Hopane-Type Triterpenes and Binaphthopyrones from the Scale Insect Pathogenic Fungus <i>Aschersonia paraphysata</i> BCC 11964

Isaka, Masahiko; Yangchum, Arunrat; Rachtawee, Pranee; Komwijit, Somjit; Lutthisungneon, Apisara

doi:10.1021/np1000363

Cited by 22 publications

(21 citation statements)

References 26 publications

(57 reference statements)

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“…The CD Exciton Chirality method has been applied to some axially chiral determinations before, such as those of binaphthyl, biarylic dihydronaphthopyranone3031, and bis(naphtho- γ -pyrone)32. However, a very few exceptions were reported due to their complicated chromophores and non-negligible intense magnetic transition dipole moments3334.…”

Section: Resultsmentioning

confidence: 99%

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: 99%

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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“…This broad array of sequences were more closely rooted with bacterial SHC orthologues as noted previously (Frickey and Kannenberg, 2009), suggesting that they encode for triterpenes with hopene-type ring systems. Indeed some of the fungi in these clades, for example, Aschersonia species, have been reported to produce hopane-type terpenoids (Isaka et al, 2009(Isaka et al, , 2010.…”

Section: Phylogenetic Analysis Of Enfumafungin Synthase (Efua)mentioning

confidence: 99%

Enfumafungin synthase represents a novel lineage of fungal triterpene cyclases

Kuhnert

et al. 2018

Environmental Microbiology

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Summary Enfumafungin is a glycosylated fernene-type triterpenoid produced by the fungus Hormonema carpetanum. Its potent antifungal activity, mediated by its interaction with β−1,3-glucan synthase and the fungal cell wall, has led to its development into the semi-synthetic clinical candidate, ibrexafungerp (=SCY-078). We report on the preliminary identification of the enfumafungin biosynthetic gene cluster (BGC) based on genome sequencing, phylogenetic reconstruction, gene disruption, and cDNA sequencing studies. Enfumafungin synthase (efuA) consists of a terpene cyclase domain (TC) fused to a glycosyltransferase (GT) domain and thus represents a novel multifunctional enzyme. Moreover, the TC domain bears a phylogenetic relationship to bacterial squalene–hopene cyclases (SHC) and includes a typical DXDD motif within the active centre suggesting that efuA evolved from SHCs. Phylogenetic reconstruction of the GT domain indicated that this portion of the fusion gene originated from fungal sterol GTs. Eleven genes flanking efuA are putatively involved in the biosynthesis, regulation, transport and self-resistance of enfumafungin and include an acetyltransferase, three P450 monooxygenases, a dehydrogenase, a desaturase and a reductase. A hypothetical scheme for enfumafungin assembly is proposed in which the E-ring is oxidatively cleaved to yield the four-ring system of enfumafungin. EfuA represents the first member of a widespread lineage of fungal SHCs.

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“…Compound 162 are antimalarial, antifungal and antibacterial [53]. Another insect pathogen Aschersonia paraphysata BCC 11964 produces aschernaphthopyrones A (164, Scheme 10) and B (165, Scheme 10), two new biarylic dihydronaphthopyrones [54]. …”

Section: Quinonesmentioning

confidence: 99%