Xanthone dimers: a compound family which is both common and privileged

Wezeman, Tim; Bräse, Stefan; Masters, Kye-Simeon

doi:10.1039/c4np00050a

Cited by 162 publications

(144 citation statements)

References 163 publications

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“…Meanwhile, the dimers were regularly formed by unit B with diverse path A units. These patterned dimerisations together with the specific monomeric modifications, indicated the enzymatic nature of these reactions, rather than the radical coupling2425.…”

Section: Resultsmentioning

confidence: 96%

Unusual dimeric tetrahydroxanthone derivatives from Aspergillus lentulus and the determination of their axial chiralities

Yang

Wang

et al. 2016

Sci Rep

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The research on secondary metabolites of Aspergillus lentulus afforded eight unusual heterodimeric tetrahydroxanthone derivatives, lentulins A−H (2−9), along with the known compound neosartorin (1). Compounds 1−6 exhibited potent antimicrobial activities especially against methicillin-resistant Staphylococci. Their absolute configurations, particularly the axial chiralities, were unambiguously demonstrated by a combination of electronic circular dichroism (ECD), Rh2(OCOCF3)4-induced ECD experiments, modified Mosher methods, and chemical conversions. Interestingly, compounds 1–4 were the first samples of atropisomers within the dimeric tetrahydroxanthone class. Further investigation of the relationships between their axial chiralities and ECD Cotton effects led to the proposal of a specific CD Exciton Chirality rule to determine the axial chiralities in dimeric tetrahydroxanthones and their derivatives.

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Section: Resultsmentioning

confidence: 96%

Unusual dimeric tetrahydroxanthone derivatives from Aspergillus lentulus and the determination of their axial chiralities

Yang

Wang

et al. 2016

Sci Rep

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“…31 Anticancer activities were recorded for some derivatives against several tumor cell lines, where secalonic acid D is the most active. 32 Concerning antimicrobial activities, blennolides 21 and dicerandrols 33 inhibited several pathogens. So far, only paecilin C was evaluated for its antibacterial potential, however, showed no activity.…”

Section: Antimicrobial Assaysmentioning

confidence: 99%

Antifungal Polyketides and Other Compounds from Amazonian Endophytic Talaromyces Fungi

Silva

Souza

Bianco

et al. 2017

J. Braz. Chem. Soc.

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The continuous search for biologically active compound candidates pushes the pursuit of new substances produced by diverse organisms. Endophytic fungi are known as a promising source of metabolites with several biological activities. Based on the rich Amazonian biodiversity and the chemical potential of microbial sources, three Talaromyces strains, all major endophytes from their respective host plants, were studied aiming at the isolation of biologically active secondary metabolites. Through classical chromatographic approaches, 13 compounds were isolated from the antimicrobial extracts of the studied strains. From these, polyketides, steroids, anhydrides, and phenolic compounds were identified. Among them, two previously undescribed compounds were elucidated based on spectroscopic and spectrometric methods, a homodimer chromanone and a maleic anhydride methyl ester. The antimicrobial activity against a panel of pathogenic microorganisms from extracts, fractions, and isolated compounds was evaluated.

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“…Together, these examples illustrate how structurally related but functionally distinct compounds can result from the diversification of tailoring genes within a conserved biosynthetic gene cluster. Many anthraquinone and xanthone homo-and heterodimers have been isolated from natural producers (5,13) or genetically modified Aspergillus species expressing genes related to monodictyphenone and atrochrysone biosynthesis (7,14). Although dimerization of anthraquinone Significance Anthraquinones are potent secondary metabolites produced by many fungi and plants used in traditional Chinese and Indian medicine.…”

mentioning

confidence: 99%

Elucidation of cladofulvin biosynthesis reveals a cytochrome P450 monooxygenase required for anthraquinone dimerization

Griffiths

Mesarich

Saccomanno

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

161

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Anthraquinones are a large family of secondary metabolites (SMs) that are extensively studied for their diverse biological activities. These activities are determined by functional group decorations and the formation of dimers from anthraquinone monomers. Despite their numerous medicinal qualities, very few anthraquinone biosynthetic pathways have been elucidated so far, including the enzymatic dimerization steps. In this study, we report the elucidation of the biosynthesis of cladofulvin, an asymmetrical homodimer of nataloe-emodin produced by the fungus Cladosporium fulvum. A gene cluster of 10 genes controls cladofulvin biosynthesis, which begins with the production of atrochrysone carboxylic acid by the polyketide synthase ClaG and the β-lactamase ClaF. This compound is decarboxylated by ClaH to yield emodin, which is then converted to chrysophanol hydroquinone by the reductase ClaC and the dehydratase ClaB. We show that the predicted cytochrome P450 ClaM catalyzes the dimerization of nataloe-emodin to cladofulvin. Remarkably, such dimerization dramatically increases nataloe-emodin cytotoxicity against mammalian cell lines. These findings shed light on the enzymatic mechanisms involved in anthraquinone dimerization. Future characterization of the ClaM enzyme should facilitate engineering the biosynthesis of novel, potent, dimeric anthraquinones and structurally related compound families.secondary metabolism | gene cluster | cytoxicity | emodin | nataloe-emodin

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Xanthone dimers: a compound family which is both common and privileged

Cited by 162 publications

References 163 publications

Unusual dimeric tetrahydroxanthone derivatives from Aspergillus lentulus and the determination of their axial chiralities

Unusual dimeric tetrahydroxanthone derivatives from Aspergillus lentulus and the determination of their axial chiralities

Antifungal Polyketides and Other Compounds from Amazonian Endophytic Talaromyces Fungi

Elucidation of cladofulvin biosynthesis reveals a cytochrome P450 monooxygenase required for anthraquinone dimerization

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