Determination of Bioactive Compounds in the Juice of Pummelo (Citrus grandis Osbeck)

The juice of pummelo (Citrus grandis Osbeck) was analyzed to determine its composition of flavonoids, polymethoxyflavones, coumarins and psoralens. The analyses were carried out by HPLC using columns packed with small diameter Fused-Core® C18 particles to achieve high resolution in short analysis time. In addition, the profile of the native carotenoids present in the juice was determined using a C30 column. Identification of flavonoids was achieved by MS with ESI in negative mode; the MS acquisition of oxygenated heterocyclic compounds was performed in positive APCI; carotenoids were detected with a PDA detector. Nineteen native carotenoids were determined in pummelo juice for the first time. The composition of this juice is also discussed in comparison with other Citrus juices, especially grapefruit.

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Analytical Determination of Bioactive Compounds as an Indication of Fruit Quality

Journal of AOAC International ◽

10.5740/jaoacint.12-130 ◽

2012 ◽

Vol 95 (6) ◽

pp. 1725-1732 ◽

Cited By ~ 15

Author(s):

Yong Seo Park ◽

Buk-Gu Heo ◽

Kyung-Sik Ham ◽

Seong-Gook Kang ◽

Yang-Kyun Park ◽

...

Keyword(s):

Ethyl Acetate ◽

Bioactive Compounds ◽

Antioxidant Activities ◽

Three Dimensional ◽

Analytical Determination ◽

Antioxidant Power ◽

Ferric Reducing Antioxidant Power ◽

Antioxidant Capacity Assays ◽

First Time

Abstract The aim of this investigation was to determine the bioactive compounds in kiwifruit as an indication of quality after extraction using methanol and ethyl acetate. Using FTIR and three-dimensional fluorescence spectroscopy and electrospray ionization/MS, the contents of polyphenols, flavonoids, flavanols, and tannins, and the level of the antioxidant activity by 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt, 1, 1-diphenyl-2-picrylhydrazyl, ferric-reducing/antioxidant power, and cupric reducing antioxidant capacity assays were determined and compared. It was found that the methanol extracts of kiwifruit showed significantly higher amounts of bioactive compounds and antioxidant activities than the ethyl acetate extracts. The cultivar Bidan, in comparison with the classic Hayward, showed significantly higher bioactivity. For the first time, Bidan organic kiwifruit was analyzed for its antioxidant activities and compared with the widely consumed Hayward organic based on its bioactive compounds and fluorescence properties. Relatively high content of bioactive compounds and positive antioxidant and antiproliferative properties of kiwifruit determined by the advanced analytical methods justify its use as a source of valuable antioxidants. The methods used are applicable for bioactivity determination, in general, for any food products.

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Wenlock–Ludlow boundary interval revisited: new insights from the offshore facies of the Prague Synform, Czech Republic

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2015-0161 ◽

2016 ◽

Vol 53 (7) ◽

pp. 666-673 ◽

Cited By ~ 3

Author(s):

Petr Štorch ◽

Štěpán Manda ◽

Ladislav Slavík ◽

Zuzana Tasáryová

Keyword(s):

Czech Republic ◽

High Resolution ◽

Deep Water ◽

Middle Part ◽

Low Level ◽

First Time ◽

Stratigraphic Interval

Wenlock–Ludlow boundary beds exposed near Nesvačily in the Prague Synform are documented in terms of their lithology, faunal content, high-resolution record of 19 graptolite species, graptolite biostratigraphy, and conodont record. This is the first time in Bohemia and peri-Gondwanan Europe that a continuous graptolite-bearing section through upper ludensis – middle nilssoni biozones is described in detail to refine high-resolution biostratigraphy and correlation of the Wenlock–Ludlow boundary. Organic-rich shale, relatively rare nongraptolite fauna, and absence of bioturbation indicate a stable deep-water offshore setting with sporadic, low-level bottom oxygenation. The uninterrupted succession revealed a series of origination events of principal graptolite taxa employed in determination of the Wenlock–Ludlow boundary strata worldwide. Bohemograptus represented by B. praecox appeared as early as in the uppermost Wenlock ludensis Biozone. Bohemograptus praecox is later accompanied and replaced by B. bohemicus, associated with Uncinatograptus uncinatus. The lowest Neodiversograptus nilssoni marked the base of the Ludlow nilssoni Biozone. Speciation within Bohemograptus continued in the middle nilssoni Biozone when the robust B. butovicensis evolved from B. bohemicus. Colonograptus colonus shows its lowest occurrence in the middle part of the nilssoni Biozone together with the latest C. gerhardi. The monograptids are associated with abundant and diverse plectograptids that are at present mostly known from Baltica. Bohemograptus praecox sp. nov. and B. butovicensis ( Bouček, 1936 ) are described in the systematic part. The conodont Kockelella ortus absidata, found in the lower–middle part of the nilssoni Biozone, is consistent with a stratigraphic interval within Oz. bohemica and K. crassa conodont biozones.

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Von der „Blobology“ zur atomaren Auflösung der Kryo-Elektronenmikroskopie

BIOspektrum ◽

10.1007/s12268-020-1480-5 ◽

2020 ◽

Vol 26 (7) ◽

pp. 710-713

Author(s):

Holger Stark

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Structure Determination ◽

Protein Complexes ◽

Pharmaceutical Research ◽

New Drugs ◽

Cryo Electron Microscopy ◽

High Resolution Structure ◽

First Time

AbstractIt took almost a century to develop electron microscopy into a powerful method for high-resolution structure determination of proteins. Technical improvements in microscopy, detector technology, and image processing software contributed to the exponential growth of high-resolution structures of protein complexes determined by cryo-electron microscopy in recent years. We now succeeded in breaking another resolution barrier in cryo-electron microscopy and for the first time in achieving true atomic resolution, where single atoms in the protein can indeed be visualized individually. These improvements in cryo-EM indicate that the method will continue to gain importance, not only as a method for structure determination but also in the development of new drugs in pharmaceutical research.

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Direct determination of lead in bones using slurry sampling and high-resolution continuum source electrothermal atomic absorption spectrometry

Analytical Methods ◽

10.1039/c8ay02555j ◽

2019 ◽

Vol 11 (9) ◽

pp. 1254-1263 ◽

Cited By ~ 3

Author(s):

Lenka Husáková ◽

Tereza Šídová ◽

Lucie Ibrahimová ◽

Monika Svízelová ◽

Tomáš Mikysek

Keyword(s):

High Resolution ◽

Atomic Absorption Spectrometry ◽

Electrothermal Atomic Absorption Spectrometry ◽

Direct Determination ◽

Absorption Spectrometry ◽

Slurry Sampling ◽

Continuum Source ◽

First Time ◽

Environmentally Friendly Method

Development of a robust, sensitive, fast, accurate and environmentally friendly method enabling for the first time routine direct determination of Pb in bone samples by HR-CS-ETAAS.

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High-resolution microscopy of twin boundaries in gold

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126202 ◽

1987 ◽

Vol 45 ◽

pp. 260-261

Author(s):

William Krakow ◽

David A. Smith

Keyword(s):

High Resolution ◽

Specimen Preparation ◽

Gold Films ◽

Boundary Area ◽

Transmission Electron ◽

Recent Developments ◽

Tilt Boundaries ◽

High Resolution Microscopy ◽

Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

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High-Resolution Image Simulation of a Tilted Crystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179099 ◽

1990 ◽

Vol 48 (1) ◽

pp. 68-69

Author(s):

C. J. D. Hetherington

Keyword(s):

High Resolution ◽

Crystal Thickness ◽

Thin Specimen ◽

Atomic Structures ◽

Kikuchi Lines ◽

High Resolution Images ◽

Final Estimate ◽

Simulated Images ◽

Habit Planes

Most high resolution images are not directly interpretable but must be compared with simulations based on model atomic structures and appropriate imaging conditions. Typically, the only parameters that are adjusted, in addition to the structure models, are crystal thickness and microscope defocus. Small tilts of the crystal away from the exact zone axis have only rarely been considered. It is shown here that, in the analysis of an image of a silicon twin intersection, the crystal tilt could be accurately estimated and satisfactorily included in the simulations.The micrograph shown in figure 1 was taken as part of an HREM study of indentation-induced hexagonal silicon. In this instance, the intersection of two twins on different habit planes has driven the silicon into hexagonal stacking. However, in order to confirm this observation, and in order to investigate other defects in the region, it has been necessary to simulate the image taking into account the very apparent crystal tilt. The inability to orientate the specimen at the exact [110] zone was influenced by i) the buckling of the specimen caused by strains at twin intersections, ii) the absence of Kikuchi lines or a clearly visible Laue circle in the diffraction pattern of the thin specimen and iii) the avoidance of radiation damage (which had marked effects on images taken a few minutes later following attempts to realign the crystal.) The direction of the crystal tilt was estimated by observing which of the {111} planes remained close to edge-on to the beam and hence strongly imaged. Further refinement of the direction and magnitude of the tilt was done by comparing simulated images to experimental images in a through-focal series. The presence of three different orientations of the silicon lattice aided the unambiguous determination of the tilt. The final estimate of a 0.8° tilt in the 200Å thick specimen gives atomic columns a projected width of about 3Å.

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