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Additional file 1: Table S1. Half-life time of enzymes vs temperature of incubation.

The synthesis of a 1,S-lactone 2,4-O-alkylidene-D-erythrose derivative was found to be a highly stereoselective template in Michael addition trough the reaction of a D-erythrosyl 1,5-lactone derivative with nitrogen and sulfur nucleophiles. The sulfur adducts formed are 1 (D-erythrose derivative):1 (nucleophile), and the nitrogen adducts are 1:2. Both were then treated under HCl to give 2,6-dideoxy-4-functionalized-D-ribono-hexono-1,4-lactone by a reaction cascade in high overall yield. Reaction's scale up even improves the yield. The theoretical and computational results clearly explain the origin of the stereoselectivity, and the energetic course of reactions starting with nitrogen and sulfide nucleophiles. Considering that the 1,4-lactones obtained in this work offer a new molecular scaffold for organic synthesis, these new results provide a solid theoretical platform that can be used to speed up synthesis of other derivatives in a stereo- and regioselective way., We thank the NMR Portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho) and FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to CQ/UM and for Contract Grant No. IF/01310/2013.

Book of Abstracts of CEB Annual Meeting 2017, [Excerpt] Polyesters are polymers comprising of repeating ester groups as chain structure backbone, being the most popular biodegradable polymers. Many studies related with the synthesis of aliphatic and aromatic polyesters using chemical processes have been carried out [1]. Poly (ethylene glutarate) (PEG), Poly(ethylene malonate) (PEM), Poly(ethylene phthalate) (PEP) are attractive polyesters by virtue of their easiness in synthesis and widely diversity of applications such as textile manufacturing, microelectronics, bioprocessing, food packaging as well as in bio medical like surgical threads, contact lenses, supporting material in bone repairing, treat air leaks in lung injury. [...], info:eu-repo/semantics/publishedVersion

A set of 1,8-naphtalimides derivatives were synthesized and tested against three protozoans that cause important human diseases: Leishmaniainfantum, Trypanosomabrucei and Trypanosomacruzi. Additionally, toxicity was determined by growth inhibition of THP-1 derived macrophages. The results suggest that chemical modifications in the carbon chain linking the naphthalimide and the substituting groups have different effects in the parasites. This work should provide new insights new insights for the design and optimization of more potent and directed naphthalimide derivatives against these organisms., The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreements No.602773 (Project KINDRED). L.G. was supported by the Fundaçãopara a Ciência e Tecnologia through grant SFRH/BD/81604/2011.The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreements No.602773 (Project KINDRED). Thanks are due also to the NMR Portuguese network (PTNMR, BrukerAvance III 400Univ. Minho), and FCT and FEDER for financial support to CQ/UM., info:eu-repo/semantics/publishedVersion

Dissertação de mestrado em Química Medicinal, This thesis is divided into two parts. At first, two starting synthon compounds were obtained: the benzylidene acetal D-erythrose aldehyde and the unsaturated lactone derived from this aldehyde. Both compounds were obtained following methods reported in the literature. The first part of the work focuses on aldehyde reactions with different primary aliphatic amines, yielding the respective imines. These were reduced to afford the respective secondary amines in low to good yields. The cleavage of the benzylidene acetal group was conducted in an acid medium, leading to the synthesis of aminopolyols also in good yields. Carbon nucleophiles were added to imines, but without success; either the starting material was recovered or complex mixtures obtained. In the second part, the unsaturated lactone was studied regarding to its reactivity and selectivity. Epoxidation, bromination and aziridination reactions do not led to the expected products. The osmilation led to a single product, which after cleavage of the acetal in acidic medium gave the allonic acid. Reactions with carbon, sulfur and nitrogen nucleophiles also led to pure products. Nitromethane, benzyl mercaptan, ethanethiol and hydroxylamine gave substituted lactones at position 4 in good yields. Hydrazine, 2-aminoethanol, benzylamine and propylamine led to amides in yields that vary from good to quantitative. The acetal group in these compounds was also removed under acidic conditions to give polyhydroxylated 4-substituted-lactones in good to excellent yields; amides undergo intramolecular cyclization yielding L-hydroxylated lactams 4- and N-substituted in quantitative yield. Hydrogenation of the lactam with two benzyl groups, was found to be chemo-selective, cleaving the benzyl at the amine function, and retaining the benzyl at the amide function. Both lactones and lactams were subjected to enzymatic assays. One of the lactams showed excellent activity and selectivity for α-glucosidase, which makes it a potentially powerful anticancer agent., O presente trabalho encontra-se dividido em duas partes. Numa primeira abordagem foram sintetizados dois sintões de partida, um aldeído da D-eritrose, e uma ð-lactona insaturada, derivada do aldeído anterior. Os dois compostos foram obtidos seguindo metodologias reportadas na literatura. A primeira parte do trabalho debruça-se sobre reações do aldeído com diferentes aminas primárias alifáticas, obtendo-se as respetivas iminas, que foram reduzidas obtendo-se as respetivas aminas secundárias com rendimentos variados. A clivagem do grupo benzilideno acetal foi realizada em meio ácido, levando à síntese de aminopolióis, com bons rendimentos. Às iminas foram também adicionados nucleófilos de carbono, todavia sem sucesso, levando sempre à recuperação do reagente de partida ou à obtenção de misturas complexas. Na segunda parte do trabalho, a lactona obtida foi sujeita a estudos de reatividade e seletividade. Reações de epoxidação, bromação e aziridinação não levaram à obtenção do produto esperado. Por osmilação obteve-se um único produto, que após clivagem do acetal em meio ácido deu origem ao ácido alónico. Reações com nucleófilos de carbono, enxofre e azoto levaram também à obtenção de um produto puro. O nitrometano, o benzilmercaptano, o etanotiol e a hidroxilamina originaram lactonas substituídas na posição 4, com bons rendimentos. A hidrazina, o 2- aminoetanol, a benzilamina e a propilamina levaram à obtenção de uma amida com rendimentos entre bons e quantitativos. Após a remoção do acetal, em meio ácido, obtiveram-se ð-lactonas polihidroxiladas 4-substituídas com bons a excelentes rendimentos; as amidas sofreram um processo de ciclização intramolecular, originando L-lactamas polihidroxiladas N- e 4-substituídas com rendimento quantitativo. Foi possível encontrar um método de hidrogenação quimio-seletivo de um dos dois grupos benzilo contidos na lactama; apenas é removido o grupo benzilo da função amina. Tanto as lactonas finais como as lactamas foram submetidas a ensaios enzimáticos. Os resultados mostraram excelente atividade e seletividade de uma lactama para a α- glucosidase, o que a torna um potencial agente anticancerígeno.

Dissertação de mestrado em Química Medicinal, Nos dias de hoje, um mundo mais sustentável é cada vez mais um objetivo a atingir. Face a esta necessidade, a indústria cosmética tem vindo a desenvolver novos métodos de produção para satisfazer as necessidades do mercado. Deste modo, os ingredientes cosméticos têm sido substituídos por alternativas, produzidas através de processos sintéticos mais verdes (sem solvente, menor gasto energético e/ou com recurso a biocatalisadores). Nesta dissertação foram sintetizados seis compostos emulsificantes não iónicos O/A, utilizando n-heptano e a lipase modificada da Aspergillus oryzae como biocatalisador: o éster 2-(2- etoxietoxi)etiloctanoato (6a) (η=72%), o éster 2-(2-etoxietoxi)etildecanoato (6b) (η=68%), o éster 2-(2- etoxietoxi)etilpalmitato (6c) (η=68%), o éster 2-(2-etoxietoxi)etiloleato (6d) (η=68%), o éster 2-(2- etoxietoxi)etil(9Z,12Z)-octadeca-9,12-dienoato (6e) (η=75%) e o éster 2-etoxietiloctanoato (7a) (η=72%). As lipases nativas da Aspergillus oryzae, Candida rugosa e porcine pancreas foram também testadas, no entanto, revelaram baixa (Aspergillus oryzae) ou nenhuma atividade de esterificação (Candida rugosa e porcine pancreas). Estudos de modelação molecular foram realizados, tendo-se observado uma baixa afinidade dos substratos/produtos aos centros ativos destas enzimas. De modo a obter uma síntese mais verde, as reações com a lipase modificada foram efetuadas na ausência de solvente. Nestas foram apenas isolados os compostos 6d e 6e com um rendimento de 74% e 50%, respetivamente. Posteriormente os ésteres foram caracterizados, e foram estudadas as suas propriedades emulsificantes através da produção de nanoemulsões O/A com rácios de 2,5% e 5% de emulsificante em tampão PBS ou água. A estabilidade destas foi avaliada com recurso à técnica de DLS, que permitiu concluir que os compostos 6a e 6c não formam nanoemulsões estáveis, pelo balanço hidrofóbico-hidrofílico e pelo estado sólido do éster, respetivamente. As nanoemulsões formadas pelos restantes ésteres revelam-se estáveis durante, pelo menos, 4 meses, o que foi justificado com 60 ns de simulação de dinâmica molecular. Estas simulações revelaram que os ésteres 6b, 6e e 7a formam agregados com perfil micelar e o composto 6d forma agregados com perfil de bicamada fosfolipídica. Posteriormente foi encapsulado nestas nanoemulsões um corante hidrofóbico, o Nile Red. O corante foi eficientemente encapsulado nas nanoemulsões, o que foi confirmado através de microscopia confocal. No entanto, as nanoemulsões revelaram baixa capacidade na libertação do corante. O mesmo foi observado em estudos de permeação através de um sistema de transdermal., A more sustainable world is an emerging goal to achieve. Considering this, the cosmetic industry has been developing new production methods to meet the requirements needs of the market. In this way, cosmetic ingredients have been replaced by alternatives, produced through greener synthetic processes (solvent-free, lower energy expenditure and/or using biocatalysts). In this dissertation, six non-ionic O/W emulsifying compounds were synthesized using n-heptane and a modified lipase from Aspergillus oryzae as biocatalyst, the 2-(2- ethoxyethoxy)ethyloctanoate ester (6a) (η=72%), the 2-(2-ethoxyethoxy)ethyldecanoate ester (6b) (η=68%), the 2-(2-ethoxyethoxy)ethylpalmitate ester (6c) (η=68%), the 2-(2-ethoxyethoxy)ethyloleate ester (6d) (η=68%), the 2-(2-ethoxyethoxy)ethyl(9Z,12Z)-octadeca-9,12-dienoate ester (6e) (η=75%) and the 2-ethoxyethyloctanoate ester (7a) (η=72%). Native lipases from Aspergillus oryzae, Candida rugosa e porcine pancreas were also tested, however, revealed low (Aspergillus oryzae) or no esterification activity (Candida rugosa e porcine pancreas). Molecular modelling studies were conducted, showing a low affinity of the substracts/products to the active site of these enzymes. In order to obtain a greener synthesis, reactions with modified lipase were performed in the absence of solvent. These reactions only allowed to synthesize the compounds 6d and 6e with a yield of 74% and 50%, respectively. Subsequently the esters were characterized and their emulsifying properties were studied through the production of O/W nanoemulsions with emulsifier ratios of 2.5% and 5% in PBS buffer or water. Their stability was evaluated using the DLS technique, which allowed us to conclude that compounds 6a and 6c don’t form stable nanoemulsions due to the hydrophobic-hydrophilic balance and the solid state of the ester, respectively. The nanoemulsions formed by the remaining esters are stable for at least 4 months, which was justified with 60 ns of molecular dynamics simulation. These simulations revealed that esters 6b, 6e and 7a form aggregates with micellar profile and the compound 6d forms aggregates with phospholipid bilayer profile. Subsequently, a hydrophobic model dye, Nile Red, was encapsulated in these nanoemulsions. The dye was efficiently encapsulated in nanoemulsions, which was confirmed by confocal microscopy. However, its release was not observed, nor its permeation through a transdermal system.

Dissertação de mestrado em Química Medicinal, A procura de produtos “verdes” e sustentáveis é uma realidade cada vez mais indispensável na indústria cosmética, sendo a substituição dos silicones um dos pontos fundamentais. Neste sentido, o objetivo principal deste trabalho foi a síntese de potenciais alternativas aos silicones, implementando métodos de produção mais verdes e amigos do ambiente, e a sua posterior avaliação quando aplicadas numa formulação cosmética comercial. Para tal, foram inicialmente testadas diferentes lipases como biocatalisadores, nomeadamente Aspergillus oryzae, Candida rugosa, porcine pancreas e Thermomyces lanuginosus imobilizada em Immobead 150. Dos diferentes substratos testados, etilenoglicol, dietilenoglicol, 1,3-propanediol, 1- heptanol e 1-decanol para esterificação com três ácidos carboxílicos (heptanóico, octanóico e decanóico), foram isolados com sucesso seis compostos hidrofóbicos: heptil heptanoato 4a (ɳ=66%), heptil octanoato 4b (ɳ=71%), heptil decanoato 4c (ɳ=67%), decil heptanoato 5a (ɳ=73%), decil octanoato 5b (ɳ=72%) e decil decanoato 5c (ɳ=69%). De todas as lipases testadas, a Aspergillus oryzae nativa, Candida rugosa e porcine pancreas não revelaram qualquer atividade catalítica. A catálise enzimática com a lipase Aspergillus oryzae modificada sem solvente foi o método mais eficiente e económico, cujo pior e melhor rendimento, correspondem ao produto 4a e 5a, respetivamente, com 66% e 73%. A caracterização de cada composto foi efetuada por 1H RMN, HRMS, FTIR e termogravimetria. O potencial dos ésteres como alternativas viáveis aos silicones sintéticos foi confirmado, revelando propriedades semelhantes ao Cetiol® CC, ciclopentasiloxano (D5) e óleo de silicone 5 cSt (Sil.O5), nos diversos parâmetros avaliados. A viscosidade foi o parâmetro mais díspar, aumentando, de uma forma geral, com o aumento da cadeia carbonada. Foram produzidas nove formulações cosméticas, com a respetiva variação de silicone incorporado: C1 (Cetiol® CC), C2 (D5), C3 (Sil.O5), C4 (4a), C5 (4b), C6 (4c), C7 (5a), C8 (5b) e C9 (5c). Todos os cremes apresentaram qualidade e estabilidade dos compostos sintetizados, com alguma uniformidade na avaliação das características organoléticas e pH, superando os testes de estabilidade acelerada e em ciclos de temperatura extrema. Nos ensaios reológicos todos os produtos exibiram um comportamento pseudoplástico. O creme C1 apresentou a melhor homogeneidade e coesão, o C3 o maior valor de viscosidade, considerado o mais espesso e rígido quando em fluxo. O C6 aparentou ser o mais fluído e cremoso. Apesar de espalhável, o C4 pode ser percebido como espesso e firme devido à maior resistência ao escoamento. O C9 evidenciou o menor valor de deformação para atingir o ponto de rutura da estrutura e o C7 o maior número de microfissuras na estrutura. O aumento de temperatura para 37°C, não influenciou as formulações em estudo. As diferenças no perfil de textura foram mínimas, no entanto, os cremes C7 e C4 aparentaram ser mais espalháveis e menos espessos e pegajosos, e contrariamente, o C1 e C9 como mais firmes, coesos, pegajosos e de menor espalhamento. Entre um creme com o silicone e a alternativa produzida (C4), os voluntários deram a preferência sensorial a este último, demonstrando o potencial dos ésteres e uma preocupação com a sustentabilidade., The search for green and sustainable products is an increasingly indispensable reality in the cosmetic industry, leading to research on more "natural" products, capable of replacing synthetic ingredients. In this context, the main objective of this work was the development of silicone alternatives. For this purpose, a greener and more environmentally friendly production was adopted, followed by their incorporation and complete characterization in a commercial cosmetic formulation. In order to achieve this, different lipases including those from Aspergillus oryzae, Candida rugosa, porcine pancreas, and Thermomyces lanuginosus immobilized on Immobead 150 were initially investigated as biocatalysts. From the different substrates tested, such as ethylene glycol, diethylene glycol, 1,3-propanediol, 1-heptanol and 1-decanol for the esterification with three carboxylic acids (heptanoic, octanoic, and decanoic), six hydrophobic compounds were successfully isolated. These included heptyl heptanoate 4a (=66%), heptyl octanoate 4b (ɳ=71%), heptyl decanoate 4c (ɳ=67%), decyl heptanoate 5a (ɳ=73%), decyl octanoate 5b (ɳ=72%) and decyl decanoate 5c (ɳ=69%). Native Aspergillus oryzae, Candida rugosa and porcine pancreas did not exhibit any catalytic activity when compared to the other lipases studied. Enzymatic catalysis with the modified lipase from Aspergillus oryzae without solvent was the most efficient and economical method, whose worst and best yields correspond to products 4a and 5a, respectively, with 66% and 73%. Each compound was characterized using 1H NMR, HRMS, FTIR, and thermogravimetry. The potential of the esters as viable substitutes for synthetic silicones was confirmed, revealing similar properties to Cetiol® CC, cyclopentasiloxane (D5) and 5 cSt silicone oil (Sil.O5) in the various parameters evaluated. The most variable parameter was viscosity, which generally increased as the carbon chain lengthened. The following nine cosmetic formulations were produced, with the corresponding silicone variation included: C1 (Cetiol® CC), C2 (D5), C3 (Sil.O5), C4 (4a), C5 (4b), C6 (4c), C7 (5a), C8 (5b) e C9 (5c). All of the creams demonstrated the quality and stability of the synthesised compounds. The organoleptic properties showed similar behaviour between all formulations. In the rheological tests, all of the samples had a pseudoplastic behaviour. While C1 demonstrated the best homogeneity and cohesiveness, C3 had the highest viscosity value, and was judged to be the thickest and most firm when in flow. C6 seemed to be the creamiest and most fluid. Due to its higher flow resistance, C4 appear thicker and firmer even though it is spreadable. C7 exhibited the highest number of micro-cracks in the structure, whereas C9 displayed the lowest value of deformation required to reach the breaking point of the structure. The formulations under investigation were unaffected by the rise in temperature to 37°C. Although there were only minor differences in the textural profile, creams C7 and C4 seemed to be more spreadable and less thick and sticky, while C1 and C9 seemed harder, cohesive, sticky, and less spreadable. Between a commercial and an alternative cream (C4), the volunteers favoured the alternative cream over the one that included silicone, demonstrating the potential of esters on a sensory level and a concern for sustainability.