Liver microsomal stability is an important property considered for the screening of drug candidates in the early stage of drug development. Determination of hepatic metabolic stability can be performed by an in vitro assay, but it requires quite a few resources and time. In recent years, machine learning methods have made much progress. Therefore, development of computational models to predict liver microsomal stability is highly desirable in the drug discovery process. In this study, the in silico classification models for the prediction of the metabolic stability of compounds in rat and human liver microsomes were constructed by the conventional machine learning and deep learning methods. The performance of the models was evaluated using the test and external sets. For the rat liver microsomes (RLM) stability, the best model yielded the AUC values of 0.84 and 0.71 on the test and external validation sets, respectively. For the human liver microsome (HLM) stability, the best model exhibited the AUC values of 0.86 and 0.77 on the test and external validation sets, respectively. In addition, several important substructure fragments were detected using information gain and frequency substructure analysis methods. The applicability domain of the models was defined using the Euclidean distance-based method. We anticipate that our results would be helpful for the prediction of liver microsomal stability of compounds in the early stage of drug discovery.

Ultralong organic room temperature phosphorescence (RTP) is attracting increasing attention due to its fascinating optical phenomena and wide applications. Among various RTP, excimer phosphorescence is of fundamental significance, but it remains a considerable challenge to achieve flexible, multicolor and large‐area excimer RTP materials, which should greatly advance the understanding and development of organic light‐emitting devices. Herein, we present ultralong excimer RTP films by the self‐assembly and confinement of terpyridine (Tpy) derivatives in polymeric matrices. Strikingly, the self‐assembly of Tpy derivatives induces the formation of excimer complexes, thus immensely minimizing singlet‐triplet splitting energy (ΔEST) to promote the intersystem crossing process. Furthermore, the confinement by multiple hydrogen bonding interactions as well as the compact aggregation of phosphors jointly suppresses the nonradiative transitions, leading to long‐lived excimer RTP (τ = 543.9 ms, 19,000‐fold improvements over the powder). On account of the outstanding afterglow performance and color‐tunability of RTP materials, flexible and large‐area films were fabricated for intelligent display, anticounterfeiting, and time‐resolved information encryption.

One new steroid 1, together with seven known compounds 2 to 8, were discovered in the extract of a soil-derived fungus Aspergillus flavus JDW-1. The structure, including the absolute stereochemistry of new compound 1, was established by interpretation of extensive nuclear magnetic resonance spectroscopic data and further confirmed by X-ray crystallographic analysis. The cytotoxicity of 1 against the A-549, Hela, HCT-116, MGC-803, and HO-8910 cell lines was evaluated, which showed cytotoxicity with the half-maximal inhibitory concentration (IC50) values as 5.00 to 22.38 μM. Compounds 2 to 8 exhibited moderate radical scavenging activity against DPPH with IC50 values ranging from 4.7 to 28.5 μM.