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The Jurassic relict Royal fern, Osmunda regalis L., is widely distributed across temperate zones in the Northern and Southern hemispheres. Even though this species has been utilised for centuries as a medicinal plant, its phytochemical composition mainly remains unknown. As part of our ongoing research to identify potential lead compounds for future anticancer drugs, 17 natural products were characterised from the aerial parts of Osmunda regalis L. Fifteen of these compounds were identified in this species for the first time, including the six previously undescribed compounds kaempferol 3-O-(2"-O-(2"'-α-rhamnopyranosyl)-β-glucopyranosyl)-β-glucopyranoside, quercetin 3-O-(2"-O-(2"'-α-rhamnopyranosyl)-β-glucopyranosyl)-β-glucopyranoside, kaempferol 3-O-(2"-O-(2"'-α-rhamnopyranosyl-6"'-O-(E)-caffeoyl-)-β-glucopyranosyl)-β-glucopyranoside, 3-methoxy-5-hydroxy-4-olide, 4-hydroxy-3-(3'-hydroxy-4'-(hydroxyethyl)-oxotetrafuranone-5-methyl tetrahydropyranone, and 4-O-(5-hydroxy-4-oxohexanoyl) osmundalactone. The molecular structures were determined by combining several 1D and 2D NMR experiments, circular dichroism spectroscopy, and HRMS. Determination of cytotoxicity against AML MOLM-13, H9c2, and NRK cell lines showed that two isolated lactones exhibited significant cytotoxic activity. [ABSTRACT FROM AUTHOR]

[beta]-acyloxy [alpha],[beta]-unsaturated acetylenic ketones have reacted with organocuprate reagents and have undergone cyclization followed by dehydration to give substituted furans as the final products. Tri- and tetra-substituted furans are obtained with regiochemical control and best yields are obtained when the reactions are performed around -60 [degree] C with substrates and cuprates containing sterically demanding substituents.

A number of 3-(4,4,5,5-tetraethoxy-1-hydroxy-1-arylpent-2-ynyl)quinoxalin-2(1 H)-ones, obtained by reacting the lithium acetylide of 3,3,4,4-tetraethoxybut-1-yne (TEB) with 3-aroylquinoxalin-2(1 H)-ones, appeared to undergo in the 5- exo-Dig manner when heated at reflux in acidic, aqueous THF. In each case, the products were the corresponding ( E)-1,1-diethoxy-3-(3-hydroxy-3-arylfuro[2,3- b]quinoxalin-2(3 H)-ylidene)propan-2-ones and 1,1-diethoxy-3-hydroxy-3-(3-arylfuro[2,3- b]quinoxalin-2-yl)propan-2-one, which were isolated in an approximate ratio of 2:1 in high total yield. Irrespective of the structure of the aryl group, both compounds were stable solids when kept in a refridgerator (3 °C), but when the latter product was dissolved in chloroform and stored at room temperature, it rearranged smoothly and quantitatively to the former compound within a few days. [ABSTRACT FROM AUTHOR]

3,3,4,4-Tetraethoxybut-1-yne acetylide (TEB-) reacted with several epoxides under a variety of conditions. When the acetylide counterion was lithium, nothing happened in the absence of ammonia and HMPA, but reaction of TEBLi with a mixture of oxirane and BF3 (oxirane/BF3 addition to the acetylide) followed by hydrolysis gave the expected homopropargylic alcohols in about 80% yield. When the counterion was MgBr+, oxirane-to-aldehyde rearrangement took place before the acetylide reacted and gave propargylic alcohols in good yields in all cases except one; the only exception was ethylene oxide, which gave the homopropargylic alcohol in 70% yield. [ABSTRACT FROM AUTHOR]

Increasing use of the chitin synthesis inhibitor diflubenzuron against the ectoparasitic salmon louse Lepeophtheirus salmonis in marine aquaculture has raised concerns over its environmental impacts. This study evaluated how diflubenzuron affects Atlantic cod Gadus morhua, a fish species often found near Atlantic salmon Salmo salar farms, focusing on uptake kinetics and hepatic transcriptional responses. Two experiments were conducted, one time-series trial in which the fish were given a daily dose (3 mg kg-1 fish) of diflubenzuron for 14 d followed by a 3 wk depuration period, and one dose-response trial with increasing concentrations (3, 10 and 50 mg kg-1 fish). The highest diflubenzuron concentrations were found in the liver at Day 15. No detectable levels of diflubenzuron were found in liver or muscle 3 wk after the end of the treatment. At the molecular level, small effects of diflubenzuron treatment on gene transcription were observed. In the time-series experiment, the strongest effects were seen at Day 8, with 2 transcripts being upregulated (bclx2 and cpt1a) and 8 transcripts being downregulated (gstp1, gstm1, gstt1, ugt1a, nat2, cat, p53 and slc16a9a). Five transcripts (cyp3a, cpt1a, ptgs2, elovl5 and mapk1) responded significantly to diflubenzuron exposure in the dose-response experiment. This study shows that diflubenzuron can be taken up by Atlantic cod, that it is rapidly cleared from the body and that when present this pharmaceutical causes only small effects on the expression of genes involved in detoxification pathways. Taken together, our data suggest that accumulated diflubenzuron at the levels studied would have a relatively small effect on wild Atlantic cod.