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Degradation of plant biomass, comprised of cellulose and polyaromatic lignin, is promoted by light. Here, the authors show that light promotes lignin-catalyzed generation of hydrogen peroxide, which is used by redox enzymes to degrade cellulose.

The alkyne zipper reaction is an internal-to-terminal alkyne isomerization reaction with many interesting applications in synthetic chemistry, as it constitutes an efficient means of achieving acetylene functionalization. A review of its applications in synthesis processes is presented in this paper, with a brief overview of the mechanistic features of the alkyne zipper reaction, as well as a brief overview of its future potential.

Det finnes i dag mange studier for oppfølging og veiledning av ph.d.-studenter, men tilsvarende få for mastergradsstudenter, til tross for at den store majoriteten av studenter avslutter utdanningen med nettopp mastergraden. Kartlegging viste at mange studenter er usikre på sin egen rolle i arbeidet med masteroppgaven. I tillegg har mange lav motivasjon og mestringstro. Vi har sett på hvordan veiledning og rammer kan gjøres bedre med små og enkle grep, blant annet ved å oppmuntre studentene til å jobbe med laboratoriearbeid, teori og skriving parallelt. De viktigste tiltakene som ble gjennomført, er aktiv bruk av læringsplattformen, bedre opplæring innen litteratursøk og mer øvelse i muntlig og skriftlig formidling. Resultatene viser at studentene ble mer drevet av indre motivasjon, føler mer eierskap og har økt mestringstro etter at tiltakene ble innført.

Abstract Thioridazine, a well-known antipsychotic drug, has shown promising effects on several bacterial strains (including Mycobacterium tuberculosis and methicillin-resistant Staphylococcus aureus). Suppressive effects towards selected cancer cell-lines have also been reported. However, due to adverse effects, the compound is no longer in use for the primary indication. More recent research has demonstrated that these side effects are limited to one of the two enantiomers, (+)-thioridazine. The question arises to whether the beneficial effects of thioridazine are limited to one enantiomer, or if (–)-thioridazine can prove itself to be useful in its pure enantiomeric state. The published procedures on the synthesis of the optically pure enantiomers of thioridazine were found to be unsatisfactory, either due to low optical purity, high cost, or problems scaling up. Herein, we have used an auxiliary-based strategy for the total synthesis of both enantiomers in high optical purity and good overall yield. The strategy can easily be scaled up. Both enantiomers were tested against several bacteria. Comparison of the racemic mixture, (–)-thioridazine and its (+)-antipode revealed that they have the same antimicrobial effects. Thus, the non-toxic enantiomer, (–)-thioridazine, can prove useful in this role and should be investigated further.

Mange studieretninger har grunnkurs i fag som ikke er hovedstudieretningen for programmet. Dette gjelder fag som matematikk, fysikk og kjemi. Erfaringsmessig er det vanskelig å motivere studenter i disse fagene som for mange kun blir støttefag. Samtidig kan man ikke forenkle studiet for mye siden det også skal danne grunnlag for de som skal gå videre til en mastergrad eller doktorgrad i faget. Vi har sett på muligheter for at studenten selv skal kunne få mange tilbud og selv kunne bestemme hvilke av disse tilbudene som passer best for den enkelte. Prosjektet ser spesielt på tilrettelegging innen kjemifaget, spesifikt innenfor grunnleggende organisk kjemi. Vi har konsentrert oss om innføring av en del digitale hjelpemidler hvor forskjellige spørsmålsdatabaser og (enkle) spill har vært elementer. Den enkle hypotesen er at alle studenter er ulike og at det som passer for én ikke nødvendigvis passer for en annen. F.eks. at noen synes at «gammeldagse» forelesninger er bra, mens andre ikke har læringsutbytte fra dette i det hele tatt. Tanken er at man inkluderer flere alternative læringsporter/læringsmetoder som gjør at studenten selv kan velge det som passer best for den enkelte. Dette legges ut digitalt slik at studenten selv kan velge det som er mest motiverende for den enkelte. I tillegg bør så mye av dette som mulig være robust nok til at ikke alt må forandres selv om man bytter lærebok. Prosjektet startet for flere år siden og har de siste 2 årene hatt støtte fra DIKU.

Monohydroxylated polyunsaturated fatty acids belonging to the oxylipin class of natural products are present in marine and terrestrial sources as well as in the human body. Due to their biological activities and role in diverse biosynthetic pathways, oxylipins biosynthesized from eicosapentaenoic acid and arachidonic acid have attracted great interest from the scientific community. One example is 3-hydroxyeicosapentaenoic acid where the absolute configuration at C-3 has only been tentatively assigned. In this paper, studies on acetate type aldol reactions that enabled the preparation of 3-(R)-hydroxyeicosapentaenoic acid (3R-HETE, 2) and its enantiomer are presented.

Dibromocyclopropanations are conventionally done by addition of dibromocarbene to alkenes under phase-transfer conditions in batch reactions using a strong base (50% NaOH (aq)), vigorous stirring and long reaction times. We have shown that cyclopropanation of unsaturated alcohols can be done under ambient conditions using continuous flow chemistry with 40% (w/w) NaOH (aq) as the base. The reactions were generally rapid; the yields were comparable to yields reported in the literature for the conventional batch reaction

A novel C1-symmetric dinitrogen ligand was synthesized in high yield from commercially available (1R,2R,3R,5S)-(−)-isopinocampheylamine and 1-methyl-2-imidazolecarboxaldehyde. In combination with Cu(OAc)2H2O, this new ligand promote the reaction between nitromethane and aliphatic aldehydes with high yields (up to 97%) and moderate enantioselectivities (up to 67% ee). The reactions with benzaldehyde required prolonged reaction time that resulted in diminished yields, but accompanied with ee-values in the 55%–76% range.

A thorough analysis of the fatty acid profiles of stipe and blade from the kelp species Laminaria hyperborea is presented. Lipid extracts were fractionated into neutral lipids, free fatty acids, and polar lipids, prior to derivatization and GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids α-linolenic acid, stearidonic acid, and eicosapentaenoic acid. The fatty acid amounts are higher in blade than in stipe (7.42 mg/g dry weight and 2.57 mg/g dry weight, resp.). The highest amounts of n-3 fatty acids are found within the neutral lipid fractions with 590.6 ug/g dry weight and 100.9 ug/g dry weight for blade and stipe, respectively. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. The blade had the highest PUFA/SFA ratio compared to stipe (1.02 versus 0.76) and the lowest n-6/n-3 ratio (0.8 versus 3.5). This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids compared to saturated- and monounsaturated fatty acids is known to influence human health. In the pharmaceutical, food, and feed industries, this can be of importance for production of different health products.

The present paper describes a total synthesis of racemic β-chamigrene (1), a sesquiterpene with a spiro[5.5]undecane carbon framework. Compared with previously reported β-chamigrene syntheses, we were able to reduce the total number of reaction steps, which also resulted in a significant improvement of the overall yield. The commercially available ketone 6-methylhept-5-en-2-one was transformed by known simple procedures into 3,3-dimethyl-2-methylenecyclohexanone. This reacted with isoprene by a Diels-Alder reaction to give a spiro ketone. An olefination reaction on this compound gave the target molecule.

The synthesis of the marine natural product 1,6Z,9Z,12Z,15Z-octadecapentaen-3-one (1) has been achieved by two different routes starting from the ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. Using EPA ethyl ester as starting material the polyunsaturated vinyl ketone lipid 1 was obtained in 17% overall yield.

Three different protocols for the syntheses of hydroxyalkylnitramines are presented and compared. Safety issues regarding the synthesis of nitramines are also discussed.