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Abstract High power efficiency and low efficiency roll‐off at practical luminance are two requirements for new‐generation energy‐saving lighting technologies, which are still bottlenecks of thermally activated delayed fluorescence (TADF) white organic light‐emitting diodes (WOLED), despite the advantages of TADF materials and devices in low cost and high sustainability. Herein, we developed a spiro phosphine oxide host named SSOXSPO, which can form multiple and multidirectional intermolecular hydrogen bonds (IHB). The resulted multilevel IHB network integrates long‐range ordered and short‐range disordered alignments for suppressing triplet‐polaron quenching (TPQ) and triplet‐triplet annihilation (TTA). Electronic characteristics of SSOXSPO matrix are further regulated, leading to the optimal exciton allocation through balancing energy and charge transfer. As consequence, using SSOXSPO as host, the single‐emissive‐layer TADF WOLEDs realized the record performance, including ultralow operation voltage as ∼4.0 V, power efficiency beyond fluorescent tube (70.1 lm W−1) and negligible external quantum efficiency roll‐off (3%) at 1000 nits for indoor lighting. This work demonstrates that multiple interplays supported by host matrixes in TADF WOLEDs can facilitate the synergistic effects of TADF emitters on 100% exciton utilization.

Twenty-seven novel 12N-substituted aloperine derivatives were synthesized and investigated for their inhibitory effects on collagen α1 (I) (COL1A1) promotor in human hepatic stellate LX-2 cells, taking aloperine (1) as the hit. A structure-activity relationship (SAR) study disclosed that the introduction of suitable substituents on the 12N atom might enhance the activity. Compound 4p exhibited a good promise on down-regulating COL1A1 expression with the IC50 value of 16.5 μM. Its inhibitory activity against COL1A1 was further confirmed on both mRNA and protein levels. Meanwhile, it effectively inhibited the expression of other fibrogenic proteins, such as transforming growth factor β1 (TGF-β1) and smooth muscle actin (α-SMA). It also exhibited good in vivo safety profile with the oral LD50 value of 400 mg kg−1 in mice. The results initiated the anti-liver fibrogenic study of aloperine derivatives, and the key compound 4p was selected as a novel lead for further investigation against liver fibrogenesis.

Twenty new 12N-substituted matrinol derivatives were synthesized and evaluated for their inhibitory effects on collagen α1 (I) (COL1A1) promotor in human hepatic stellate LX-2 cells. The structure-activity relationship (SAR) revealed that introducing a 12N-benzeneaminoacylmethyl substitution might significantly enhance the activity. Compound 8a exhibited the highest inhibitory potency against COL1A1, and its inhibition activity against COL1A1 was further confirmed on both the mRNA and protein levels. It also effectively inhibited the expression of α smooth muscle actin (α-SMA), fibronectin and transforming growth factor β1 (TGFβ1), indicating an extensive inhibitory effect on the expression of fibrogenic genes. The primary mechanism study indicated that it might take action via the Integrin/FAK/PI3K/Akt signaling pathway. The results provided powerful information for further structure optimization, and compound 8a was selected as a novel anti-fibrogenic lead for further investigation.