As the cellular roles of RNA abundance continue to increase, there is an urgent need for the corresponding tools to elucidate native RNA functions and dynamics, especially those of short, low-abundance RNAs in live cells. Fluorescent RNA aptamers provide a useful strategy to create the RNA tag and biosensor devices. Corn, which binds with 3,5-difluoro-4-hydroxybenzylidene-imidazolinone-2-oxime (DFHO), is a good candidate for the RNA tag because of its enhanced photostability and red-shifted spectrum. Herein, we report for the first time the utilization of Corn as a split aptamer system, combined with RNA-initiated fluorescence complementation (RIFC), for monitoring RNA self-assembly and sensing microRNA. In this platform, the 28-nt Corn was divided into two nonfunctional halves (named probe I and probe II), and an additional target RNA recognition and stem part was introduced in each probe. The target RNA can trigger the self-assembly reconstitution of the Corn's G-quadruplex scaffold for DFHO binding and turn-on fluorescence. These probes can be transfected stably into mammalian cells and deliver the light-up fluorescent response to microRNA-21 (miR-21). Significantly, the probes have good photostability, with minimal fluorescence loss after continuous irradiation, and can be used for imaging of miR-21 in living mammalian cells. The proposed method is universal and could be applied to the sensing of other tumor-associated RNAs, including messenger RNA and noncoding RNA, as well as for monitoring RNA/RNA interactions. The Corn-based splitting aptamers show promising potential in the real-time visualization and mechanistic analysis of nucleic acids.Isobenzopyrylium ions are unique, highly reactive, aromatic intermediates which are largely unexplored in asymmetric catalysis despite their high potential synthetic utility. In this study, an organocatalytic asymmetric multicomponent cascade via dienamine catalysis, involving a cycloaddition, a nucleophilic addition, and a ring-opening reaction, is disclosed. The reaction furnishes chiral tetrahydronaphthols containing four contiguous stereocenters in good to high yield, high diastereoselectivity (up to >201), and excellent enantioselectivity (93-98% ee). The obtained products are important synthetic intermediates, and it is demonstrated that they can be used for the generation of frameworks such as octahydrobenzo[h]isoquinoline and [2.2.2]octane scaffolds. Furthermore, mechanistic experiments involving oxygen-18-labeling studies and density functional theory calculations provide a vivid picture of the reaction mechanism. Finally, the bioactivity of 16 representative tetrahydronaphthol compounds has been evaluated in U-2OS cancer cells with some compounds showing a unique profile and a clear morphological change.The aggregation process of α-synuclein (α-syn) is substantial in the pathogenesis of Parkinson's disease. Indolinone derivatives are inhibitors of α-syn aggregates and can be used as PET-based radiotracers for imaging α-syn fibrils. However, no investigations on the metabolism of indolinone derivatives have been reported until now. In the present research, a 13C and 15N isotope labeling strategy was developed to synthesize compound [13C2,15N]-(Z)-1-(4-aminobenzyl)-3-((E)-(3-phenyl)allylidene)indolin-2-one (M0'), which was then used in a study of metabolism in hepatocytes. The metabolites were characterized using accurate mass and characteristic ion measurements. In the metabolic system, compound M0' was the main component (accounting for 97.5% of compound-related components) after incubation in hepatocytes for 3 h, which indicated that compound M0' possessed great metabolic stability. Seven metabolites have been successfully verified by UPLC/Q TOF MS in metabolic studies, including hydroxyl M0' (M1'), hydroxyl and methylated M0' (M2'), N-acetylated M0' (M3'), sulfate of hydroxyl M0' (M4'), the glucose conjugate of M0' (M5'), glucuronide conjugate of M0' (M6'), and glucuronide conjugate of hydroxyl M0' (M7'). The study on metabolism provides the important information to develop effective α-syn aggregate inhibitors and new PET-tracer-related indolinone derivatives.Sulfur(VI) fluorine exchange click reaction was applied to the highly efficient synthesis of new N,N'-disubstituted sulfamide (R1NH-SO2-NHR2) derivatives as pesticide candidates. Diphenhydramine purchase Bioassays were conducted to evaluate both insecticidal and fungicidal activities of the target compounds. Preliminary results showed that the target molecules exhibited good bioactivities. In particular, insecticidal activities of compounds D25 and D21 against Plutella xylostella (LC50 = 2.42 and 3.87 μg·mL-1) were superior or adequate to that of commercial insecticide indoxacarb (LC50 = 3.99 μg·mL-1). Moreover, some compounds could also exhibit satisfactory fungicidal activity toward plant pathogens Pyricularia grisea, Botrytis cinerea, and Thanatephorus cucumeris. This work could bring new insights into the application of heterocyclic N,N'-disubstituted sulfamides as novel pesticides.Colored charge-transfer complexes can be formed by the association between electron-rich donor and electron-deficient acceptor molecules, bringing about the narrowing of HOMO-LUMO energy gaps so that they become capable of harnessing visible light. In an effort to facilitate the use of these widespread, but nonetheless weak, interactions for visible light photocatalysis, it is important to render the interactions strong and robust. Herein, we employ a well-known donor-acceptor [2]catenane-formed by the mechanical interlocking of cyclobis(paraquat-p-phenylene) and 1,5-dinaphtho[38]crown-10-in which the charge-transfer interactions between two 4,4'-bipyridinium and two 1,5-dioxynaphthalene units are enhanced by mechanical bonding, leading to increased absorption of visible light, even at low concentrations in solution. As a result, since this [2]catenane can generate persistent bipyridinium radical cations under continuous visible-light irradiation without the need for additional photosensitizers, it can display good catalytic activity in both photo-reductions and -oxidations, as demonstrated by hydrogen production-in the presence of platinum nanoparticles-and aerobic oxidation of organic sulfides, such as l-methionine, respectively. This research, which highlights the usefulness of nanoconfinement present in mechanically interlocked molecules for the reinforcement of weak interactions, can not only expand the potential of charge-transfer interactions in solar energy conversion and synthetic photocatalysis but also open up new possibilities for the development of active artificial molecular shuttles, switches, and machines.