Zhili Zuo

Unique fucosylated chondroitin sulfate (FCS) extracted from the sea cucumber Stichopus horrens was subjected to deacetylation and deaminative depolymerization to generate oligosaccharide fragments containing anTal-diol, which were further purified to obtain the trisaccharide ShFCS-3. Subsequently, the coupling of ShFCS-3 and 4-azidoaniline was achieved by reductive amination. After purification, the main product ShFCS-A1 and by-product ShFCS-A2 were obtained, which were identified as (N-(L-Fuc_2S4S-α1,3-D-GlcA-β1,3-D-anTalA_4S6S-1-)-4-azidoaniline) and (4S)-[2-(3-L-Fuc_2S4S-α1)-D-GlcA-β1]-2,4,5-trihydroxy-5-sulfated-pent-2-enoic-acid) by 1D/2D NMR spectroscopy, respectively. ELISA experiments revealed that ShFCS-A1 exhibited P-selectin inhibition rates of 19.73% ± 9.60% at 1 μM, 96.28% ± 2.37% at 10 μM, and near-complete inhibition (99.92% ± 0.84%) at 100 μM. ShFCS-A2 demonstrated inhibition rates of 8.29% ± 3.00% at 1 μM, 74.02% ± 8.80% at 10 μM, and maximal inhibition approaching 100% at 100 μM. Cellular-level experiments revealed that ShFCS-A1 and ShFCS-A2 inhibited P-selectin binding to HL-60 cells by 92.72% ± 0.85% and 96.97% ± 1.16% at 100 μM, respectively. Molecular docking analysis indicated binding energies of −5.954 kcal/mol for ShFCS-A1 and −6.140 kcal/mol for ShFCS-A2 with P-selectin, confirming their potent inhibitory effects. These findings highlight the therapeutic potential of FCS oligosaccharides as pharmacophores and provide an important foundation for developing novel small-molecule P-selectin inhibitors.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, whose pathologic features include dysregulated glucose homeostasis and lipid accumulation. Peroxisome proliferators-activated receptor a (PPAR alpha) is a key regulator of fatty acid metabolism and ketogenesis due to its regulatory pathways involve activating fatty acid uptake, accelerating fatty acid oxidation, inhibiting gluconeogenesis, and suppressing inflammation and fibrosis. Therefore, PPAR alpha is considered as a potential target for the treatment of NAFLD and some agonists have entered clinical trials, which drove us to discover more novel PPAR alpha agonists. In current work, new 3H-benzo[b] [1,4] diazepine PPAR alpha agonists were identified from the ChemDiv database by pharmacophore modeling, molecular docking, derivative structure search, and bioassays, where compound LY-2 and its derivatives (LY-10 similar to LY-19) were discovered to promote the expression of PPAR alpha downstream gene, carnitine palmitoyl transterase-1 alpha (cpt1 alpha). Among these active compounds, the EC50 value of LY-2 against increasing cpt1 alpha was 2.169 mu M. Furthermore, the effect of LY-2 on cpt1a was weakened when PPAR alpha knock down, which confirmed that it is a PPAR alpha agonist again. Finally, the results from molecular dynamics simulations and binding free energy calculations showed that pi-pi stacking and hydrogen bonding interactions played key roles in the binding of LY-2 and PPAR alpha protein and their complex maintained a stable structure to facilitate LY-2 to have a better binding affinity with PPAR alpha protein. Taken together, compound LY-2 might be a novel lead compound for the development of potent PPAR alpha agonists. [GRAPHICS] .

11β-Hydroxysteroid dehydrogenase 1 (11β-HSD1) represents a promising drug target for metabolic syndrome, including obesity and type 2 diabetes. Our initial screen of a collection of natural products from Danshen led to the identification of tanshinones as the potent and selective 11β-HSD1 inhibitors. To improve the druggability and explore the structure–activity relationships (SARs), more than 40 derivatives have been designed and synthesized using tanshinone IIA and cryptotanshinone as the starting materials. More than 10 derivatives exhibited potent in vitro 11β-HSD1 inhibitory activity and good selectivity over 11β-HSD2 across human and mouse species. Based on the biological results, SARs were further discussed, which was also partially rationalized by a molecular docking model of 1 bound to the 11β-HSD1. Remarkably, compounds 1, 17 and 30 significantly inhibited 11β-HSD1 in 3T3-L1 adipocyte and in livers of ob/ob mice, which merits further investigations as anti-diabetic agents. This study not only provides a series of novel selective 11β-HSD1 inhibitors with promising therapeutic potentials in metabolic syndromes, but also expands the boundaries of the chemical and biological spaces of tanshinones. Graphic Abstract