Expectations for Manuscripts Contributing to the Field of Solvents in ACS Sustainable Chemistry & Engineering

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Sustainable Phenylalanine-Derived SAILs for Solubilization of Polycyclic Aromatic Hydrocarbons

The solubilization capacity of a series of sustainable phenylalanine-derived surface-active ionic liquids (SAILs) was evaluated towards polycyclic aromatic hydrocarbons—naphthalene, anthracene and pyrene. The key physico-chemical parameters of the studied systems (critical micelle concentration, spectral properties, solubilization parameters) were determined, analyzed and compared with conventional cationic surfactant, CTABr. For all studied PAH solubilization capacity increases with extension of alkyl chain length of PyPheOCn SAILs reaching the values comparable to CTABr for SAILs with n = 10–12. A remarkable advantage of the phenylalanine-derived SAILs PyPheOCn and PyPheNHCn is a possibility to cleave enzymatically ester and/or amide bonds under mild conditions, to separate polycyclic aromatic hydrocarbons in situ. A series of immobilized enzymes was tested to determine the most suitable candidates for tunable decomposition of SAILs. The decomposition pathway could be adjusted depending on the choice of the enzyme system, reaction conditions, and selection of SAILs type. The evaluated systems can provide selective cleavage of the ester and amide bond and help to choose the optimal decomposition method of SAILs for enzymatic recycling of SAILs transformation products or as a pretreatment towards biological mineralization. The concept of a possible practical application of studied systems for PAHs solubilization/separation was also discussed focusing on sustainability and a green chemistry approach

Design of sustainable ionic liquids based on l-phenylalanine and l-alanine dipeptides: Synthesis, toxicity and biodegradation studies

A series of dipeptide ionic liquids (ILs) with l-phenylalanine and l-alanine fragments in structure were synthesized and their possible degradation pathways were analyzed. Based on this analysis, potential transformation products (PTPs) were proposed and synthesized. All of these compounds (25 in total) went through microbial toxicity screening and aerobic biodegradation testing. Obtained results demonstrated that by investigating ILs and PTPs with a dipeptide fragment (in tandem with single amino acid analogues), the design of ILs with high biodegradation values in closed bottle test can be accomplished. One finding was that within the scope of the compounds studied, l-phenylalanine containing compounds were more biodegradable than l-alanine derivatives. In addition to the choice of amino acid residue, its position in the dipeptide IL structure also had a significant effect on biodegradability. PyCH2CO-Phe-Ala-OEt IL, where l-phenylalanine was in close proximity to the positively charged pyridinium sub-unit, gave higher biodegradation percentages compared to PyCH2CO-Ala-Phe-OEt IL, where alanine was closer to pyridinium than the phenylalanine residue. Analysis of PTPs data showed that the presence of an alanine residue resulted in undesirable (less green) PTPs more often compared to PTPs containing phenylalanine, especially when alanine was in close proximity to the pyridinium headgroup. Based on both toxicity and biodegradation testing results preferable and less preferable subunits can be chosen for the design of new sustainable chemicals based on amino acids. Results from this study demonstrate a potential of designing new sustainable chemicals using amino acid moieties as part of their structure

A new class of prophylactic metallo-antibiotic possessing potent anti-cancer and anti-microbial properties

Immunocompromised cancer patients are often at high risk of developing infections. Standard infection control measures are required to prevent the onset of infection but, under some circumstances, antimicrobial prophylaxis is necessary. We have developed a family of innovative metallo-antibiotics of general formula [Cu(N,N)(CipA)Cl] where N,N represents a phenanthrene ligand and CipA stands for a derivative of the clinically used fluoroquinolone antibiotic ciprofloxacin. The X-ray crystal structure of one member from this family, [Cu(phen)(CipA)Cl] (where phen is 1,10-phenanthroline), is also reported. These complexes combine into one drug entity a Cu-N,N-framework with DNA binding and DNA oxidant properties and an antibiotic derivative with known anti-proliferative and anti-microbial activities. The complexes were all found to exhibit excellent DNA recognition with binding affinity of lead agents in the order of ∼107 M(bp)−1. Biophysical studies involving calf thymus DNA indicate the complexes intercalate or semi-intercalate DNA via the minor groove. All complexes exhibited excellent nuclease activity with DNA strand scission being mediated predominantly via superoxide and hydroxyl radicals. The complexes were found to have promising anti-proliferative effects against a human breast adenocarcinoma cell line (MCF-7) and a human prostate carcinoma cell line (DU145) with low micromolar and, in some cases, nanomolar cytotoxicities observed. Selective targeting of Gram positive bacteria was also identified by this complex class with one lead compound having an order of magnitude greater potency against Methicillin-resistant S. aureus (MRSA) as compared to the CipA ligand. Importantly, from a clinical stand point, these complexes were also found to be well tolerated in an in vivo Galleria mellonella larvae model, which has both functional and structural similarities to that of the innate immune system of mammals

Expectations for Manuscripts on Biomass Feedstocks and Processing in ACS Sustainable Chemistry & Engineering

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Oxidised guanidinohydantoin (Ghox) and spiroiminodihydantoin (Sp) are major products of iron- and copper-mediated 8-oxo-7,8-dihydroguanine and 8-oxo-7,8-dihydro-2-deoxyguanosine oxidation

8-Oxo-7,8-dihydroguanine (8-oxoGua), an important biomarker of DNA damage in oxidatively generated stress, is highly reactive towards further oxidation. Much work has been carried out to investigate the oxidation products of 8-oxoGua by one-electron oxidants, singlet oxygen, and peroxynitrite. This report details for the first time, the iron- and copper-mediated Fenton oxidation of 8-oxoGua and 8-oxo-7,8-dihydro-29-deoxyguanosine (8-oxodGuo). Oxidised guanidinohydantoin (Ghox) was detected as the major product of oxidation of 8-oxoGua with iron or copper and hydrogen peroxide, both at pH 7 and pH 11. Oxaluric acid was identified as a final product of 8-oxoGua oxidation. 8-oxodGuo was subjected to oxidation under the same conditions as 8-oxoGua. However, dGhox was not generated. Instead, spiroiminodihydantoin (Sp) was detected as the major product for both iron and copper mediated oxidation at pH 7. It was proposed that the oxidation of 8-oxoGua was initiated by its one-electron oxidation by the metal species, which leads to the reactive intermediate 8-oxoGua?+, which readily undergoes further oxidation. The product of 8-oxoGua and 8-oxodGuo oxidation was determined by the 29-deoxyribose moiety of the 8-oxodGuo, not whether copper or iron was the metal involved in the oxidation

Expectations for Manuscripts in ACS Sustainable Chemistry & Engineering: Scope Summary and Call for Creativity

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