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The fungal toxin Fumonisin B1 (FB1) is a strong inducer to trigger plant hypersensitive responses (HR) along with increased long chain bases (LCB) and long chain base phosphates (LCBP) contents, though the regulatory mechanism of FB1 action and how the LCB/LCBP signalling cassette functions during the process is still not fully understood. Here, we report sphingosine kinase 1 (SPHK1) as a key factor in FB1-induced HR by modulating the salicylic acid (SA) pathway and reactive oxygen species (ROS) accumulation in Arabidopsis thaliana. Overexpression of SPHK1 increases the FB1-induced accumulations of ROS and SA. The double mutant that simultaneously overexpresses SPHK1 and suppresses the SPPASE or DPL1, two enzymes are mainly responsible for Phyto-sphingosine-1-phosphate (Phyto-S1P) removal, showed enhanced susceptibility to FB1 killing and FB1-induced SA activation than the plants overexpress SPHK1 alone. Exogenous sphingosine-1-phosphate (S1P) can modulate the transcription of the SA-responsive marker gene PR1 in a concentration-dependent biphasic manner. Suppression of SPHK1 decreases SA production whereas promotes jasmonic acid (JA) biosynthesis in response to FB1 applications. Our findings indicate a role of SPHK1 in modulating FB1-triggered cell death via SA and JA pathway interactions. [ABSTRACT FROM AUTHOR]

Formic acid (FA) is one of the most promising vectors for sustainable hydrogen energy and it can be synthesized from renewable biomass resources. In this work, a range of heteropolyacid derived temperature-responsive catalysts (Ch n H 4-n PMo 11 VO 40 , n=1–3) were prepared by modifying H 3 PMo 12 O 40 heteropolyacid with an oxidation site V5+ and temperature-responsive monomer choline chloride (Ch+), and used for the cascade conversion of biomass derived cellulose into FA via hydrolysis-oxidation in water. The ChH 3 PMo 11 VO 40 with a Ch/H ratio of 1/3 exhibited an outstanding catalytic performance to give a 49.5% yield of FA at 165 °C after 3 h reaction time. Catalytic activity of Ch n H 4-n PMo 11 VO 40 was found to be related to its amount of H+ and V5+, while the recyclable ability of Ch n H 4-n PMo 11 VO 40 was found to be related to its amount of Ch+. The as-prepared catalyst could be perfectly recycled with a single decrease the temperature of reaction systems, and be reused four times with limit loss in catalytic activity. The developed temperature-responsive catalysts have both advantages of homogeneous catalyst and heterogeneous catalyst, which should have potential application in other reactions of lignocellulosic biomass valorization. [Display omitted] • Temperature-responsive heteropolyacid was synthesized by modifying choline chloride. • A facile cascade conversion of cellulose into formic acid with ChnH 4-n PMo 11 VO 40. • ChH 3 PMo 11 VO 40 yielded 49.5% formic acid from cellulose conversion in water. • Catalytic activity binds onto acidity group (H+) and oxidation group (V5+). • Recyclable ability related to temperature-responsive choline chloride (Ch+) group. [ABSTRACT FROM AUTHOR]

[Display omitted] Obesity is a growing global health problem and is associated with increased prevalence of many metabolic disorders, including diabetes, hypertension and cardiovascular disease. Pancreatic lipase (PL) has been validated as a key target for developing anti-obesity agents, owing to its crucial role in lipid digestion and absorption. In the past few decades, porcine PL (pPL) is always used as the enzyme source for screening PL inhibitors, which generate numerous pPL inhibitors but the potent inhibitors against human PL (hPL) are rarely reported. Herein, a series of salicylanilide derivatives were designed and synthesized, while their anti-hPL effects were assayed by a fluorescence-based biochemical approach. To investigate the structure–activity relationships of salicylanilide derivatives as hPL inhibitors in detail, structural modifications on three rings (A, B and C) of the salicylanilide skeleton were performed. Among all tested compounds, 2t and 2u were found possessing the most potent anti-PL activity, showing IC 50 values of 1.86 μM and 1.63 μM, respectively. Inhibition kinetic analyses suggested that both 2t and 2u could effectively inhibit hPL in a non-competitive manner, with the k i value of 1.67 μM and 1.70 μM, respectively. Fluorescence quenching assays suggested that two inhibitors could quench the fluorescence of hPL via a static quenching procedure. Molecular docking simulations suggested that 2t and 2u could tightly bind on an allosteric site of hPL. Collectively, the structure–activity relationships of salicylanilide derivatives as hPL inhibitors were carefully investigated, while two newly identified reversible hPL inhibitors (2t and 2u) could be used as promising lead compounds to develop novel anti-obesity drugs. [ABSTRACT FROM AUTHOR]