RESUMEN
Organic emitters capable of changing their luminescence properties in response to mechanical stimuli have recently attracted considerable attention. While mechanoresponsive switching of luminescence color has been widely investigated, there are only a limited examples regarding the on-off luminescence intensity switching by mechanical stimulation. Consequently, rational design guidelines for mechanoresponsive switching of luminescence intensity have not been established. Herein, on-off luminescence switching has been achieved by two-component organic emitters composed of phenanthroimidazolylbenzothiadiazoles, which exhibit mechanochromic luminescence (MCL), and non-emissive pigments. In these two-component emitters, the emission color can be tuned by changing the MCL dye, and the apparent color under room light can be modulated by changing the non-emissive pigment. Moreover, we have demonstrated the encryption and decryption of luminescent displays by using the two-component emitter. The present two-component strategy is expected to serve as a useful method for developing advanced mechanoresponsive luminescent materials.
RESUMEN
Virtual screening is a commonly used process to search for feasible drug candidates from a huge number of compounds during the early stages of drug design. As the compound database continues to expand to billions of entries or more, there remains an urgent need to accelerate the process of docking calculations. Reuse of calculation results is a possible way to accelerate the process. In this study, we first propose yet another virtual screening-oriented docking strategy by combining three factors, namely, compound decomposition, simplified fragment grid storing k-best scores, and flexibility consideration with pregenerated conformers. Candidate compounds contain many common fragments (chemical substructures). Thus, the calculation results of these common fragments can be reused among them. As a proof-of-concept of the aforementioned strategies, we also conducted the development of REstretto, a tool that implements the three factors to enable the reuse of calculation results. We demonstrated that the speed and accuracy of REstretto were comparable to those of AutoDock Vina, a well-known free docking tool. The implementation of REstretto has much room for further performance improvement, and therefore, the results show the feasibility of the strategy. The code is available under an MIT license at https://github.com/akiyamalab/restretto.
RESUMEN
The need to accelerate large-scale protein-ligand docking in virtual screening against a huge compound database led researchers to propose a strategy that entails memorizing the evaluation result of the partial structure of a compound and reusing it to evaluate other compounds. However, the previous method required frequent disk accesses, resulting in insufficient acceleration. Thus, more efficient memory usage can be expected to lead to further acceleration, and optimal memory usage could be achieved by solving the minimum cost flow problem. In this research, we propose a fast algorithm for the minimum cost flow problem utilizing the characteristics of the graph generated for this problem as constraints. The proposed algorithm, which optimized memory usage, was approximately seven times faster compared to existing minimum cost flow algorithms.
