The Study of the Kinetics of Obtaining Betulin and Extractive Substances from the Birch Tree Bark

2017 ◽  
Vol 29 ◽  
pp. 42-47
Author(s):  
Sergei I. Tretiakov ◽  
Elena N. Koptelova ◽  
Natalia A. Kutakova ◽  
Nina V. Bagretsova ◽  
Nadezhda L. Voropaeva
Keyword(s):  
Tree Bark ◽  
Birch Bark ◽  
Hydrodynamic Conditions ◽  
Food Industries ◽  
Plywood Industry ◽  
Birch Tree ◽  
Extractive Substances ◽  
Bioactive Agents ◽  
The Given ◽  
Kinetics Of

Birch bark attracts attention of researchers as a source of betulin and other extractive substances (ES) useful for chemical, pharmaceutical and food industries. A challenge is to develop an efficient way of obtaining these bioactive agents. This paper presents a microwave-assisted technique of extracting these substances from the waste birch bark of the plywood industry. The kinetics of the extraction was investigated. With the process going on in the pore-diffusion area, the hydrodynamic conditions of the operation are discussed. An algorithm for calculating the kinetics of the procedure was developed and experimentally confirmed. The estimations for the process were made at constant values of the internal diffusion coefficient. The value of the coefficient was found to be a function of the birch bark fragments dimensions. An equation was established to estimate the duration of the extraction to obtain the given yield of ES and betulin.

scholarly journals Anti-Inflammatory and Anticancer Properties of Birch Bark-Derived Betulin: Recent Developments

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2663
Author(s):  
Hardeep Singh Tuli ◽  
Katrin Sak ◽  
Dhruv Sanjay Gupta ◽  
Ginpreet Kaur ◽  
Diwakar Aggarwal ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Tree Bark ◽  
Antitumor Action ◽  
Special Focus ◽  
Birch Bark ◽  
Related Factor ◽  
Nuclear Factor ◽  
Anticancer Activities ◽  
Birch Tree ◽  
Anti Inflammatory

Birch tree bark-derived betulin has attracted scientific interest already for several centuries, being one of the first natural products identified from plants. However, the cellular events regulated by betulin and precise molecular mechanisms under these processes have been begun to be understood only recently. Today, we know that betulin can exert important anticancer activities through modulation of diverse cellular pathways. In this review article, betulin-regulated molecular signaling is unraveled and presented with a special focus on its participation in anti-inflammatory processes, especially by modulating nuclear factor-κB (NF-κB), prostaglandin/COX, and nuclear factor erythroid2-related factor 2 (Nrf2)-mediated cascades. By regulating these diverse pathways, betulin can not only affect the development and progression of different cancers, but also enhance the antitumor action of traditional therapeutic modalities. It is expected that by overcoming the low bioavailability of betulin by encapsulating it into nanocarriers, this promising natural compound may provide novel possibilities for targeting inflammation-related cancers.

scholarly journals Evaluation of Betulin and Betulinic Acid Content in Birch Bark from Different Forestry Areas of Western Carpathians

2012 ◽  
Vol 40 (2) ◽  
pp. 99 ◽  
Author(s):  
Liviu HOLONEC ◽  
Floricuta RANGA ◽  
Diana CRAINIC ◽  
Alina TRUTA ◽  
Carmen SOCACIU
Keyword(s):  
Betulinic Acid ◽  
Acid Content ◽  
High Performance ◽  
Uv Detection ◽  
Western Carpathians ◽  
Tree Bark ◽  
Birch Bark ◽  
Birch Tree ◽  
Birch Trees ◽  
Absolute Concentrations

In order to evaluate the content of betulin and betulinic acids in Birch barks originating from Western Carpathians, Transylvania (Romania) forests, in relation with the location of birch trees, it was recorded the geographic and vegetation conditions at the specific locations of each type of sample. Two groups of birch tree bark (totally 10 samples) were collected, from two regions, pasture surfaces where birch trees appeared spontaneously (samples 1 to 5) and another group from forests of combined trees, including mainly pine trees (samples 6 to 10). The identification and quantitation of betulin and betulinic acid were made by High Performance Liquid Chromatography with UV detection. In the first region it has been found mean concentrations of 126.85 ± 12.56 mg/g betulin bark while acid betulinic had average values of 12.78 ± 1.26 mg/g bark. In the second region we found mean concentrations of 89.84 ± 8.43 mg/g betulin of bark while acid betulinic had average values of 10.60 ± 0.97 mg/g bark. Statistically, significant differences were noticed between the two regions, the first region being richer in these molecules. Generally, the percentage of betulinic acid was around 11.23% against betulin, higher in the second region, even the absolute concentrations were lower for both molecules. These data are useful indicators of the potential offered by birch bark sources found in Transylvania region, to obtain extracts enriched in betulin and betulinic acid.

Complexation with Hydroxypropyl-gama-Cyclodextrin of Birch Tree Extract Physico-chemical Characterisation of their Binary Products

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Codruta Soica ◽  
Cristina A. Dehelean ◽  
Valentin Ordodi ◽  
Diana Antal ◽  
Vicentiu Vlaia
Keyword(s):  
Inclusion Complexes ◽  
Water Solubility ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Bark Extract ◽  
Birch Bark ◽  
Preparation Methods ◽  
Birch Tree ◽  
Physico Chemical

Birch bark contains important pentacyclic triterpens that determine an anticancer, anti-inflammatory and antiviral activity. The compounds can be extracted by simple procedures with organic solvents. The major problem of this type of triterpens is their low water solubility which can be increased by physical procedures like cyclodextrin complexation. The aim of present study was to analyse the products between birch bark extract and hydroxypropyl-g -cyclodextrin. Hydroxypropyl-g -cyclodextrin (HPGCD) was used as a host to improve its solubility in water, via inclusion complex formation. In order to obtain the inclusion complexes, 1:2 molar ratio and two preparation methods (physical mixing, kneading) were used. The inclusion complexes were analyzed by in vitro dissolution tests, thermal analysis and X-ray diffraction.

Kinetics of catalytic conversion of methanol at higher pressures

1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Low Temperature ◽  
Reaction Kinetics ◽  
Water Vapour ◽  
Kinetic Data ◽  
Catalytic Conversion ◽  
The Given ◽  
Kinetics Of

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.

scholarly journals Study of Molten Salt Corrosion of Superni-75 using Termogravimetric Technique

1970 ◽  
Vol 3 (2) ◽  
pp. 77-82 ◽  
Author(s):  
TS Sidhu ◽  
S Prakash ◽  
RD Agrawal
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Hot Corrosion ◽  
Corrosion Behaviour ◽  
Thick Layer ◽  
X Ray Diffraction ◽  
Salt Corrosion ◽  
Marine Engineering ◽  
The Given ◽  
Kinetics Of

The present study aims to evaluate the hot corrosion behaviour of the Ni-based alloy Superni- 75 in the molten salt environment of Na2SO-60%V2O5 at 900°C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction, scanning electron microscopy/energy-dispersive analysis and electron probe microanalysis techniques were used to analyse the corrosion products. Superni-75 has successfully provided the hot corrosion resistance to the given molten salt environment. The hot corrosion resistance of the Superni-75 has been attributed to the formation of uniform, homogeneous and adherent thick layer of the scale consisting mainly of oxides of nickel and chromium, and refractory Ni(VO3)2. These oxides and refractory nickel vanadates have blocked the penetration of oxygen and other corrosive species to the substrate. Keywords: Hot corrosion, nickel-based alloy, superalloy, molten salt environment   DOI: 10.3329/jname.v3i2.922 Journal of Naval Architecture and Marine Engineering 3(2006) 77-82

scholarly journals Increasing the time resolution of single-molecule experiments with Bayesian inference

2017 ◽  
Author(s):  
Colin D. Kinz-Thompson ◽  
Ruben L. Gonzalez
Keyword(s):  
Bayesian Inference ◽  
Single Molecule ◽  
Time Resolution ◽  
Rate Constants ◽  
Computational Approach ◽  
Biomolecular Systems ◽  
Time Resolved ◽  
The Given ◽  
Kinetics Of ◽  
Resolution Data

AbstractMany time-resolved, single-molecule biophysics experiments seek to characterize the kinetics of biomolecular systems exhibiting dynamics that challenge the time resolution of the given technique. Here we present a general, computational approach to this problem that employs Bayesian inference to learn the underlying dynamics of such systems, even when they are much faster than the time resolution of the experimental technique being used. By accurately and precisely inferring rate constants, our Bayesian Inference for the Analysis of Sub-temporal-resolution Data (BIASD) approach effectively enables the experimenter to super-resolve the poorly resolved dynamics that are present in their data.

scholarly journals Near-equilibrium growth from borophene edges on silver

2019 ◽  
Vol 5 (9) ◽  
pp. eaax0246 ◽  
Author(s):  
Zhuhua Zhang ◽  
Andrew J. Mannix ◽  
Xiaolong Liu ◽  
Zhili Hu ◽  
Nathan P. Guisinger ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Chemical Potential ◽  
Two Dimensional ◽  
Experimental Characterization ◽  
Two Dimensional Materials ◽  
Low Energies ◽  
The Given ◽  
Kinetics Of ◽  
Equilibrium Growth ◽  
Energy Pathways

Two-dimensional boron, borophene, was realized in recent experiments but still lacks an adequate growth theory for guiding its controlled synthesis. Combining ab initio calculations and experimental characterization, we study edges and growth kinetics of borophene on Ag(111). In equilibrium, the borophene edges are distinctly reconstructed with exceptionally low energies, in contrast to those of other two-dimensional materials. Away from equilibrium, sequential docking of boron feeding species to the reconstructed edges tends to extend the given lattice out of numerous polymorphic structures. Furthermore, each edge can grow via multiple energy pathways of atomic row assembly due to variable boron-boron coordination. These pathways reveal different degrees of anisotropic growth kinetics, shaping borophene into diverse elongated hexagonal islands in agreement with experimental observations in terms of morphology as well as edge orientation and periodicity. These results further suggest that ultrathin borophene ribbons can be grown at low temperature and low boron chemical potential.

Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ali Pourjavadi ◽  
Mohammad Sadeghi ◽  
Mohammad Mahmodi Hashemi ◽  
Hossein Hosseinzadeh
Keyword(s):  
Weight Ratio ◽  
Ammonium Persulfate ◽  
Switching Behavior ◽  
Polymerization Reaction ◽  
Sodium Acrylate ◽  
Swelling Kinetics ◽  
Superabsorbent Hydrogel ◽  
Swelling Capacity ◽  
Bioactive Agents ◽  
Kinetics Of

AbstractIn this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers was also investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1.0 and 13.0. It showed a reversible pH-responsive behavior at pHs 2.0 and 7.0. This on-off switching behavior makes the synthesized hydrogels an excellent candidate for controlled delivery of bioactive agents. Finally, the swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated.

SEARCH FOR A SOURCE OF TRITERPENE ACIDS IN RUSSIAN BIRCHES

2020 ◽  
pp. 277-282
Author(s):  
Dmitriy Nikolayevich Vedernikov ◽  
Ol'ga Alekseyevna Eregina ◽  
Anna Viktorovna Shemyakina
Keyword(s):  
Raw Materials ◽  
Silver Birch ◽  
Absolute Calibration ◽  
Quantitative Composition ◽  
Birch Bark ◽  
Gas Liquid Chromatography ◽  
Leningrad Region ◽  
Outer Bark ◽  
Triterpene Acids ◽  
Birch Tree

The composition of triterpene acids and triterpene alcohols of the outer bark of a damaged silver birch tree (Betula pendula Roth.) the outer bark of silver birch branches, the outer bark of Betula davurica Pall., B. mandshurica (Regel) Nakai, B. platyphylla Sucacz. and B. costata Trautv. is considered. Silver birch bark was harvested in the Leningrad region. The bark of other species of birches was harvested in the Khabarovsk region. The qualitative composition of triterpene compounds was determined by chromatography-mass spectrometry. The quantitative composition was determined by gas-liquid chromatography and absolute calibration. Butyl esters of acids were preliminarily prepared for GLC analysis of triterpene acids. The outer bark of the eastern species of birches contains significantly more betulinic and oleanolic acid than silver birch. The relative content of triterpene acids is greater in the outer bark of branches and in the bark of damaged silver birches. The increase in acid content is apparently associated with the desire to heal a wound. The main component among the triterpenoids of the investigated raw materials is betulin. For the separation of acids from other triterpenoids, various solubilities of the compounds in solvents and the ability of acids to form poorly soluble salts were used.

Sign in / Sign up

Export Citation Format

Share Document