Intramolekulaariset, hapettavat ja metallivapaat C(sp2)-H-sidoksen aminaatiot 1H-indolisynteeseissä

Indolijohdannaiset ovat tärkeitä heterosyklejä, koska niillä on paljon sovelluksia materiaali- ja lääketieteessä. Niille on ole-massa lukuisia erilaisia synteesimenetelmiä. 2-Alkenyyliamiinien C-N-kytkentäreaktio on suoraviivainen ja tehokas tapa syntetisoida indolijohdannaisia. Näissä reaktioissa on usein käytetty katalyyttinä jotain siirtymämetallia, kuten palladiumia tai ruteniumia, mutta viime vuosina niiden rinnalle on tarjottu myös metallivapaita katalyyttejä. Tämän tutkielman kirjallisen osuuden ensimmäisessä osassa tarkastellaan intramolekulaarisia, hapettavia ja metallivapaita C-H-sidoksen aminaatioreaktioita 1H-indolisynteeseissä. Toisessa osassa perehdytään lyhyesti aktiivihiilen rakenteeseen, rakenteen modifiointiin, funktionaalisten ryhmien karakterisointiin ja aktiivisten ryhmien katalyyttisiin ominaisuuksiin. Tutkimusosassa näytetään, että eri lailla substituoidut aryyliamiinit voidaan hapettaa modifioidulla aktiivihiilellä ja terminaalisena hapettimena toimivalla molekulaarisella hapella indolijohdannaisiksi hyvillä saannoilla. Lisäksi tutkimusosassa on optimoitu karbokatalyysireaktioiden olosuhteet tilastollisia menetelmiä apuna käyttäen

Carbocatalytic Cascade Synthesis of Polysubstituted Quinolines from Aldehydes and 2-Vinyl Anilines

Oxidized active carbon (oAC) catalyses the formation of polysubstituted quinolines from o-vinyl anilines and aldehydes. The reaction proceeds in a cascade manner through condensation, electrocyclization and dehydrogenation, and gives access to a wide range of quinolines with alkyl and/or aryl substituents as demonstrated with 40 examples. The metal-free catalytic procedure allows a heterogeneous protocol for the synthesis of various polysubstituted quinolines. The mechanistic studies imply that both the acid and quinoidic groups in oAC are integral for the catalytic manifold.Peer reviewe

Effect of Hybrid Type and Harvesting Season on Phytochemistry and Antibacterial Activity of Extracted Metabolites from Salix Bark

Hundreds of different fast-growing Salix hybrids have been developed mainly for energy crops. In this paper, we studied water extracts from the bark of 15 willow hybrids and species as potential antimicrobial additives. Treatment of ground bark in water under mild conditions extracted 12-25% of the dry material. Preparative high-performance liquid chromatography is proven here as a fast and highly efficient tool in the small-scale recovery of raffinose from Salix bark crude extracts for structural elucidation. Less than half of the dissolved material was assigned by chromatographic (gas chromatography and liquid chromatography) and spectroscopic (mass spectrometry and nuclear magnetic resonance spectroscopy) techniques for low-molecular-weight compounds, including mono- and oligosaccharides (sucrose, raffinose, and stachyose) and aromatic phytochemicals (triandrin, catechin, salicin, and picein). The composition of the extracts varied greatly depending on the hybrid or species and the harvesting season. This information generated new scientific knowledge on the variation in the content and composition of the extracts between Salix hybrids and harvesting season depending on the desired molecule. The extracts showed high antibacterial activity on Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 0.6-0.8 mg/mL; however, no inhibition was observed against Escherichia coli, Enterococcus faecalis, and Salmonella typhimurium. MIC of triandrin (i.e., 1.25 mg/mL) is reported for the first time. Although antibacterial triandrin and (+)-catechin were present in extracts, clear correlation between the antibacterial effect and the chemical composition was not established, which indicates that antibacterial activity of the extracts mainly originates from some not yet elucidated substances. Aquatic toxicity and mutagenicity assessments showed the safe usage of Salix water extracts as possible antibacterial additives.Peer reviewe

Challenges in Synthesis and Analysis of Asymmetrically Grafted Cellulose Nanocrystals via Atom Transfer Radical Polymerization

When cellulose nanocrystals (CNCs) are isolated from cellulose microfibrils, the parallel arrangement of the cellulose chains in the crystalline domains is retained so that all reducing end-groups (REGs) point to one crystallite end. This permits the selective chemical modification of one end of the CNCs. In this study, two reaction pathways are compared to selectively attach atom-transfer radical polymerization (ATRP) initiators to the REGs of CNCs, using reductive amination. This modification further enabled the site-specific grafting of the anionic polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS) from the CNCs. Different analytical methods, including colorimetry and solutionstate NMR analysis, were combined to confirm the REG-modification with ATRP-initiators and PSS. The achieved grafting yield was low due to either a limited conversion of the CNC REGs or side reactions on the polymerization initiator during the reductive amination. The end-tethered CNCs were easy to redisperse in water after freeze-drying, and the shear birefringence of colloidal suspensions is maintained after this process.Peer reviewe

Tilinpäätösanalyysi : Vantaan Energia ja Kuopion Energia

Tämän opinnäytetyön tavoitteena oli tutkia kahden suomalaisen energiayhtiön, Vantaan Energian ja Kuopion Energian, taloudellista tilannetta laatimalla tunnuslukumuotoinen tilinpäätösanalyysi. Analysoinnissa käytettiin tilinpäätösanalyysin periaatteita. Työn lähtökohtana oli tekijän oma kiinnostus aiheeseen. Tutkimus on tyypiltään laadullinen aineiston analyysi, jonka tutkimusaineistona olivat Vantaan Energian ja Kuopion Energian tilinpäätökset vuosilta 2015–2019. Teoreettinen viitekehys käsitteli tilinpäätösanalyysin laatimista ja tunnuslukujen laskentaa. Analyysiin valittiin käytettävät analysointikohteet eli laskettavat tunnusluvut, joiden avulla päästiin tekemään itse tilinpäätösanalyysi. Opinnäytetyössä tutkittiin kohdeyritysten kehitystä vuosina 2016–2019 ja vertailtiin saatuja tuloksia keskenään sekä toimialaan nähden. Tilinpäätösanalyysi toteutettiin laskemalla kannattavuuden, maksuvalmiuden ja vakavaraisuuden tunnuslukuja tarkastelujakson ajalta. Tilinpäätösanalyysissa käytetyt tunnusluvut on laskettu Alma Talentin Tunnuslukuoppaan ohjeiden mukaisesti. Tehdyn tilinpäätösanalyysin perusteella voidaan todeta, että niin Vantaan Energialla kuin Kuopion Energiallakin laskettujen tunnuslukujen sekä toimialavertailun perusteella menee hyvin. Kokonaistulokset ovat kasvaneet reilusti vuosina 2015– 2019. Kasvu on kuitenkin melko maltillista

Spruce bark stilbenes as a nature-inspired sun blocker for sunscreens

Funding Information: Aalto University CHEMARTS is acknowledged as the initiator of the original concept of applying spruce bark extracts as UV protection additives. The authors would like to thank Petri Widsten (VTT), Owain Dawson and Maria Rodriguez (Aalto University), and Jean-Claude HUBAUD (Helioscience) for their skilful assistance in the UV absorbance measurements. Special thanks go to Heidi Henrickson from Aalto University for the language check. This work is part of the Academy of Finland's Flagship Programme under Project No. 318890 and No. 318891 (Competence Center for Materials Bioeconomy, FinnCERES). Publisher Copyright: © 2022 The Royal Society of ChemistryStilbene glucosides are a class of natural compounds that have been used as natural antioxidants and antifungal and antibacterial agents. Here, spruce bark extract, rich in stilbene glucosides, was used as a natural ultraviolet-protective additive for sunscreens. The ultrasound-assisted extraction of fresh Norway spruce (Picea abies) inner bark with 60% ethanol provided an extract in ca. 25% yield, of which one third consisted of three stilbene glucosides (astringin, isorhapontin and polydatin) which were fully characterized and quantified by 1D and 2D NMR spectroscopy and high resolution-liquid chromatography mass spectrometry (HR-LCMS). Emulsions of the extract were prepared and applied on polymethyl methacrylate (PMMA) plates to study the effect of the extract on UV light absorbance. A 10% emulsion with spruce crude extracts (containing 35% stilbene glucosides) alone provided UV protection equal to half the efficiency of commercial SPF 15 sun lotions, which also displayed a 21-32% higher SPF effect in comparison with the same dosages of alkali lignin nanoparticles using the same sunscreen emulsification process. A preparative scale chromatography was established for the first time as a fast and highly efficient method in the small-scale recovery of stilbene glucosides from spruce inner bark for full structural elucidation and has a good chance to be industrially scalable. Overall, this exploration may launch a new era for the application of stilbene glucosides of spruce bark extracts as genuine replacements for synthetic UV filters, upgrading this underappreciated bark residue from energy production to higher value cosmetic use.Peer reviewe

In Situ Adsorption of Red Onion (Allium cepa) Natural Dye on Cellulose Model Films and Fabrics Exploiting Chitosan as a Natural Mordant

Funding Information: This work was funded by the BioColour project supported by the Strategic Research Council at the Academy of Finland (Funding Nos. 327178 and 327195). The authors are also grateful for support from the FinnCERES Materials Bioeconomy Ecosystem. Ira Smal is acknowledged for assistance in laboratory work. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.Synthetic dyes and chemicals create an enormous impact on environmental pollution both in textile manufacturing and after the product’s lifetime. Biobased plant-derived colorants and mordants have great potential for the development of more sustainable textile dyeing processes. Colorants isolated from biomass residues are renewable, biodegradable, and usually less harmful than their synthetic counterparts. Interestingly, they may also bring additional functions to the materials. However, the extraction and purification of the biocolorants from biomass as well as their dyeing efficiency and color fastness properties require a more thorough examination. Here, we extracted red onion (Allium cepa) skins to obtain polyphenolic flavonoids and anthocyanins as biocolorants, characterized the chemical composition of the mixture, and used a quartz crystal microbalance and thin films of cellulose nanofibrils to study the adsorption kinetics of dyes onto cellulose substrates in situ. The effect of different mordants on the adsorption behavior was also investigated. Comparison of these results with conventional dyeing experiments of textiles enabled us to determine the interaction mechanism of the dyes with substrates and mordants. Chitosan showed high potential as a biobased mordant based both on its ability to facilitate fast adsorption of polyphenols to cellulose and its ability to retain the purple color of the red onion dye (ROD) in comparison to the metal mordants FeSO4 and alum. The ROD also showed excellent UV-shielding efficiency at low concentrations, suggesting that biocolorants, due to their more complex composition compared to synthetic ones, can have multiple actions in addition to providing aesthetics.Peer reviewe

In Situ Adsorption of Red Onion (Allium cepa) Natural Dye on Cellulose Model Films and Fabrics Exploiting Chitosan as a Natural Mordant

Synthetic dyes and chemicals create an enormous impact on environmental pollution both in textile manufacturing and after the product's lifetime. Biobased plant-derived colorants and mordants have great potential for the development of more sustainable textile dyeing processes. Colorants isolated from biomass residues are renewable, biodegradable, and usually less harmful than their synthetic counterparts. Interestingly, they may also bring additional functions to the materials. However, the extraction and purification of the biocolorants from biomass as well as their dyeing efficiency and color fastness properties require a more thorough examination. Here, we extracted red onion (Allium cepa) skins to obtain polyphenolic flavonoids and anthocyanins as biocolorants, characterized the chemical composition of the mixture, and used a quartz crystal microbalance and thin films of cellulose nanofibrils to study the adsorption kinetics of dyes onto cellulose substrates in situ. The effect of different mordants on the adsorption behavior was also investigated. Comparison of these results with conventional dyeing experiments of textiles enabled us to determine the interaction mechanism of the dyes with substrates and mordants. Chitosan showed high potential as a biobased mordant based both on its ability to facilitate fast adsorption of polyphenols to cellulose and its ability to retain the purple color of the red onion dye (ROD) in comparison to the metal mordants FeSO4 and alum. The ROD also showed excellent UV-shielding efficiency at low concentrations, suggesting that biocolorants, due to their more complex composition compared to synthetic ones, can have multiple actions in addition to providing aesthetics.Peer reviewe