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26-593: Cinnamtannin B1 is a condensed tannin found in Cinnamomum verum . It falls under the category of type A proanthocyanidin . Cinnamon could potentially exhibit pharmacological effects in treating type 2 diabetes mellitus and insulin resistance . The plant material predominantly employed in the study was sourced from Chinese cinnamon (see Chinese cinnamon's medicinal uses ). Recent phytochemical research has suggested that cinnamtannin B1, extracted from C. Verum , might have

52-469: A SAXS instrument, a monochromatic beam of X-rays is brought to a sample from which some of the X-rays scatter, while most simply go through the sample without interacting with it. The scattered X-rays form a scattering pattern which is then detected at a detector which is typically a 2-dimensional flat X-ray detector situated behind the sample perpendicular to the direction of the primary beam that initially hit

78-695: A catechin nature rather than of the gallic type present in temperate woods . Condensed tannins can be recovered from Lithocarpus glaber or can be found in Prunus sp. The bark of Commiphora angolensis contains condensed tannins. Commercial sources of condensed tannins are plants such as quebracho wood ( Schinopsis lorentzii ), mimosa bark ( Acacia mollissima ), grape seeds ( Vitis vinifera ), pine barks and spruce barks. Condensed tannins are formed in tannosomes , specialized organelles, in Tracheophytes, i.e. vascular plants . Pycnogenol

104-502: A family of X-ray scattering techniques that are used in the characterization of materials. In the case of biological macromolecules such as proteins , the advantage of SAXS over crystallography is that a crystalline sample is not needed. Furthermore, the properties of SAXS allow investigation of conformational diversity in these molecules. Nuclear magnetic resonance spectroscopy methods encounter problems with macromolecules of higher molecular mass (> 30–40 kDa ). However, owing to

130-451: A laboratory source or synchrotron light which provides a higher X-ray flux . It is possible to enhance the X-ray scattering yield by matching the energy of X-ray source to a resonant absorption edge in as it is done for resonant inelastic X-ray scattering . Different from standard RIXS measurements, the scattered photons are considered to have the same energy as the incident photons. In

156-564: A mass spectrometer with an electrospray ionization source, only able to form ions with smaller molecules. The butanol– hydrochloric acid –iron assay (Porter assay) is a colorimetric assay. It is based on acid catalysed oxidative depolymerization of condensed tannins into corresponding anthocyanidins . The method has also been used for determination of bound condensed tannins, but has limitations. This reagent has recently been improved considerably by inclusion of acetone. The condensed tannins can nevertheless undergo acid-catalyzed cleavage in

182-628: A potential therapeutic impact on type 2 diabetes , with the exception of postmenopausal patients studied using Cinnamomum aromaticum . Cinnamtannin B1 possesses multiple phenolic hydroxyl groups and is noted for its antioxidant properties, antimicrobial activities, and ability to inhibit platelet aggregation, which could contribute to the protection of damaged tissues in wounds. Condensed tannin They are called proanthocyanidins as they yield anthocyanidins when depolymerized under oxidative conditions. Different types of condensed tannins exist, such as

208-517: A type of substitution reaction in organic chemistry, involving a carbocation intermediate under strongly acidic conditions in polar protic solvents like methanol . The reaction leads to the formation of free and derived monomers that can be further analyzed. The free monomers correspond to the terminal units of the condensed tannins chains. If thiolysis is done directly on plant material (rather than on purified tannins), it is, however, important to subtract naturally occurring free flavanol monomers from

234-652: Is a dietary supplement derived from extracts from maritime pine bark, is standardised to contain 70% procyanidin and is marketed with claims it can treat many conditions; however, according to a 2020 Cochrane review , the evidence is insufficient to support its use for the treatment of any chronic disorder. Condensed tannins can be characterised by a number of modern techniques including depolymerisation, asymmetric flow field flow fractionation , small-angle X-ray scattering and MALDI-TOF mass spectrometry. Their interactions with proteins can be studied by isothermal titration calorimetry and this provides information on

260-416: Is achieved by analyzing the elastic scattering behaviour of X-rays when travelling through the material, recording their scattering at small angles (typically 0.1 – 10°, hence the "Small-angle" in its name). It belongs to the family of small-angle scattering (SAS) techniques along with small-angle neutron scattering , and is typically done using hard X-rays with a wavelength of 0.07 – 0.2 nm . Depending on

286-466: The X-ray beam to a small circular or elliptical spot that illuminates the sample. Thus the scattering is centro-symmetrically distributed around the primary X-ray beam and the scattering pattern in the detection plane consists of circles around the primary beam. Owing to the small illuminated sample volume and the wastefulness of the collimation process—only those photons are allowed to pass that happen to fly in

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312-959: The procyanidins , propelargonidins , prodelphinidins , profisetinidins , proteracacinidins , proguibourtinidins or prorobinetidins . All of the above are formed from flavan-3-ols , but flavan-3,4-diols, called ( leucoanthocyanidin ) also form condensed tannin oligomers, e.g. leuco-fisetinidin form profisetinidin , and flavan-4-ols form condensed tannins, e.g. 3',4',5,7-flavan-4-ol form proluteolinidin (luteoforolor). One particular type of condensed tannin, found in grape, are procyanidins , which are polymers of 2 to 50 (or more) catechin units joined by carbon-carbon bonds. These are not susceptible to being cleaved by hydrolysis . While many hydrolyzable tannins and most condensed tannins are water-soluble, several tannins are also highly octanol -soluble. Some large condensed tannins are insoluble. Differences in solubilities are likely to affect their biological functions. Tannins of tropical woods tend to be of

338-543: The Sun's corona. Only if the Moon blocks out the main light source does the corona become visible. Likewise, in SAXS the non-scattered beam that merely travels through the sample must be blocked, without blocking the closely adjacent scattered radiation. Most available X-ray sources produce divergent beams and this compounds the problem. In principle the problem could be overcome by focusing

364-534: The affinity constant, enthalpy and stoichiometry in the tannin-protein complex. Depolymerisation reactions are mainly analytical techniques but it is envisaged to use them as means to produce molecules for the chemical industry derived from waste products, such as bark from the wood industry or pomaces from the wine industry. Depolymerisation is an indirect method of analysis allowing to gain information such as average degree of polymerisation , percentage of galloylation, etc. The depolymerised sample can be injected on

390-433: The angular range in which a clear scattering signal can be recorded, SAXS is capable of delivering structural information of dimensions between 1 and 100 nm, and of repeat distances in partially ordered systems of up to 150 nm. USAXS (ultra-small angle X-ray scattering) can resolve even larger dimensions, as the smaller the recorded angle, the larger the object dimensions that are probed. SAXS and USAXS belong to

416-403: The beam only in one dimension (rather than two as for point collimation) so that the beam cross-section is a long but narrow line. The illuminated sample volume is much larger compared to point-collimation and the scattered intensity at the same flux density is proportionally larger. Thus measuring times with line-collimation SAXS instruments are much shorter compared to point-collimation and are in

442-401: The beam, but this is not easy when dealing with X-rays and was previously not done except on synchrotrons where large bent mirrors can be used. This is why most laboratory small angle devices rely on collimation instead. Laboratory SAXS instruments can be divided into two main groups: point-collimation and line-collimation instruments: Point-collimation instruments have pinholes that shape

468-417: The concentration of terminal units that are released during depolymerisation. Reactions are generally made in methanol , especially thiolysis, as benzyl mercaptan has a low solubility in water. They involve a moderate (40 to 90 °C (104 to 194 °F)) heating for a few minutes. Epimerisation may happen. Phloroglucinolysis can be used for instance for proanthocyanidins characterisation in wine or in

494-399: The grape seed and skin tissues. Thioglycolysis can be used to study proanthocyanidins or the oxidation of condensed tannins. It is also used for lignin quantitation . Reaction on condensed tannins from Douglas fir bark produces epicatechin and catechin thioglycolates . Condensed tannins from Lithocarpus glaber leaves have been analysed through acid-catalyzed degradation in

520-451: The presence of cysteamine . Small-angle X-ray scattering Small-angle X-ray scattering ( SAXS ) is a small-angle scattering technique by which nanoscale density differences in a sample can be quantified. This means that it can determine nanoparticle size distributions, resolve the size and shape of (monodisperse) macromolecules , determine pore sizes, characteristic distances of partially ordered materials, and much more. This

546-406: The presence of (an excess of) a nucleophile like phloroglucinol (reaction called phloroglucinolysis), benzyl mercaptan (reaction called thiolysis ), thioglycolic acid (reaction called thioglycolysis) or cysteamine . These techniques are generally called depolymerisation and give information such as average degree of polymerisation or percentage of galloylation. These are SN1 reactions ,

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572-482: The random orientation of dissolved or partially ordered molecules, the spatial averaging leads to a loss of information in SAXS compared to crystallography. SAXS is used for the determination of the microscale or nanoscale structure of particle systems in terms of such parameters as averaged particle sizes, shapes, distribution, and surface-to-volume ratio. The materials can be solid or liquid and they can contain solid, liquid or gaseous domains (so-called particles) of

598-622: The range of minutes. A disadvantage is that the recorded pattern is essentially an integrated superposition (a self- convolution ) of many adjacent pinhole patterns. The resulting smearing can be easily removed using model-free algorithms or deconvolution methods based on Fourier transformation, but only if the system is isotropic. Line collimation is of great benefit for any isotropic nanostructured materials, e.g. proteins, surfactants, particle dispersion and emulsions. SAXS instrument manufacturers include Anton Paar , Austria; Bruker AXS , Germany; Hecus X-Ray Systems Graz, Austria; Malvern Panalytical .

624-486: The right direction—the scattered intensity is small and therefore the measurement time is in the order of hours or days in case of very weak scatterers. If focusing optics like bent mirrors or bent monochromator crystals or collimating and monochromating optics like multilayers are used, measurement time can be greatly reduced. Point-collimation allows the orientation of non-isotropic systems ( fibres , sheared liquids) to be determined. Line-collimation instruments restrict

650-638: The same or another material in any combination. Not only particles, but also the structure of ordered systems like lamellae , and fractal -like materials can be studied. The method is accurate, non-destructive and usually requires only a minimum of sample preparation. Applications are very broad and include colloids of all types including interpolyelectrolyte complexes, micelles , microgels, liposomes , polymersomes , metals, cement, oil, polymers , plastics, proteins , foods and pharmaceuticals and can be found in research as well as in quality control. The X-ray source can be

676-411: The sample. The scattering pattern contains the information on the structure of the sample. The major problem that must be overcome in SAXS instrumentation is the separation of the weak scattered intensity from the strong main beam. The smaller the desired angle, the more difficult this becomes. The problem is comparable to one encountered when trying to observe a weakly radiant object close to the Sun, like

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