3516-95-8Relevant academic research and scientific papers
Phenolic compounds from Peperomia obtusifolia
Tanaka, Toshiyuki,Asai, Fujio,Iinuma, Munekazu
, p. 229 - 232 (1998)
From the aerial parts of Pepermia obtusifolia, five phenolic compounds bearing a methyl, an isoprenyl and a geranyl group on a benzene ring core have been isolated. The structures were determined by the spectroscopic analysis including 2D NMR techniques and synthesis.
Structure-activity relationship study of antitrypanosomal chalcone derivatives using multivariate analysis
Gomes, Kaio S.,da Costa-Silva, Thais A.,Oliveira, Igor H.,Aguilar, Andrea M.,Oliveira-Silva, Diogo,Uemi, Miriam,Silva, Wender A.,Melo, Lennine R.,Andrade, Carlos Kleber Z.,Tempone, Andre G.,Baldim, Jo?o L.,Lago, Jo?o Henrique G.
, p. 1459 - 1462 (2019)
Chagas disease represents one of several neglected diseases with a reduced number of chemotherapeutical drugs including the highly toxic compounds benznidazole and nifurtimox. In this sense, natural products represent an import scaffold for the discovery of new biologically active compounds, in which chalcones are promising representatives due to their antitrypanosomal potential. In this work, a series of 36 chalcone derivatives were synthesized and tested against trypomastigotes of Trypanosoma cruzi. In addition, a detailed investigation on their molecular features was performed. The obtained results suggest that certain molecular features are fundamental for an efficient antitrypanosomal potential of chalcones, such as allylic groups, α,β-unsaturated carbonyl system, and aromatic hydroxyl groups. These results were obtained based on the interpretation of machine-learning and multivariate statistical methods, which revealed the essential characteristics of chalcone prototypes against trypomastigotes of T. cruzi.
Solid-phase synthesis of β-mono-substituted ketones and an application to the synthesis of a library of phlorizin derivatives
Tanaka, Hiroshi,Zenkoh, Tatsuya,Setoi, Hiroyuki,Takahashi, Takashi
, p. 1427 - 1430 (2002)
We describe a novel reaction sequence for the solid-phase synthesis of β-mono-substituted ketones. The methodology involves an aldol condensation reaction, followed by reduction of the resultant double bond and allows the introduction of a range of alkyl chains to solid-linked ketones at α position. Using the methodology we accomplished the synthesis of phlorizin library of 132 compounds using 43 aldehydes and four glycosyl bromides.
Stereoselective reduction of flavanones by marine-derived fungi
Birolli, Willian G.,Nitschke, Marcia,Porto, André Luiz M.,Santos, Darlisson de A.,de Matos, Iara L.
, (2021/08/13)
Biotransformation is an alternative with great potential to modify the structures of natural and synthetic flavonoids. Therefore, the bioreduction of synthetic halogenated flavanones employing marine-derived fungi was described, aiming the synthesis of flavan-4-ols 3a-g with high enantiomeric excesses (ee) of both cis- and trans-diastereoisomers (up to >99% ee). Ten strains were screened for reduction of flavanone 2a in liquid medium and in phosphate buffer solution. The most selective strains Cladosporium sp. CBMAI 1237 and Acremonium sp. CBMAI1676 were employed for reduction of flavanones 2a-g. The fungus Cladosporium sp. CBMAI 1237 presented yields of 72–87% with 0–64% ee cis and 0–30% ee trans with diastereoisomeric ratio (dr) from 52:48 to 64:36 (cis:trans). Whereas Acremonium sp. CBMAI 1676 resulted in 31% yield with 77–99% ee of the cis and 95–99% ee of the trans-diastereoisomers 3a-g with a dr from 54:46 to 96:4 (cis:trans). To our knowledge, this is the first report of the brominated flavon-4-ols 3e and 3f. The use of fungi, with emphasis for these marine-derived strains, is an interesting approach for enantioselective reduction of halogenated flavanones. Therefore, this strategy can be explored to obtain enantioenriched compounds with biological activities.
Synthesis and biological activity of (±)-7,3′,4′-trihydroxyhomoisoflavan and its analogs
Noshita, Toshiro,Fujita, Kentaro,Koga, Takeru,Ouchi, Hidekazu,Tai, Akihiro
, (2020/11/13)
Acetylcholinesterase (AChE) inhibitors and neurite outgrowth promoters are thought to alleviate the symptoms of degenerative brain disorders, such as Alzheimer's disease. We designed and synthesized a series of homoisoflavonoids based on the structure of natural homoisoflavan isolated from Dracaena cambodiana dragon's blood. The homoisoflavonoids were then evaluated as AChE inhibitors and neurite outgrowth promoters. The catechol structure of the homoisoflavan B rings was important for AChE inhibition, and some of the homoisoflavonoids significantly promoted neurite outgrowth induced by nerve growth factor (NGF).
B regioselective and chemoselective biotransformation of 2′-hydroxychalcone derivatives by marine-derived fungi
Nitschke, Marcia,Porto, André Luiz Meleiro,de Matos, Iara Lisboa
, (2021/08/06)
Eight fungal strains (Penicillium raistrickii CBMAI 931, Cladosporium sp. CBMAI 1237, Aspergillus sydowii CBMAI 935, Penicillium oxalicum CBMAI 1996, Penicillium citrinum CBMAI 1186, Mucor racemosus CBMAI 847, Westerdykella sp. CBMAI 1679, and Aspergillus sclerotiorum CBMAI 849) mediated the biotransformation of the 2′-hydroxychalcone 1a. The main products obtained were from hydrogenation, hydroxylation, and cyclization reactions. Penicillium raistrickii CBMAI 931 catalyzed the chemoselective reduction of 1a to produce 2′-hydroxydihydrochalcone 2a (72%) in 7 days of incubation in phosphate buffer (pH 7). Aspergillus sydowii CBMAI 935 promoted the hydroxylation of 1a to yield 2′,4-dihydroxy-dihydrochalcone 5a (c = 42%) in 7 days of incubation in phosphate buffer (pH 8). The reaction using P. citrinum CBMAI 1186 and M. racemosus CBMAI 847 presented main cyclization products in phosphate buffer (pH 8), but the reactions with these fungi did not present enantioselectivity. Marine-derived fungi were effective and versatile biocatalysts for biotransformation of the 2′-hydroxychalcones yielding different products according to the conditions and microorganism used.
Transfer Hydrogenation of Flavanones and ortho-Hydroxychalcones to 1,3-Diarylpropanols Catalyzed by CNN Pincer Ruthenium Complexes
Soto, Martín,Gotor-Fernández, Vicente,Rodríguez-Solla, Humberto,Baratta, Walter
, p. 2152 - 2157 (2021/03/03)
The transfer hydrogenation of flavanones and ortho-hydroxychalcones catalyzed by ruthenium pincer complexes RuCl(CNNPh)(disphosphine) has allowed the synthesis of ortho-hydroxy 1,3-diarypropanols in 80–88 % yield, under mild reaction conditions and short reaction times (1 h) in 2-propanol. The amount of the co-catalyst NaOiPr has been found crucial for the selective reduction of flavanones to ortho-hydroxy 1,3-diarypropanols vs. flavan-4-ols. Preliminary results show that with pincer catalysts bearing (S,R)-Josiphos, flavanone is reduced to the corresponding (S)-alcohol in moderate conversion (36 %) and up to 92 % ee.
Versatile formation of Ru(II) hydrazone complexes: Structure, theoretical studies and catalytic activity in α-alkylation
Kavitha, Venkatachalam,Murugan, Kaliyappan,Vijayapritha, Subbarayan,Viswanathamurthi, Periasamy
, (2020/09/11)
New 1-(anthracen-10-yl)methylene)-2-(benzo[d]thiazol-2-yl)hydrazine (BHA) and 1-(anthracen-10-yl)methylene)-2-(quinolin-2-yl)hydrazine (QHA) ligands were reacted with [RuHCl(CO)(E)3] (E = PPh3 or AsPh3) or [RuCl2(AsPh3)3] in a 1:1 mol ratio in chloroform-ethanol medium to synthesis new ruthenium complexes. All the new ruthenium complexes were analyzed by elemental analysis, IR, NMR (1H, 13C and 31P) spectroscopy, ESI-Mass spectrometry and single crystal XRD techniques. The single crystal XRD study reveals the octahedral geometry around the ruthenium ion. The study also shows that the ligands coordinate with the Ru metal as monoanionic bidentate N^N donors in complexes 1, 3 and 4 and as a neutral bidentate N^N donor in complex 2 by forming five or four member chelate rings. The intramolecular interactions in the crystal lattices were studied by Hirshfeld surface analysis. The results indicate that π-stacking contacts play an important role in the crystal lattices. DFT calculations were carried out to explain the solid structures of complexes 1–3. Moreover, the synthesized complexes were screened as catalysts for the α-alkylation of ketones with alcohols. The effect of various parameters, such as base, solvent, temperature, time, substituents and also catalyst loading, on the catalytic activity were analyzed. The results depict that the complex 3 was found to be an efficient catalyst for the synthesis of α-alkylation products.
Synthesis and structural characterization of facile ruthenium(II) hydrazone complexes: Efficient catalysts in α-alkylation of ketones with primary alcohols via hydrogen auto transfer
Kalaiarasi, Chinnasamy,Murugan, Kaliyappan,Vijayan, Paranthaman,Vijayapritha, Subbarayan,Viswanathamurthi, Periasamy
supporting information, (2020/08/06)
As a immersion for development of new complexes, new Ru(II) complexes (1–3) supported by benzothiazole hydrazine Schiff bases of the type [Ru(SAL-HBT)(CO)(AsPh3)2], [Ru(VAN-HBT)(CO)(AsPh3)2] and [Ru(NAP-HBT)(CO)Cl(AsPh3)2] [SAL-HBT = (salicyl((2-(benzothiazol-2yl)hydrazono)methylphenol)), VAN-HBT = 2-((2-(benzothiazol-2-yl)hydrazono)methyl)-6 methoxyphenol) and NAP-HBT = naphtyl-2-((2-(benzothiazol-2-yl)hydrazono)methyl phenol)] were synthesized. Their identities have been established by satisfactory elemental analyses, various spectroscopic techniques (IR, (1H, 13C) NMR) and also mass spectrometry. The ruthenium(II) ion exhibits a hexa coordination with distorted octahedral geometry. In complexes 1 and 2, the ligand coordinated as dianionic tridentate fashion by forming N^N donor five member and N^O donor six member chelate rings. However, in complex 3, the ligand coordinated as monoanionic bidentate fashion by forming N^N donor five-membered ring. The new ruthenium(II) carbonyl complexes were successfully applied as catalysts in α -alkylation of aliphatic and aromatic ketones with alcohols via borrowing hydrogen strategy. Various parameters such as base, solvent, temperature, time and catalyst loading on the catalytic activity were analyzed. From the results, the catalyst 1 was found to be the best catalyst for α-alkylation reaction to obtain excellent yield. The catalytic system has a broad substrate scope, which allows the synthesis of α-alkylated ketones in mild reaction conditions with low catalyst loading under air atmosphere.
Solvent-Controlled Hydrogenation of 2’-Hydroxychalcones: A Simple Solution to the Total Synthesis of Bussealins
Soto, Martín,Soengas, Raquel G.,Rodríguez-Solla, Humberto
, p. 5422 - 5431 (2020/10/06)
A solvent-controlled hydrogenation of 2’-hydroxychalcones to selectively obtain different hydrogenation products is herein reported. Thus, hydrogenation of 2’-hydroxychalcones using EtOH as solvent provided the corresponding 1,3-diarylpropanes in excellent yields. On the contrary, when the hydrogenation was performed in DCM, the corresponding dihydrochalcones were isolated. Switching the reaction solvent to n-BuOH/H2O (1:1), afforded 1,3-diarylpropanols from moderate to good yields. The methodology here reported offers a straightforward, simple and cost-effective method for the preparation of a wide variety of 2’-hydroxy-1,3-diarylpropanes derivatives, and was also applied to the preparation of natural Bussealins C and D. (Figure presented.).
