An Efficient Synthesis of Procyanidins Using Equimolar Condensation of Catechin and/or Epicatechin Catalyzed by Ytterbium Triflate

Mohri, Yoshihiro; Sagehashi, Masayoshi; Yamada, Taiji; Hattori, Yoshiyuki; Morimura, Keiji; Hamauzu, Yasunori; Kamo, Tsunashi; Hirota, Mitsuru; Makabe, Hidefumi

doi:10.3987/com-08-s(d)14

Cited by 34 publications

(4 citation statements)

References 19 publications

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“…HRESIMS m/z 579.1503 [M + H] + (calculated for C 30 H 2 6 O 12 , 579.1503). The chemical shifts and the number of proton signals in the 1 H NMR spectrum of compounds 1 matched the 1 H NMR spectrum of procyanidin B2 reported by Makabe et al [ 47 ] ( Table S3 ). The retention time, ion peak, and fragmentation pattern of compound 1 in LC-MS also matched with those of the purchased procyanidin B2 standard (Chengdu Biopurify Phytochemicals Ltd., Chengdu, China).…”

Section: Methodssupporting

confidence: 83%

Ebola Entry Inhibitors Discovered from Maesa perlarius

Tsang

Varhegyi

et al. 2022

IJMS

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Ebola virus disease (EVD), a disease caused by infection with Ebola virus (EBOV), is characterized by hemorrhagic fever and a high case fatality rate. With limited options for the treatment of EVD, anti-Ebola viral therapeutics need to be urgently developed. In this study, over 500 extracts of medicinal plants collected in the Lingnan region were tested against infection with Ebola-virus-pseudotyped particles (EBOVpp), leading to the discovery of Maesa perlarius as an anti-EBOV plant lead. The methanol extract (MPBE) of the stems of this plant showed an inhibitory effect against EBOVpp, with an IC50 value of 0.52 µg/mL, which was confirmed by testing the extract against infectious EBOV in a biosafety level 4 laboratory. The bioassay-guided fractionation of MPBE resulted in three proanthocyanidins (procyanidin B2 (1), procyanidin C1 (2), and epicatechin-(4β→8)-epicatechin-(4β→8)-epicatechin-(4β→8)-epicatechin (3)), along with two flavan-3-ols ((+)-catechin (4) and (−)-epicatechin (5)). The IC50 values of the compounds against pseudovirion-bearing EBOV-GP ranged from 0.83 to 36.0 µM, with 1 as the most potent inhibitor. The anti-EBOV activities of five synthetic derivatives together with six commercially available analogues, including EGCG ((−)-epigallocatechin-3-O-gallate (8)), were further investigated. Molecular docking analysis and binding affinity measurement suggested the EBOV glycoprotein could be a potential molecular target for 1 and its related compounds.

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Section: Methodssupporting

confidence: 83%

Ebola Entry Inhibitors Discovered from Maesa perlarius

Tsang

Varhegyi

et al. 2022

IJMS

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“…Dimers 1 , 4 , and 7 were identified as procyanidin B1, procyanidin B3, and procyanidin B2, respectively. Their 1 H NMR, 13 C NMR, and electronic circular dichroism (ECD) spectra closely matched the reported data. , Compounds 2 , 3 , 5 , and 6 were found to be new PAC dimers containing the rare ent -catechin or ent -epicatechin constituent units. The 1 H and 13 C NMR assignment of all new compounds 2 , 3 , 5 , 6 , and 9 (obtained via HiFSA) are presented in Tables – .…”

Section: Results and Discussionmentioning

confidence: 99%

Proanthocyanidin Dimers and Trimers from Vitis vinifera Provide Diverse Structural Motifs for the Evaluation of Dentin Biomodification

et al. 2019

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Aimed at exploring the dentin biomodification potential of proanthocyanidins (PACs) for the development of dental biomaterials, this study reports the phytochemical and dental evaluation of nine B-type PACs from grape seed extract (GSE). Out of seven isolated dimers (1−7), four new compounds (2, 3, 5, and 6) involved relatively rare entcatechin or ent-epicatechin monomeric flavan-3-ol units. Lowtemperature NMR analyses conducted along with phloroglucinolysis and electronic circular dichroism enabled unequivocal structural characterization and stereochemical assignment. Additionally, one known (8) and one new (9) B-type trimer were characterized. Differential 13 C NMR chemical shifts (Δδ) were used to determine the absolute configuration of 9, relative to the dimers 1 and 2 as the possible constituent subunits. Compared to the dimers, the trimers showed superior dentin biomodification properties. The dimers, 1−7, exhibited pronounced differences in their collagenase inhibitory activity, while enhancing dentin stiffness comparably. This suggests that PAC structural features such as the degree of polymerization, relative and absolute configuration have a differential influence on enhancement of dentin biomechanical and biostability. As mechanical enhancement to dentin and resistance to proteolytic biodegradation are both essential properties functional and stable dentin substrate, the structurally closely related PACs suggest a new metric, the dentin biomodification potential (DBMP) that may rationalize both properties.

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“…However, in many cases, proanthocyanidins are obtained as a mixture of various analogs, which makes purification of each compound difficult. After an elegant contribution by Kozikowski et al [5,6,7], a large number of syntheses of oligomeric catechin and epicatechin derivatives were reported [8,9,10,11,12,13,14,15]. We have also developed and reported a simple, versatile, and stereoselective methods for synthesizing procyanidin oligomers using (−)-epicatechin ( 2 ) and (+)-catechin ( 3 ) (Figure 1) [16,17,18,19,20,21,22,23,24,25,26,27,28].…”

Section: Introductionmentioning

confidence: 99%

Inhibitory Activity of Synthesized Acetylated Procyanidin B1 Analogs against HeLa S3 Cells Proliferation

et al. 2014

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Proanthocyanidins, also known as condensed tannins and/or oligomeric flavonoids, occur in many edible plants and have various interesting biological activities. Previously, we reported a synthetic method for the preparation of various procyanidins in pure form and described their biological activities. Here, we describe the synthesis of procyanidin B 1 acetylated analogs and discuss their inhibition activities against HeLa S3 cell proliferation. Surprisingly, the lower-unit acetylated procyanidin B 1 strongly inhibited the proliferation of HeLa S3 cells. This molecule showed much stronger inhibitory activity than did epigallocatechin-3-O-gallate (EGCG), green tea polyphenol, and dimeric compounds that included EGCG as a unit. This result suggests that the phenolic hydroxyl groups of the upper-units in flavan-3-ols are important for their inhibitory activity against cancer cell proliferation and that a hydrophobic lower unit dimer enhances this activity.

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An Efficient Synthesis of Procyanidins Using Equimolar Condensation of Catechin and/or Epicatechin Catalyzed by Ytterbium Triflate

Abstract: -Stereoselective synthesis of catechin and epicatechin dimers under intermolecular condensation of equimolar amount of catechin derivatives catalyzed by Yb(OTf)

Cited by 34 publications

References 19 publications

Ebola Entry Inhibitors Discovered from Maesa perlarius

Ebola Entry Inhibitors Discovered from Maesa perlarius

Proanthocyanidin Dimers and Trimers from Vitis vinifera Provide Diverse Structural Motifs for the Evaluation of Dentin Biomodification

Inhibitory Activity of Synthesized Acetylated Procyanidin B1 Analogs against HeLa S3 Cells Proliferation

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