Perrottetins E, F, and G from (liverwort)--isolation, structure determination, and synthesis of perrottetin e

Toyota, Masao; Tori, Motoo; Takikawa, Keiko; Shiobara, Yoshinori; Kodama, Masashi; Asakawa, Yoshinori

doi:10.1016/s0040-4039(00)95135-9

Cited by 58 publications

(26 citation statements)

References 3 publications

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“…This family of natural molecules has exhibited anticancer [16], antioxidant [17], antiplatelet [18], and tyrosinase inhibitory [11] activities. However, limited availability and poor structural diversity among natural sources has hindered detailed pharmacological studies.…”

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confidence: 99%

Biocatalytic Production of Acyclic Bis[bibenzyls] from Dihydroresveratrol by Crude Momordica charantia Peroxidase

Xie¹,

Yuan²,

Qu³

et al. 2009

Chemistry & Biodiversity

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Biotransformation of dihydroresveratrol by crude Momordica charantia peroxidase provided six new acyclic bis[bibenzyls] 1-6. Their structures were established on the basis of NMR and MS analyses as C-C, C-O-C, and C-CH(2)-C dimers of dihydroresveratrol. Compounds 1-6 were tested for antiproliferative activity against human prostate cancer PC3 cell line in vitro, and 2 and 6 were found to be more potent than the parent compound.

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confidence: 99%

Biocatalytic Production of Acyclic Bis[bibenzyls] from Dihydroresveratrol by Crude Momordica charantia Peroxidase

Xie¹,

Yuan²,

Qu³

et al. 2009

Chemistry & Biodiversity

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“…Synthesis of C 70 Mono-Crown Ether Conjugates Featuring Twelve and Two O×Clock Addition Patterns. Bis-malonate 6 with a syn-substituted DB18C6 tether was previously obtained only as an unseparable 1 : 1 mixture together with anti-isomer 5 [29a,b] [43]. Synthesis of pure 6 started from 3,4-dihydroxybenzaldehyde 8, which was regioselectively benzyl-protected to give 9 (Scheme 2) [43].…”

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confidence: 99%

“…Bis-malonate 6 with a syn-substituted DB18C6 tether was previously obtained only as an unseparable 1 : 1 mixture together with anti-isomer 5 [29a,b] [43]. Synthesis of pure 6 started from 3,4-dihydroxybenzaldehyde 8, which was regioselectively benzyl-protected to give 9 (Scheme 2) [43]. Minor amounts of the other protected regioisomer and dibenzylated side product were removed by column chromatography.…”

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confidence: 99%

Supramolecular Fullerene Chemistry: A Comprehensive Study of Cyclophane-Type Mono- and Bis-Crown Ether Conjugates of C70

Eis

Seiler

Muslinkina

et al. 2002

HCA

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A Corun ƒ a Dedicated to Professor Friedrich Bickelhaupt on the occasion of his 70th birthday.The covalently templated bis-functionalization of C 70 , employing bis-malonate 5 tethered by an antidisubstituted dibenzo [18]crown-6 (DB18C6) ether, proceeds with complete regiospecificity and provides two diastereoisomeric pairs of enantiomeric C 70 crown ether conjugates, (AE)-7a and (AE)-7b, featuring a five o×clock bis-addition pattern that is disfavored in sequential transformations (Scheme 1). The identity of (AE)-7a was revealed by X-ray crystal-structure analysis (Fig. 6). With bis-malonate 6 containing a syn-disubstituted DB18C6 tether, the regioselectivity of the macrocylization via double Bingel cyclopropanation changed completely, affording two constitutionally isomeric C 70 crown ether conjugates in a ca. 1 : 1 ratio featuring the twelve (16) and two o×clock ((AE)-15) addition patterns, respectively (Scheme 3). The X-ray crystal-structure analysis of the twelve o×clock bis-adduct 16 revealed that a H 2 O molecule was included in the crown ether cavity (Figs. 7 and 8). Two sequential Bingel macrocyclizations, first with anti-DB18C6-tethered (5) and subsequently with syn-DB18C6-tethered (6) bis-malonates, provided access to the first fullerene bis-crown ether conjugates. The two diastereoisomeric pairs of enantiomers (AE)-28a and (AE)-28b were formed in high yield and with complete regioselectivity (Scheme 9). The cation-binding properties of all C 70 crown-ether conjugates were determined with the help of ion-selective electrodes (ISEs). Mono-crown ether conjugates form stable 1 : 1 complexes with alkali-metal ions, whereas the tetrakis-adducts of C 70 , featuring two covalently attached crown ethers, form stable 1 : 1 and 1 : 2 host-guest complexes ( Table 2). Comparative studies showed that the conformation of the DB18C6 ionophore imposed by the macrocyclic bridging to the fullerene is not particularly favorable for strong association. Reference compound (AE)-22 (Scheme 4), in which the DB18C6 moiety is attached to the C 70 sphere by a single bridge only and, therefore, possesses higher conformational flexibility, binds K and Na ions better by factors of 2 and 20, respectively. Electrochemical studies demonstrate that cation complexation at the crown ether site causes significant anodic shifts of the first reduction potential of the appended fullerene (Table 3). In case of the C 70 mono-crown ether conjugates featuring a five o×clock functionalization pattern, addition of 1 equiv. of KPF 6 caused an anodic shift of the first reduction wave in the cyclic voltammogram (CV) by 70 to 80 mV, which is the result of the electrostatic effect of the K ion bound closely to the fullerene core (Fig. 14). Addition of 2 equiv. of K ions to C 70 bis-crown ether conjugates resulted in the observation of only one redox couple, whose potential is anodically shifted by 170 mV with respect to the corresponding wave in the absence of the salt (Fig. 16). The synthesis and characterization of novel tris-and tetrakis-adducts of ...

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“…(5g) [59], perrottetin E (compound 8) Fig. (5h) [60], plagiochin E (compound 9) Fig. (5i) [61] and riccardin B (compound 10) Fig.…”

Section: Other Antifungal Compounds Previously Reportedmentioning

confidence: 99%

Recent Trends in Plant-Derived Antifungal Agents

Shahid

Shahzad²,

Tripathi³

et al. 2009

AIAMC

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Recent years have witnessed emergence of resistance to azoles and other antifungal compounds. Moreover, the existing antifungal compounds for the contemporary clinicians are limited in numbers as opposed to available antibacterial compounds. Hence there is a real need to search for newer compounds with potential antifungal activity. In this review, the potential of medicinal plant species to yield newer antifungal agents would be illustrated with an emphasis on compounds discovered in recent years. Some of the issues pertinent to this area, including their botanical, medicinal, and available spectroscopic data, will briefly be reviewed and it is hoped that this would definitely stimulate for their discussions and researches on this important aspect including the mechanism of actions of these recently discovered compounds.

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Perrottetins E, F, and G from (liverwort)--isolation, structure determination, and synthesis of perrottetin e

Cited by 58 publications

References 3 publications

Biocatalytic Production of Acyclic Bis[bibenzyls] from Dihydroresveratrol by Crude Momordica charantia Peroxidase

Biocatalytic Production of Acyclic Bis[bibenzyls] from Dihydroresveratrol by Crude Momordica charantia Peroxidase

Supramolecular Fullerene Chemistry: A Comprehensive Study of Cyclophane-Type Mono- and Bis-Crown Ether Conjugates of C70

Recent Trends in Plant-Derived Antifungal Agents

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