy gap using optimized structure. Pure TiO2 nanoparticles in anatase phase were synthesized by sol–gel technique. The pure and natural dye sensitized TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies. Low cost and environment friendly dye sensitized solar cells were fabricated using natural dye sensitized TiO2 based photo anode. The solar light to electron conversion efficiency of Caesalpinia sappan heartwood extract sensitized dye sensitized solar cell is 1.1%.

Influence of composition and roughness on the pigment mapping of paintings using mid-infrared fiberoptics reflectance spectroscopy (mid-IR FORS) and multivariate calibration.

Mid-infrared fiberoptics reflectance spectroscopy (mid-IR FORS) is a very interesting technique for artwork characterization purposes. However, the fact that the spectra obtained are a mixture of surface (specular) and volume (diffuse) reflection is a significant drawback. The physical and chemical features of the artwork surface may produce distortions in the spectra that hinder comparison with reference databases acquired in transmission mode. Several studies attempted to understand the influence of the different variables and propose procedures to improve the interpretation of the spectra. This article is focused on the application of mid-IR FORS and multivariate calibration to the analysis of easel paintings. The objectives are the evaluation of the influence of the surface roughness on the spectra, the influence of the matrix composition for the classification of unknown spectra, and the capability of obtaining pigment composition mappings. A first evaluation of a fast procedure for spectra management and pigment discrimination is discussed. The results demonstrate the capability of multivariate methods, principal component analysis (PCA), and partial least squares discrimination analysis (PLS-DA), to model the distortions of the reflectance spectra and to delimitate and discriminate areas of uniform composition. The roughness of the painting surface is found to be an important factor affecting the shape and relative intensity of the spectra. A mapping of the major pigments of a painting is possible using mid-IR FORS and PLS-DA when the calibration set is a palette that includes the potential pigments present in the artwork mixed with the appropriate binder and that shows the different paint textures.

Two-step process for production of biodiesel blends from oleaginous yeast and microalgae

Biodiesel produced from oleaginous microorganisms shows promise in displacing use of petroleum diesel fuel, however, low biodiesel yields and rigorous processing have thwarted large-scale commercialization. Here, we report a simple and efficient two-step process for generating biodiesel blends from microbial biomass, which eliminates the need for solvent extractions, distillations, or additional purifications. In the present work, diesel fuel was utilized to extract biodiesel produced from direct transesterification of the yeast, Cryptococcus curvatus, and microalgae, Scenedesmus dimorphus, thus generating a blend of microbial biodiesel and diesel fuel. Up to 93% and 83% of the produced biodiesel is extracted from both yeast and microalgae, respectively, whereas the majority of pigments are excluded. A B20 blend produced from yeast meets key ASTM fuel requirements including flash point, viscosity, sulfur, oxidation stability, and acid number. Integration of experimental data into system models reveals a 25% reduction in the net energy ratio (NER) with the process presented here compared to traditional solvent extraction.

High-performance liquid chromatography-diode array detector-mass selective detector analysis of major natural dyes with the application of H2O2/ultraviolet treatment as a way to simulate burial degradation of textiles

H2O2/ultraviolet (UV) radiation treatment was proposed to simulate burial-induced degradation of natural dyes. The method was applied to the major pigments of Phellodendron bark, madder, and indigo plant, and their silk dyeings, and the degraded samples were analyzed using high-performance liquid chromatography-diode array detector-mass selective detector (HPLC-DAD-MS). Retention times of the HPLC chromatogram, UV-visible λmax obtained from DAD analysis, and major ion detected by the MS analysis were used to identify berberine, palmatine, alizarin, purpurin, indigotin, and indirubin included in dye solution and the extraction from silk dyeing. Alizarin, purpurin, and indirubin were more susceptible to degradation by H2O2/UV than berberine and palmatine. Indigotin was completely degraded with 5 minutes of treatment, producing isatin as the degradation product. Alizarin, purpurin, and indigotin were more resistant to degradation when they were affixed to the fibers.

Characterization of halophilic C50 carotenoid-producing archaea isolated from solar saltworks in Bohai Bay, China

Halophilic archaea comprise the majority of microorganisms found in hypersaline environments. C50 carotenoids accumulated in archaea cells are considered potential biotechnological products and possess a number of biological functions. Ten red colonies were isolated from brine water in a saltern crystallizer pond of the Hangu Saltworks, China. 16S rRNA gene sequence analysis showed that the colonies belonged to the extremely halophilic archaea genera Halobacterium and Halorubrum. Two representative strains, Halobacterium strain SP-2 and Halorubrum strain SP-4, were selected for further study on the phenotypic characteristics and effects of salinity and pH on accumulation and composition of pigments in their cells. The archaeal strains were isolated and grown in a culture medium prepared by dissolving yeast extract (10 g/L) and acid-hydrolyzed casein (7.5 g/L) into brine water obtained from a local salt pond. Their optimum salinity and pH for growth were 250 and 7, respectively, although pigment accumulation (OD490 / mL broth) was highest at pH 8. In addition, at 150–300 salinity, increasing salinity resulted in decreasing pigment accumulation. Analysis of the UV-Vis spectrum, TLC and HLPC chromatograms showed that C50 carotenoid bacterioruberin is the major pigment in both strains.

Green grasses as light harvesters in dye sensitized solar cells

Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV–Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography–mass spectrometry (LC–MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC–MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

가자열매 추출물을 이용한 단백질 섬유의 염색과 항균효과

The purpose of this study was to investigate the dyeing properties and anti-microbial ability of silk and wool fabrics dyed with Terminalia chebula Retzius(TCR) extract using two extraction solvent, hot water and methanol. Dyeing properties of fabrics were studied by investigating the characteristics of colorant, changes in dye uptake under different dyeing conditions, and by investigating color change when mordants were applied. Also, color fastness, and antimicrobial activity of dyed fabrics were estimated. Regardless of extraction solvent type, colorant showed maximum absorption wavelength at 280 nm and 578 nm, which implied that tannin was the major pigment component of TCR. Also, through FT-IR spectrum result, it was confirmed that tannin of TCR methanol extract was hydrolysable tannin. But for the hot water extract, it was only assumed that its tannin was condenced tannin. Fabric dyed with hot water solvent extract showed higher dye uptake than fabric dyed with methanol solvent extract, dye uptake increasing by higher concentration of the dye, longer dyeing time and higher dyeing temperature. And the absorption curve between TCR extract and protein fiber was shaped in the form of Langmuir adsorption isotherm. Fabric dyed without mordant was yellow in color, and when dyed with mordant, fabric showed various colors depending on mordant types except Sn. Color fastness to washing was generally fine and color fastness to light was moderate. But color fastness to rubbing and dry cleaning was outstanding. Lastly, dyed fabrics showed very good antimicrobial activity of 99.9% against Staphylococcus aureus and Kiebsiella pneumoniae.

Changes in chlorophylls, chlorophyll degradation products and lutein in pistachio kernels (Pistacia vera L.) during roasting

Bright green pistachio kernels are desirable in the food industry and degradation of color is often associated with a loss in quality. Chlorophylls (a and b) and lutein are the major pigments in raw pistachios. The heat treatment of chlorophyll-containing foods results in color alteration, due to the conversion of chlorophylls (bright green color) to pheophytins and pyropheophytins (yellow-brown olive color). In this study, changes in the concentration of chlorophylls, chlorophyll degradation products and lutein in pistachios were monitored during oven roasting. An efficient, high performance liquid chromatography method with photodiode-array detection (HPLC-PDA) was developed to separate and quantitate these pigments in pistachios. Extractable chlorophylls a and b were higher in pistachio kernels roasted for 5 and 10min than in the raw kernels. The most drastic losses were observed with pheophytins a and b, which both decreased by approximately 85% after 60min of roasting. Pyropheophytins a and b increased significantly during roasting and were 10–12 fold higher in the pistachios roasted for 60min than in the raw pistachios. Extractable lutein concentration increased by 37% after 5min, but did not change significantly with longer roasting times. Initial increases in chlorophylls a and b and lutein were likely due to enhanced extractability with roasting. Color measurements of the pistachios corresponded with changes in concentration of chlorophyll pigments observed at the later roasting times. Interestingly, pyrochlorophylls a and b were detected in pistachios as confirmed by mass spectrometry. There are no prior reports of these compounds being detected in pistachios. We hypothesize that the conditions of pistachio roasting favor the formation of pyrochlorophylls. Color changes observed after oven roasting significantly affect quality and value perceptions of pistachios.

Flavobacterium faecale sp. nov., an agarase-producing species isolated from stools of Antarctic penguins.

Taxonomic studies were performed on an agarase-producing strain, designated WV33(T), isolated from faeces of Antarctic penguins. Cells of strain WV33(T) were Gram-staining-negative, strictly aerobic, orange and rod-shaped. Strain WV33(T) displayed agarase activity and was able to utilize galactose as a sole carbon source. 16S rRNA gene sequence analysis revealed that strain WV33(T) was closely related to Flavobacterium algicola TC2(T) (98.0% similarity), F. frigidarium ATCC 700810(T) (96.9%) and F. frigoris LMG 21922(T) (96.1%). The predominant cellular fatty acids were iso-C(15 : 1) G, iso-C(15 : 0), C(15 : 0), C(16 : 0) and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c). Menaquinone 6 (MK-6) was the sole quinone identified, and the major pigment was zeaxanthin. The major polar lipid was phosphatidylethanolamine. DNA-DNA relatedness of strain WV33(T) with respect to its closest phylogenetic neighbours was 25% for F. algicola NBRC 102673(T), 23% for F. frigidarium DSM 17623(T) and 21% for F. frigoris DSM 15719(T). The DNA G+C content of strain WV33(T) was 37±0.6 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain WV33(T) is concluded to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium faecale sp. nov. is proposed. The type strain is WV33(T) ( = KCTC 32457(T) = CECT 8384(T)).

Isolation and structural determination of C8-vinyl-bacteriochlorophyll d from the bciA and bchU double mutant of the green sulfur bacterium Chlorobaculum tepidum.

The mutant lacking enzymes BciA and BchU, that catalyzed reduction of the C8-vinyl group and methylation at the C20 position of bacteriochlorophyll (BChl) c, respectively, in the green sulfur bacterium Chlorobaculum tepidum, were constructed. This mutant accumulated C8-vinyl-BChl d derivatives, and a molecular structure of the major pigment was fully characterized by its NMR, mass, and circular dichroism spectra, as well as by chemical modification: (3(1) R)-8-vinyl-12-ethyl-(R[V,E])BChl d was confirmed as a new BChl d species in the cells. In vitro chlorosome-like self-aggregates of this pigment were prepared in an aqueous micellar solution, and formed more rapidly than those of (3(1) R)-8,12-diethyl-(R[E,E])BChl d isolated from the green sulfur bacterium Chlorobaculum parvum NCIB8327d synthesizing BChl d homologs. Their red-shifted Q y absorption bands were almost the same at 761nm, and the value was larger than those of in vitro self-aggregates of R[E,E]BChl c (737nm) and R[V,E]BChl c (726nm), while the monomeric states of the former gave Q y bands at shorter wavelengths than those of the latter. Red shifts by self-aggregation of the two BChl d species were estimated to be 110nm and much larger than those by BChls c (75nm for [E,E] and 64nm for [V,E]).

Anthocyanins in blackcurrant effectively prevent the formation of advanced glycation end products by trapping methylglyoxal

Carbonyl stress is the major consequence for advanced glycation end products (AGEs). Polyphenols have been shown to inhibit the formation of AGEs. However, little is known about whether anthocyanins contribute to trapping methylglyoxal (MGO) and reducing carbonyl stress. Blackcurrant (Ribes nigrum) extract (BE) is known to have high content of anthocyanins. When an aliquot of 7.5 mg/mL BE sample was incubated with 2.9 mM MGO in pH 7.4 phosphate buffer solution (PBS) for an hour, 36.75% MGO decrease was observed. The BE extract sample was separated and purified by Sephadex LH-20 and reverse phase C18 column chromatography. Delphinidin-3-rutinoside (D3R) and cyanidin-3-rutinoside (C3R) were identified as major pigments in BE sample. Some 71.45 and 78.72% of D3R and C3R, respectively, remained when they were incubated alone in a phosphate buffer solution at 37 °C for 1 h, but only 2.48 and 1.83% of D3R and C3R, respectively, remained when individually incubated with MGO. D3R- and C3R-mono-MGO adducts were characterized by HPLC-MSn.