Search

The fluorescent molecule 1,3‐di(nicotinoyloxy)‐2‐methylenepropane (L) can be a good candidate for construction of coordination polymers with photoluminescence (PL) properties. Self‐assembly of silver(I) hexafluorophosphate with this ligand in a mixture of methanol and dichloromethane produced a 1‐D helical coordination polymer consisting of [Ag(L)](PF6), whereas crystallization from an acetonitrile‐based medium afforded a 1‐D sinusoidal coordination polymer consisting of [Ag(L)(CH3CN)2](PF6) having intramolecular argentophilic Ag∙∙∙Ag and π∙∙∙πinteractions arising from the eclipsed conformation of L. These findings suggest that the final structures of the two products can be controlled by the reaction solvent media rather than the crystallization method or concentration. The physicochemical properties of the present silver(I) compounds were fully characterized by means of infrared spectroscopy, thermogravimetric analysis/differential scanning calorimetry, PL, single‐crystal x‐ray diffraction (XRD), and powder‐XRD measurements.

The prolonged use of enzymes under oxidative stress is a major challenge in enabling effective enzymatic reaction pathways. Herein, we report a biomimetic antioxidant defensive strategy capable of providing adequate protection of enzymes against superoxide-mediated oxidation. Superoxide dismutase (SOD) and catalase (CAT) were chosen as scavengers and covalently encapsulated into silica nanoreactors, together with glucose dehydrogenase (GDH), which simultaneously should produce the coenzyme nicotinamide adenine dinucleotide (NADH, reduced form). By the enzymatic reactions of SOD and CAT, the interior of silica nanoreactors becomes a “ROS safe zone” to protect the glucose-dependent NADH production of coencapsulated GDH. We further combined this protected NADH-producing module with photocatalytic nanoparticles that enable the light-triggered oxidation of NADH back to NAD+(oxidized form). In combination, these two modules allow interconversion between NAD+and NADH by the addition of glucose or by light irradiation (LED lamp or sunlight). This protection and regeneration strategy is a versatile tool for enzyme applications for biological reactors, catalysis, or prototypes of artificial organelles or building blocks that contains fragile biomolecules and rely on the coenzyme NAD+/NADH.

In situgeneration of anticancer agents at the place of the disease is a new paradigm for cancer therapy. The production of highly potent drugs by nanoreactors through a facile synthesis pathway is demanded. We report an oncolytic nanoreactor platform loaded with the enzyme glucose oxidase (GOX) to produce hydrogen peroxide. For the first time, we realized a core–shell structure with encapsulated GOX under mild synthetic conditions, which ensured high remaining activity of GOX inside of the nanoreactor. Moreover, the nanoreactor protected the loaded GOX from proteolysis and contributed to increased thermal stability of the enzyme. The nanoreactors were effectively taken up into different cancer cells, in which they produced hydrogen peroxide by consuming intracellular glucose and oxygen, thereby leading to effective death of the cancer cells. In summary, our robust nanoreactors are a promising platform for effective anticancer therapy and sustained enzyme utilization.

In this study, electronic sensors, gas chromatography–mass spectrometry (GC-MS), and GC-olfactometry (GC-O) were used to analyze the flavor of pomegranate seed oil (PSO) extracted from roasted pomegranate seeds. A preliminary study was conducted to determine the extent to which roasting treatment positively affects the physicochemical and sensory properties of pomegranate seeds, and a total of four conditions including raw were selected (raw, 160°C for 15 min, 160°C for 20 min, 180°C for 10 min). This study aimed to determine if the beneficial effects of roasting seeds are retained when the oil is extracted from the seeds, and to explore their potential use in the food industry as a fat-soluble material. Electronic tongue (E-tongue) analysis revealed that roasting enhanced umami and sweetness while reducing bitterness. A total of 46 and 50 volatile compounds were detected using the electronic nose (E-nose) and GC-MS, respectively. The major volatile compounds were Maillard reaction products, which were not detected in the raw samples, and the terpene content decreased after roasting. A total of 13 odor-active compounds analyzed by GC-O were identified, with the majority having odor-active value (OAV) above 1. This study provides an aroma profile of PSO that can be used as a primary database for controlling the aroma and selecting optimal roasting conditions for application in food processing.

Physical separation of reactions by interactive multicompartments in biological cells is an attractive motif to design efficient microreactors that create biomimetic cascade reactions. We present an aqueous compartment with three different subcompartments that comprise of silica nanoreactors with encapsulated enzymes, namely, β-glucosidase, glucose oxidase, and peroxidase, providing a model cascade reaction in confinement. The encapsulated enzymes retain their activity as the substrate can reach the active site and the silica shell further protects the enzymes from external stresses, such as heat and proteolytic degradation. We demonstrate the biomimetic cascade reaction in between the compartments (“organelles”) inside of an additional microconfinement (water-in-oil emulsion). This strategy will allow us to design efficient multicompartmentalized reactors for further biological and organic reactions.