Vibralactone Z4, the first chain-like vibralactone derivative from cultures of the basidiomycete Boreostereum vibrans

The first chain-Like vibralactone derivative, vibralactone Z₄ (1), together with three known ones (2–4), were isolated from cultures of the basidiomycete Boreostereum vibrans. Vibralactone Z₄ (1) is likely to be a key intermediate from 3 to 4 in their biosynthetic pathway. It showed a weak cytotoxicity to human cancer cell line SW480 (IC₅₀ 29.2?±?1.38?μM).     

Vibralactone: a lipase inhibitor with an unusual fused beta-lactone produced by cultures of the basidiomycete Boreostereum vibrans

The structure and absolute configuration of vibralactone (1) from the cultures of the Basidiomycete Boreostereum vibrans were established by spectroscopic methods and computational methods. Vibralactone, an unusual fused beta-lactone-type metabolite, was found to inhibit pancreatic lipase with an IC50 of 0.4 microg/mL. [structure: see text]     

A Monooxygenase from Boreostereum vibrans Catalyzes Oxidative Decarboxylation in a Divergent Vibralactone Biosynthesis Pathway

The oxidative decarboxylation of prenyl 4‐hydroxybenzoate to prenylhydroquinone has been frequently proposed for the biosynthesis of prenylated (hydro)quinone derivates (sometimes meroterpenoids), yet no corresponding genes or enzymes have so far been reported. A FAD‐binding monooxygenase (VibMO1) was identified that converts prenyl 4‐hydroxybenzoate into prenylhydroquinone and is likely involved in the biosynthesis of vibralactones and other meroterpenoids in the basidiomycete Boreostereum vibrans. Feeding of 3‐allyl‐4‐hydroxybenzylalcohol, an analogue of the vibralactone pathway intermediate 3‐prenyl‐4‐hydroxybenzylalcohol, generated 20 analogues with different scaffolds. This demonstrated divergent pathways to skeletally distinct compounds initiating from a single precursor, thus providing the first insight into a novel biosynthetic pathway for 3‐substituted γ‐butyrolactones from a shikimate origin.     

Two new compounds from cultures of the basidiomycete Antrodiella albocinnamomea

A new linear triterpene (1), and a new sesquiterpene (2), together with a known compound methyl indole-3-carboxylate (3) were isolated from the crude extract of Antrodiella albocinnamomea. The structures of the new compounds 1–2 were determined by comprehensive spectroscopic analysis. Compound 1 exhibited signi?cant inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ value of 1.0 μg/mL.     

One new sterpurane sesquiterpene from cultures of the basidiomycete Pholiota nameko

Abstract

One new sterpurane sesquiterpene (1), named (3R,6S,7S,8R,10S)-3,7,14-trihydroxy-1-sterpurene was isolated from cultures of the basidiomycete Pholiota nameko. The structure of new compound was elucidated by extensive spectroscopic. Additionally, a single crystal X-ray diffraction not only confirmed the structure, but also determined the absolute configuration of the new compound. The compound was evaluated for cytotoxicity against five human cancer cell lines, but no significant cytotoxicity were found (IC₅₀ values > 40?μM).     

Daedaleanols A and B,two new sesquiterpenes from cultures of the basidiomycete Daedalea incana

Two new sesquiterpenes, daedaleanols A (1) and B (2), together with three known sesquiterpenes (3–5), were isolated from cultures of the basidiomycete Daedalea incana. Their structures were elucidated on the basis of extensive spectroscopic means. All compounds were tested for their cytotoxicities against three human cancer cell lines.     

Highly unsaturated pyranone derivatives from the basidiomycete Junghuhnianitida

Four new highly unsaturated pyranone derivatives A–D (1–4), together with one known compound 5 (−)-nitidon were isolated from cultures of the fungus Junghuhnianitida. Planar structures of the new compounds were elucidated on the basis of extensive NMR spectroscopic and mass spectrometric analyses. Absolute configurations of the new compounds were determined on the basis of biosynthetic considerations and quantum chemistry theory. Compound 1 exhibited almost the same cytotoxic activities as cis-platin.     

Lanostane triterpenoids from cultivated fruiting bodies of the basidiomycete Ganoderma australe

A new lanostane triterpene (1), together with three known compounds (2–4), were isolated from cultivated fruiting bodies of the basidiomycete Ganoderma australe. The structure was elucidated on the basis of NMR spectroscopic and mass spectrometry data. The olefinic geometry of methyl australate (2) was revised from 20(22)Z to 20(22)E. These compounds (1–4) were different from the lanostanes isolated from mycelial cultures of the same strain source.     

Bioactive metabolites from biotransformation of paeonol by the white-rot basidiomycete Coriolus versicolor

Biotransformation of paeonol (1) with the white-rot basidiomycete Coriolus versicolor afforded two metabolites, 2,4-dihydroxyacetophenone (2) and 2,5-dihydroxy-4-methoxyacetophenone (3), which were identified by spectroscopic methods. Compound 3 showed higher antioxidative, antibacterial, antifungal activities than 1 or 2. The results demonstrate for the first time that C. versicolor has the capacities to catalyze hydroxylation and demethylation reactions on the aromatic compound.     

The structure of grifolin, an antibiotic from a basidiomycete

Structure of grifolin was deduced as 2-trans,trans-farnesyl-5-methylresorcinol (I).     

Pteratides I-IV, new cytotoxic cyclodepsipeptides from the Malaysian basidiomycete Pterula sp

Four new cyclodepsipeptides, pteratides I-IV (1-4), have been isolated from the extract of a Pterula species collected from a Malaysian tropical forest. Homonuclear and heteronuclear 2D NMR techniques as well as MS fragmentation experiments, in combination with methanolysis, determined the gross structures of the peptides and showed that pteratides I and II each contained the nonproteinogenic amino acid 4-methylproline. The absolute configurations of the amino acids in pteratides I-IV were established using Marfey's method. Pteratides I and II are each potently cytotoxic against the P388 murine leukemia cell line (IC50 values of 41 and 40 nM, respectively). Pteratides III and IV show weaker, but still notable, activity with IC50 values of 7.4 and 2.9 microM, respectively.     

Two novel norsesquiterpene peroxides from basidiomycete Steccherinum ochraceum

Two novel 3-nor-methyl-chamigrane sesquiterpene peroxides, named steperoxide A (1) and B (2), have been isolated from basidiomycete Steccherinum ochraceum. This is the first report on the isolation of chamigrane sesquiterpene from higher fungi. The structures of 1 and 2 were established on the basis of spectroscopic data and single-crystal X-ray analysis.     

Synthesis of (+/-)- and (-)-vibralactone and vibralactone C

Mander reductive alkylation of methyl 2-methoxybenzoate with prenyl bromide and hydrolysis of the enol ether afforded methyl 6-oxo-1-prenyl-2-cyclohexenecarboxylate. This was converted in five steps (reduction of the ketone, saponification, iodolactonization, ozonolysis, and intramolecular aldol reaction) to a spiro lactone cyclopentenal. An efficient first synthesis of (+/-)-vibralactone was completed by retro-iodolactonization with activated Zn, formation of the beta-lactone (vibralactone C), and reduction of the aldehyde. Except for the novel use of an iodolactone to protect both the prenyl double bond and carboxylic acid, no protecting groups were used. A similar sequence starting with asymmetric reductive alkylation of the (2S)-2-methoxymethoxymethylpyrrolidine amide of 2-methoxybenzoic acid with prenyl bromide afforded (-)-vibralactone confirming the absolute stereochemical assignment that was based on computational methods.     

Chromanone Derivatives from the Pericarps of Calophyllum polyanthum

Three new chromanone derivatives, calopolyanic acid ( 1 ), isocalopolyanic acid ( 2 ), and isorecedensic acid ( 3 ), were isolated from the pericarps of Calophyllum polyanthum Wall . ex Choisy , along with seven known compounds, apetalic acid, blancoic acid, chapelieric acid, methyl isoapetalate, isoapetalic acid, isocalolongic acid, and recedensic acid. All of these compounds were reported from C. polyanthum for the first time. The structures of 1 – 3 were elucidated by spectroscopic methods.     

Cycloheximide Derivatives from the Fruits of Dipteronia dyeriana

The phytochemical investigation of Dipteronia dyeriana (Aceraceae) resulted in the isolation and identification of three new cycloheximide derivatives: dipteronines A–C ( 1 – 3 ). Their structures were elucidated based on the 1D‐ and 2D‐NMR spectra. Dipteronine A ( 1 ) is the first example of a 10,11‐secocycloheximide. Cytotoxic and antifungal activities of these isolates were also evaluated.     

Benzofuran Derivatives from Ligularia Stenocephala

Four new benzofuran derivatives were isolated from the roots of Ligularia stenocephala; they were named as ligustenin A ( 1 ), B ( 2 ), C ( 3 ) and D ( 4 ), and the structures were established by spectroscopic methods including 2D NMR techniques. Ligustenin A (1) was found to exhibit potent anti‐tumor activity against HL‐60 (human leukemia cells), Bel‐7402 (human hepatoma cells) and HO‐8910 (human ovarian neoplasm cells) with IC₅₀ values of 18.6, 27.6 and 57.5 μM, respectively.     

Cyclohexanecarboxylic-Acid Derivatives from Psiadia trinervia

From a MeOH extra of Psiadia trinervia, seven phenolic compounds were isolated by gel filtration and reversed-phase chromatography. Six of them are known compounds, namely 3,4-di-O-caffeoylquinic acid ( 2 ), 3,5-di-O-caffeoylquinic acid ( 3 ), caffeic acid, and three 3-methoxyflavonoids. Compound 1 is a 3,4-di-O-caffeoyl derviative of (1S,3R,4R,5R)-1,3,4, 5-tetrahydroxycyclohexanecarboxylic acid, a novel steroisomer of (?)-quinic acid. Following hydrolytic treatment of the MeOH extract, ethyl 3-O-caffeoylquinate ( 4 ), ethyl 3,4-di-O-caffeoylquinate ( 5 ), and ethyl 3,5-O-caffeoylquinate ( 6 ) were isolated. The latter three compounds are artifacts. The configuration of 1-3 was established by NMR and CD (exciton chirality method).     

Bisresorcinol Derivatives from Grevillea glauca

Seven new and three known bisresorcinols, grevirobstol A (=5,5′‐((6Z,9Z)‐hexadeca‐6,9‐diene‐1,16‐diyl)bisresorcinol; 8 ), 5,5′‐[(8Z)‐hexadec‐8‐ene‐1,16‐diyl]bisresorcinol ( 9 ), and 2‐methyl‐5,5′‐[8Z)‐hexadec‐8‐ene‐1,16‐diyl]bisresorcinol ( 10 ) were isolated from the stems of Grevillea glauca. The new compounds were identified on the basis of spectroscopic data as (Z)‐6,7‐didehydroglaucone A ( 1 ), glaucones A and B ( 2 and 3 , resp.), 2‐(3‐hydroxyisopentyl)bisnorstriatol ( 4 ), 2‐(3‐methylbut‐2‐en‐1‐yl)bisnorstriatol ( 5 ), 2′‐methylgrebustol A ( 6 ), and glaucane ( 7 ).