4439-98-9Relevant academic research and scientific papers
Catalytic oxidative transformation of betulin to its valuable oxo-derivatives over gold supported catalysts: Effect of support nature
Kolobova,M?ki-Arvela,Grigoreva,Pakrieva,Carabineiro,Peltonen,Kazantsev,Bogdanchikova,Pestryakov,Murzin, D.Yu.
, p. 95 - 110 (2021)
Liquid-phase oxidation of betulin extracted from birch bark was studied over gold catalysts supported on a range of supports (hydrotalcite, ZrO2, ZnO, MgO, CeO2, La2O3, HMS and various alumina) with different morphology and properties. Gold catalysts as well as the corresponding supports were characterized by XRD, BET, ICP-OES, XPS and TEM. It was found that the nature of the support plays a decisive role in betulin oxidation over gold-based catalysts, expressed in the influence on the average size and distribution of gold nanoparticles and, thereby, on their catalytic performance (activity and selectivity) in betulin oxidation. Moreover, it was revealed that betulin oxidation catalyzed by gold is a structure sensitive reaction, requiring an optimal size of gold nanoparticles of ca. 3.3 nm. The most suitable support for gold was found to be alumina. Kinetic studies allowed determination of reaction orders and conditions favorable for selective formation of a particular oxo-derivative of betulin (betulone, betulinic and betulonic aldehydes, betulinic acid).
Pyrazine-Fused Triterpenoids Block the TRPA1 Ion Channel in Vitro and Inhibit TRPA1-Mediated Acute Inflammation in Vivo
M?ki-Opas, Ilari,H?m?l?inen, Mari,Moilanen, Lauri J.,Haavikko, Raisa,Ahonen, Tiina J.,Alakurtti, Sami,Moreira, Vania M.,Muraki, Katsuhiko,Yli-Kauhaluoma, Jari,Moilanen, Eeva
, p. 2848 - 2857 (2019)
TRPA1 is a nonselective cation channel, most famously expressed in nonmyelinated nociceptors. In addition to being an important chemical and mechanical pain sensor, TRPA1 has more recently appeared to have a role also in inflammation. Triterpenoids are natural products with anti-inflammatory and anticancer effects in experimental models. In this paper, 13 novel triterpenoids were created by synthetically modifying betulin, an abundant triterpenoid of the genus Betula L., and their TRPA1-modulating properties were examined. The Fluo 3-AM protocol was used in the initial screening, in which six of the 14 tested triterpenoids inhibited TRPA1 in a statistically significant manner. In subsequent whole-cell patch clamp recordings, the two most effective compounds (pyrazine-fused triterpenoids 8 and 9) displayed a reversible and dose- and voltage-dependent effect to block the TRPA1 ion channel at submicromolar concentrations. Interestingly, the TRPA1 blocking action was also evident in vivo, as compounds 8 and 9 both alleviated TRPA1 agonist-induced acute paw inflammation in mice. The results introduce betulin-derived pyrazine-fused triterpenoids as promising novel antagonists of TRPA1 that are potentially useful in treating diseases with a TRPA1-mediated adverse component.
Oxidation of betulin and its monoacetates by "activated" DMSO
Ashavina,Flekhter,Galin,Kabalnova,Baltina,Tolstikov
, p. 207 - 211 (2003)
The oxidation of betulin and its 3-O- and 28-O-acetates by "activated" dimethylsulfoxide was investigated.
Structural modifications of 2,3-indolobetulinic acid: Design and synthesis of highly potent α-glucosidase inhibitors
Khusnutdinova, Elmira F.,Petrova, Anastasiya V.,Thu, Ha Nguyen Thi,Tu, Anh Le Thi,Thanh, Tra Nguyen,Thi, Cham Ba,Babkov, Denis A.,Kazakova, Oxana B.
, (2019)
A series of nineteen nitrogen-containing lupane triterpenoids was obtained by modification of C2, C3, C20 and C28 positions of betulonic acid and their α-glucosidase inhibiting activity was investigated. Being a leader compound from our previous study, 2,3-indolo-betulinic acid was used as the main template for different modifications at C-(28)-carboxyl group to obtain cyano-, methylcyanoethoxy-, propargyloxy- and carboxamide derivatives. 20-Oxo- and 29-hydroxy-20-oxo-30-nor-analogues of 2,3-indolo-betulinic acid were synthesized by ozonolysis of betulonic acid followed by Fischer indolization reaction. To compare the influence of the fused indole or the seven-membered A-ring on the inhibitory activity, lupane A-azepanones with different substituents at C28 were synthesized. The structure-activity relationships revealed that the enzyme inhibition activity dramatically increased (up to 4730 times)when the carboxylic group of 2,3-indolo-betulinic acid was converted to the corresponding amide. Thus, the IC50 values for glycine amide and L-phenylalanine amides were 0.04 and 0.05 μM, respectively. This study also revealed that 2,3-indolo-platanic acid is 4.5 times more active than the parent triterpenoid with IC50 of 0.4 μM. Molecular modeling suggested that improved potency is due to additional polar interactions formed between C28 side chain and a sub-pocket of the α-glucosidase allosteric site.
Chemical transformations of betulonic aldehyde
Semenenko,Babak,Eremina,Gella,Shishkina,Musatov,Lipson
, p. 249 - 260 (2016)
Chemical transformations of 3-oxolup-20(29)-en-28-al in oxidation, reduction, reductive amination, aldol crotonic condensation, cyclopropanation, Grignard, and Wittig reactions were investigated. The structure of reaction products was established by X-ray diffraction (XRD) analysis.
Alkylidene branched lupane derivatives: Synthesis and antitumor activity
Csuk, Rene,Stark, Sebastian,Nitsche, Christoph,Barthel, Alexander,Siewert, Bianka
, p. 337 - 345 (2012)
Several novel alkylidene branched lupane derivatives have been prepared. Many of these compounds showed a significant cytotoxicity. The most active compound, 2-methylene-betulonic acid, showed IC50 values between 0.2 and 0.6 μM for 15 different human cancer cell lines. Cytotoxicity can be improved by encapsulation in liposomes. These compounds act by triggering apoptotic cell death as shown by DNA-laddering experiments and acridine orange/ethidium bromide staining.
Enhancement of the antioxidant and skin permeation properties of betulin and its derivatives
Duchnik, Wiktoria,Günther, Andrzej,Klimowicz, Adam,Kucharski, ?ukasz,Makuch, Edyta,Nowak, Anna,Pe?ech, Robert
, (2021/06/21)
This study investigated the antioxidant activity DPPH, ABTS, and Folin–Ciocalteu methods of betulin (compound 1) and its derivatives (compounds 2–11). Skin permeability and accumulation associated with compounds 1 and 8 were also examined. Identification of the obtained products (compound 2–11) and betulin isolated from plant material was based on the analysis of1H-NMR and13C-NMR spectra. The partition coefficient was calculated to determine the lipophilicity of all compounds. In the next stage, the penetration through pig skin and its accumulation in the skin were evaluated of ethanol vehicles containing compound 8 (at a concentration of 0.226 mmol/dm3), which was characterized by the highest antioxidant activity. For comparison, penetration studies of betulin itself were also carried out. Poor solubility and the bioavailability of pure compounds are major constraints in combination therapy. However, we observed that the ethanol vehicle was an enhancer of skin permeation for both the initial betulin and compound 8. The betulin 8 derivative showed increased permeability through biological membranes compared to the parent betulin. The paper presents the transformation of polycyclic compounds to produce novel derivatives with marked antioxidant activities and as valuable intermediates for the pharmaceutical industry. Moreover, the compounds contained in the vehicles, due to their mechanism of action, can have a beneficial effect on the balance between oxidants and antioxidants in the body, minimizing the effects of oxidative stress. The results of this work may contribute to knowledge regarding vehicles with antioxidant potential. The use of vehicles for this type of research is therefore justified.
Synthesis of α,ω-Diketodiesters from Betulin
Ishmuratov, G. Yu.,Sayakhov, R. R.,Talipov, R. F.,Vydrina, V. A.,Yakovleva, M. P.,Zileeva, Z. R.
, p. 706 - 711 (2021/07/31)
A new synthesis of 3-oxo-28-hydroxylup-20(29)-ene from the available natural triterpenoid betulin was developed. α,ω-Diketodiesters were prepared for the first time by different methods from 3-oxo-28-hydroxylup-20(29)-ene and a series of natural dicarboxylic acids. Steglich reaction conditions gave the highest yields. One of the synthesized α,ω-diketodiesters was moderately active in vitro against A-549 lung carcinoma.
Anti-tumor betulinol derivative and preparation method thereof
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Paragraph 0006; 0026-0027, (2021/07/28)
The invention discloses an anti-tumor betulin derivative and a preparation method thereof. The preparation method comprises the following steps: adding betulin into a reactor, oxidizing hydroxyl by using a mixed solution of sodium dichromate and sulfuric acid, carrying out acylating chlorination on thionyl chloride, carrying out aminolysis under an alkaline condition, and finally crystallizing by using ethanol to obtain the betulin derivative with a novel structure. Pathological experiments show that compared with cis-platinum which is commonly used at present, the betulin derivative has remarkable inhibitory activity on breast cancer cells, human ovarian cancer cells, human lung cancer cells and human liver cancer cells. The method is simple in route, simple to operate and high in yield, the used reagents are common reagents, and particularly, the preparation cost of the technical route of the preparation method is obviously reduced, and the reaction conditions are mild.
Oxidation of a wood extractive betulin to biologically active oxo-derivatives using supported gold catalysts
Kolobova, Ekaterina N.,Pakrieva, Ekaterina G.,Carabineiro, Sónia A. C.,Bogdanchikova, Nina,Kharlanov, Andrey N.,Kazantsev, Sergey O.,Hemming, Jarl,M?ki-Arvela, P?ivi,Pestryakov, Alexey N.,Murzin, Dmitry Yu.
, p. 3370 - 3382 (2019/06/24)
Betulin (90-94%) was extracted from birch with a non-polar solvent and recrystallized from 2-propanol. Liquid-phase oxidation of betulin aimed at obtaining its biologically active oxo-derivatives (betulone, betulonic and betulinic aldehydes), exhibiting e.g. antitumor, anti-inflammatory, antiparasitic, anticancer and anti-HIV properties, was demonstrated for the first time over gold-based catalysts. Gold was deposited on pristine TiO2 and the same support modified with ceria and lanthana, followed by pretreatment with a H2 or O2 atmosphere. The catalysts were characterized by XRD, BET, ICP, TEM, XPS, DRIFT CO, TPD of NH3 and CO2 methods. The nature of the support, type of modification and the pretreatment atmosphere through the metal-support interactions significantly influenced the average particle size of gold, its distribution and the electronic state of gold, as well as the acid-base properties and, thereby, the catalytic performance (activity and selectivity) in betulin oxidation. Au/La2O3/TiO2 pretreated in H2 displayed the highest catalytic activity in betulin oxidation among the studied catalysts with selectivities to betulone, betulonic and betulinic aldehydes of 42, 32 and 27%, respectively, at 69% conversion. Side reactions resulting in oligomerization/polymerization products occurred on the catalyst surface with the participation of strong acid sites, diminishing the yield of the desired compounds. The latter was improved by adding hydrotalcite with the basic properties to the reaction mixture containing the catalyst. Kinetic modelling through numerical data fitting was performed to quantify the impact of such side reactions and determine the values of rate constants.
