Fujian Institute of Microbiology

Simultaneous monitoring of multiple mech. stimuli is a widespread requirement in practical applications.However, decoupling the photoluminescence (PL) response to mech. stimuli remains elusive for organic emitters.Here, we achieved the decoupled response to grinding and compression in 5-methoxy-1-indanone modified tetraphenylethylene (TPE) derivatives (IT) by employing the hydrogen bonding cooperativity effect (HBCE).The synthesized IT crystals exhibit a significant red-shifted emission from 480 nm to 550 nm under compression and an increased PL quantum yield from 1.87% to 22.2% upon grinding.Detailed exptl. anal. shows that the strengthened C-H···O interactions between indanone units facilitate denser intermol. π-π stacking, while the weak C-H···π interactions between TPE units regulate intramol. orbital coupling.The synergy of these two effects enables the decoupling of responses to shear and normal forces during the grinding and compression processes.This HBCE-empowered decoupled responsiveness in the organic emitter opens avenues for the development of multistimuli-response smart materials.

Rakicidin J (1) and rakicidin K (2), two new cyclic depsipeptides, were isolated from culture broth of Micromonospora chalcea FIM-R150103. Their structures were elucidated by extensive analysis of NMR, HR-ESI-MS, and electronic circular dichroism (ECD) data. The two compounds showed strong cytotoxic activity against human colon carcinoma HCT-8 and human pancreatic cancer PANC-1 cells under normoxic and hypoxic conditions in the range of IC₅₀ values from 0.024 to 0.79 μg/mL. Moreover, compounds 1 and 2 also showed moderate antibacterial activity against ten Gram-positive bacterial strains with MIC values ranging from 4 to more than 32 μg/mL. Structure-activity relationship of these two compounds with a close analogue, rakicidin B1, is also discussed.

In this work, a neutral polysaccharide named NP-1 was obtained from the cell wall of Nocardia rubra FIM-21 by column chromatog.Its chem. structure was characterized by methylation anal., 2D NMR spectroscopic study, and other techniques.It was shown that NP-1 contained five types of monosacchrides, including mannose (Man), glucose (Glc), N-acetylglucosamine (GlcpNAc), galactose (Gal) and arabinose (Ara) in a molar ratio of 7.7:3:2:1:1.5.According to linkage anal. and NMR spectra, the backbone contains 1,6-linked Manp, 1,4-linked Glcp, and 1,6-linked Galp, with branches substituted at the C-6 of 1,4-linked Glcp and the C-2 of 1,6-linked Galp by GlcpNAc, and at C-2 of 1,6-linked Manp by Araf, Araf-1,5-Araf or GlcpNAc.Biol. activity research showed that NP-1 could stimulate the proliferation of RAW264.7 cells and enhance their phagocytosis and release of NO.