Design and synthesis of 6-C-alkyl-DMDP type nanomolar inhibitors of ß-galactosidase and ß-glucosidase based on broussonetine S and related derivatives.

Broussonetine S (9), its C-1' and C-10' stereoisomers, and their corresponding enantiomers have been synthesized from enantiomeric arabinose-derived cyclic nitrones, with cross metathesis (CM), epoxidation and Keck asymmetric allylation as key steps. Glycosidase inhibition assays showed that broussonetine S (9) and its C-10' epimer (10'-epi-9) were nanomolar inhibitors of bovine liver ß-galactosidase and ß-glucosidase; while their C-1' stereoisomers were 10-fold less potent towards these enzymes. The glycosidase inhibition results and molecular docking calculations revealed the importance of the configurations of pyrrolidine core and C-1' hydroxyl for inhibition potency and spectra. Together with the docking calculations we previously reported for α-1-C-alkyl-DAB derivatives, we designed and synthesized a series of 6-C-alkyl-DMDP derivatives with very simple alkyl chains. The inhibition potency of these derivatives was enhanced by increasing the length of the side chain, and maintained at nanomolar scale inhibitions of bovine liver ß-glucosidase and ß-galactosidase after the alkyl groups are longer than eight or ten carbons for the (6R)-C-alkyl-DMDP derivatives and their 6S epimers, respectively. Molecular docking calculations indicated that each series of 6-C-alkyl-DMDP derivatives resides in the same active site of ß-glucosidase or ß-galactosidase with basically similar binding conformations, and their C-6 long alkyl chains extend outwards along the hydrophobic groove with similar orientations. The increasing inhibitions of ß-glucosidase and ß-galactosidase with the number of carbon atoms in the side chains may be explained by improved adaptability of longer alkyl chains in the hydrophobic grooves. In addition, the lower ß-glucosidase and ß-galactosidase inhibitions of (6S)-C-alkyl-DMDP derivatives than their C-6 R stereoisomers can be attributed to the misfolding of their alkyl chains and resulted decreased adaptability in the hydrophobic groove. The work reported herein is valuable for design and development of more potent and selective inhibitors of ß-galactosidase and ß-glucosidase, which have potential in treatment of lysosomal storage diseases. Furthermore, part of the 6-C-alkyl-DMDP derivatives and their enantiomers were also tested as potential anti-cancer agents; all the compounds tested were found with moderate cytotoxic effects on MKN45 cells, which would indicate potential applications of these iminosugars in development of novel anticancer agents.

Design, synthesis and structure-activity relationship of novel 2-pyrimidinylindole derivatives as orally available anti-obesity agents.

Due to the emerging global epidemic of obesity, developing safe and effective agents for anti-obesity is urgently needed. Our previous study found that 2-pyrimidinylindole derivative Wd3d exhibited potential anti-obesity activity. Herein, to further optimize the potential moiety, structural modifications were proceeded for two rounds in this study. Firstly, we designed, synthesized, and evaluated 36 new derivatives of 2-pyrimidinylindole scaffold with different substituents on the indole ring and pyrimidine ring to investigate their structure-activity relationship (SAR). Then, analogs with potent activity had the aldehyde group replaced with the acylhydrazone group to reduce cytotoxicity and improve metabolic stability. Detailed SAR studies and animal evaluation experiments led to the discovery of the compound 9ga, which significantly reduced TG accumulation with an EC50 value of 0.07 µM and showed relatively low cytotoxicity with an IC50 value of around 24 µM. Oral administration of 9ga effectively prevented the excessive growth of body weight and lessened fat mass as well as liver mass, decreased lipid accumulation in the liver and blood, and improved the heart injury parameter in the diet-induced obesity mouse model significantly better than Wd3d. A mechanism study showed that 9ga regulated the lipid metabolism during early adipogenesis by inhibiting PPARγ pathway. In conclusion, our study further highlights the anti-obesity potential of 2-pyrimidinylindole derivatives in diet-induced obesity.

Development of Novel N-Acylhydrazone Derivatives with High Anti-obesity Activity and Improved Safety by Exploring the Pharmaceutical Properties of Aldehyde Group.

The discovery of effective and safe antiobesity agents remains a challenging yet promising field. Our previous studies identified Bouchardatine derivatives as potential antiobesity agents. However, the 8a-aldehyde moiety rendered them unsuitable for drug development. In this study, we designed two series of novel derivatives to modify this structural feature. Through a structure-activity relationship study, we elucidated the role of the 8a-aldehyde group in toxicity induction. We identified compound 14d, featuring an 8a-N-acylhydrazone moiety, which exhibited significant lipid-lowering activity and reduced toxicity. Compound 14d shares a similar lipid-lowering mechanism with our lead compound 3, but demonstrates improved pharmacokinetic properties and safety profile. Both oral and injectable administration of 14d significantly reduced body weight gain and ameliorated metabolic syndrome in diet-induced obese mice. Our findings identify 14d as a promising antiobesity agent and highlight the potential of substituting the aldehyde group with an N-acylhydrazone to enhance drug-like properties.

Application of electroacupuncture in the prevention of low anterior resection syndrome after rectal cancer surgery.

BACKGROUND: Low anterior resection syndrome (LARS) is one of the common postoperative complications in patients with rectal cancer, which seriously affects their postoperative recovery and quality of life (QoL). Electroacupuncture therapy is one of the characteristic therapies of traditional Chinese medicine. There are few reports on the prevention and treatment of LARS by electroacupuncture therapy. AIM: To explore the clinical effectiveness of electroacupuncture in managing rectal cancer patients with postoperative LARS. METHODS: A total of 50 patients with LARS after rectal cancer surgery were retrospectively selected as the research subjects. According to the treatment methods, they were divided into an observation group (n = 25) and a control group (n = 25). During the four-week treatment period, the control group received standard defecation function training, while the observation group received electroacupuncture care and traditional defecation function training. The anal pressure index (which includes anal resting pressure, anal systolic pressure, and maximum tolerable volume), European Organization of Research and Treatment of Cancer (EORTC) QoL C30 (QLQ-C30) score, LARS Scale (LARSS) score, Wexner anal incontinence scale score, Xu Zhongfa five-item 10-point scale score, and the occurrence of adverse reactions were compared between the two groups before and after treatment. RESULTS: The experimental group showed considerably enhanced LARSS scores compared to those in the control group after four weeks of treatment. In the first week, second week, and fourth week, the LARSS score and Wexner anal incontinence scale score decreased, and the Xu Zhong method five-item 10-point scale score increased, with significant differences (P < 0.05). The experimental group showed substantial improvements in anal resting pressure, anal systolic pressure, and maximum tolerance volume after undergoing 4 wk of therapy in the untreated group (P < 0.05). The experimental group's QLQ-C30 score on the EORTC QoL questionnaire was higher than that of the control group during the 1st, 2nd, and 4th wk (P < 0.05). No significant variation between the groups in the frequency of adverse reactions (P > 0.05) was observed. CONCLUSION: Electroacupuncture positively impacted LARS following rectal cancer surgery, effectively improving clinical symptoms and anal pressure indicators and patients' standard of life.