Design, synthesis and evaluation of rivastigmine and curcumin hybrids as site-activated multitarget-directed ligands for Alzheimer's disease therapy.

A series of novel 2-methoxy-phenyl dimethyl-carbamate derivatives were designed, synthesized and evaluated as site-activated MTDLs based on rivastigmine and curcumin. Most of them exhibited good to excellent AChE and BuChE inhibitory activities with sub-micromolar IC50 values. Among all the compounds, 6a demonstrated the most potent AChE inhibition with IC50 value of 0.097µM, which is about 20-fold than that of rivastigmine. In addition, the three selected compounds 5a, 6a and 6e demonstrated inhibitory activity against Aß self-aggregation similar to cucurmin in TEM assay, which is obviously different from the weak activity of rivastigmine. Moreover, the hydrolysate of 6a (compound 7) also showed potent ABTS(+) scavenging and moderate copper ion chelating activity in vitro.

[Identification of a HEK-293 cell line containing stably-transfected H3R gene and screening for novel non-imidazole histamine H3 receptor antagonists].

OBJECTIVE: To identify a HEK293 cell line containing stably-transfected H3R gene, and to screen the novel non-imidazole compounds with H3R antagonist activity. METHODS: The expression of rat H3 receptor in cell line was detected by RT-PCR and Western blot. An elevation of intercellular cAMP concentration induced by forskolin was measured as the index for screening compounds with H3R antagonist activity. RESULTS: The H3R-transfected HEK-293 cells stably expressed high level of rat H3 receptor mRNA and protein. Forskolin significantly increased intercellular cAMP concentration in the H3R-transfected HEK-293 cells. H3R agonist (R)-α-methylhistamine inhibited the forskolin-induced production of intercellular cAMP. H3R antagonist thioperamide and newly synthesized non-imidazole compounds XHA23 and XHA25 blocked (R)-α- methylhistamine reversal of forskolin-induced cAMP formation in a concentration-dependent manner, and the IC50 values were 3.62 µmol/L, 0.49 µmol/L, 0.14 µmol/L, respectively. CONCLUSION: The H3R-transfected HEK293 cells stably express high level of rat H3 receptor, and can be used for screening compounds with H3R antagonist activity. The non-imidazole compounds XHA23 and XHA25 may have H3R antagonist activity.

Design, synthesis and evaluation of 3-(2-aminoheterocycle)-4-benzyloxyphenylbenzamide derivatives as BACE-1 inhibitors.

Three series of 3-(2-aminoheterocycle)-4-benzyloxyphenylbenzamide derivatives, 2-aminooxazoles, 2-aminothiazoles, and 2-amino-6H-1,3,4-thiadizines were designed, synthesized and evaluated as ß-secretase (BACE-1) inhibitors. Preliminary structure-activity relationships revealed that the existence of a 2-amino-6H-1,3,4-thiadizine moiety and α-naphthyl group were favorable for BACE-1 inhibition. Among the synthesized compounds, 5e exhibited the most potent BACE-1 inhibitory activity, with an IC50 value of 9.9 µΜ and it exhibited high brain uptake potential in Madin-Darby anine kidney cell lines (MDCK) and a Madin-Darby canine kidney-multidrug resistance 1 (MDCK-MDR1) model.

Discovery of novel 2-piperidinol-3-(arylsulfonyl)quinoxalines as phosphoinositide 3-kinase α (PI3Kα) inhibitors.

A series of novel 2-aliphatic cyclic amine-3-(arylsulfonyl)quinoxalines was synthesized based on the structural features of a previously identified lead, WR1. The 2-piperidinol-3-(arylsulfonyl)quinoxalines, which showed excellent antitumor activities against five human cell lines, with inhibitory activities ranging from 0.34 to 2.32 µM, proved to be a promising class of novel PI3Kα inhibitors. The most potent compound 10d (WR23) showed an inhibitory IC(50) value of 0.025µM against PI3Kα and significant pAkt suppression effect. Molecular docking analysis was performed to determine possible binding modes between PI3Kα and target compounds.

Nutlin-1 strengthened anti-proliferation and differentiation-inducing activity of ATRA in ATRA-treated p-glycoprotein deregulated human myelocytic leukemia cells.

Unlike its cytotoxicity in p53-functional cell lines, Nutlin-1, the small-molecule inhibitor of murine double minute (MDM2), significantly enhanced the differentiation-inducing activity of all-trans retinoic acid (ATRA) in HL60 and NB4 cells (p53-nonfunctional) but not in U937 cells (p53 wild-type). Moreover, we demonstrated that the synergistic differentiation-inducing activity of Nutlin-1 combined with ATRA appeared in a p53-independent manner. In the present study, we found that ATRA could selectively induce expression of p-glycoprotein (p-gp) in HL60 and NB4 cells but not in U937 cells. Investigation of p-gp-ATPase activity showed that Nutlin-1 and ATRA were likely to act as p-gp transport substrates. Furthermore, Nutlin-1 enhanced the ability of ATRA to induce expression of the myeloid differentiation-related transcription factor C/EBPß and to reduce expression of c-myc. Additionally, the expression of retinoic acid receptor α (RARα) was further reduced in cells treated with ATRA in combination with Nutlin-1. Taken together, the mechanisms of synergistic differentiation-inducing activity of Nutlin-1 combined with ATRA could be attributed to Nutlin-1 competitive binding to p-gp, leading to ATRA efflux inhibition, and then the differentiation pathways involved were therefore further activated. Nutlin-1 might be a useful adjuvant with ATRA for patients with retinoid-resistant leukemia induced by overexpression of p-gp.

Synthesis and biological evaluation of novel 2-arylamino-3-(arylsulfonyl)quinoxalines as PI3Kα inhibitors.

A series of novel 2-arylamino-3-(arylsulfonyl)quinoxalines was synthesized through a newly developed approach. All synthesized target compounds were screened for their cytotoxicities against cancer cell lines including PC3, A549, HCT116, HL60 and KB. Representative compounds with favorable cytotoxicities were tested for their PI3Kα inhibitory activities. Among the synthesized target compounds, 17 (PI3Kα IC(50): 0.07 µM) displayed the most potent cellular activities (IC(50) values of 0.14 µM, 0.07 µM, 0.95 µM and 0.05 µM against PC3, A549, HCT116 and HL 60, respectively).

Pharmacophore identification, synthesis, and biological evaluation of carboxylated chalcone derivatives as CysLT1 antagonists.

The pharmacophore model (Hypo1) with a well prediction capacity for CysLT(1) antagonists was developed using Catalyst/HypoGen program. Virtual screening against an in-house database consisted of carboxylated chalcones using Hypo1 was performed. Retrieved hits 26a, 26b, 27a, and 27b were synthesized and biological evaluated, the results of which demonstrated that these compounds showed moderate to good CysLT(1) antagonistic activities. This study indicated that the generated model (Hypo1) is a reliable and useful tool in lead optimization for novel CysLT(1) antagonists.

[Method for screening cysteinyl leukotriene receptor 2 antagonists and preliminary screening of compounds].

OBJECTIVE: To establish a method for screening cysteinyl leukotriene receptor 2 (CysLT(2)) antagonists and to preliminarily screen a series of synthetic compounds. METHODS: Rat glioma cell line (C6 cells) highly expressing CysLT(2) receptor was used. Intracellular calcium concentration was measured after stimulation with the agonist LTD(4),which was used to screen compounds with antagonist activity for CysLT(2) receptor. Bay u9773, a CysLT1/CysLT(2) receptor non-selective antagonist, and AP-100984, a CysLT(2) receptor antagonist, were used as control. RESULT: PT-PCR showed a higher expression of CysLT(2) receptor in C6 cells. LTD(4) at 1 mumol/L significantly increased intracellular calcium in C6 cells; the maximal effect was about 37.5% of ATP, a positive stimulus.LTD(4)-induced increase of intracellular calcium was blocked by CysLT(2) receptor antagonists, but not by CysLT(1) receptor antagonists. Among the synthetic compounds, D(XW-)1,2,13,23,29 and 30 inhibited LTD(4)-induced increase of intracellular calcium. CONCLUSION: LTD(4)-induced change in intracellular calcium in C6 cells can be used as a screening method for CysLT(2) receptor antagonists. The compounds, D(XW-)1,2,13,23,29 and 30, possess antagonist activity for CysLT(2) receptor.

Design, synthesis, and biological evaluation of prenylated chalcones as vasorelaxant agents.

Five prenylated chalcones and one allylated chalcone were prepared according to the analysis based on support vector machine (SVM) classification model. Most of the synthesized chalcones showed potent vasorelaxant activities through evaluation in aortic rings with the endothelium pre-contracted by phenylephrine (PE), indicating that the experimental activities were in good agreement with the theoretical ones. Structure-activity relationship of these compounds showed that the substituent pattern and number of hydroxyl groups were crucial for their vasorelaxant activities and that the replacement of prenyl group with allyl group retained the potent activity.

Synthesis of four natural prenylflavonoids and their estrogen-like activities.

Four prenylflavonoids, bavachin 1, isobavachin 2, 7,4'-dihydroxy-8-prenylflavone 3, and 8-prenylapigenin 4 were synthesized and recognized for possessing estrogen-like activity in MCF-7/BOS cells, as evaluated by an estrogen-screening assay. All compounds significantly stimulated the proliferation of MCF-7/BOS cells in a dose-dependent manner. Isobavachin 2 showed the most potent activity, while bavachin 1 was the weakest. The estrogenic potency of these compounds is ranked as follows: 2 > 4 > 3 > 1.

[Study on extraction technology for extract and flavonoids in Chrysanthemum morifolium by orthogonal design].

OBJECTIVE: To ascertain extraction technology condition for extract and flavonoids from Chrysanthum morifoliwn. METHOD: The optimizing ultrasonic extraction condition on the basis of extractive yield and flavonoids were determined by orthogonal design. RESULT: The order of factors which affected the flavonoid extraction was extraction times > ethanol concentration > ultrasonic time > solvent quantity. CONCLUSION: The optimum ultrasonic extractions are A2B3C3D3. Compared with traditional extraction, ultraction method is timesaving, simple to operate, stable and need not be heated.

[Study on ultrasonic extraction techniques of flavonoids in Chrysanthemum morifolium].

OBJECTIVE: To optimize the ultrasonic extraction condition for flavonoids from Chrysanthemum morifolium. METHOD: The extraction rate of flavonoids optimized condition (ethanol concentration, ultrasonic time, solvent quantity and extraction times) was determined by orthogonal design. UV-Spectrophotometry was used for the determination. RESULT: The order of factors to affect the flavonoid extraction was ethanol concentration > extraction times > solvent quantity > ultrasonic time. CONCLUSION: The optimum ultrasonic extractions were: A2 B2 C3 D3. Compared with traditional extraction, ultraction method can save time, be easy to operate, improve extraction rates and need no heating.