Design,synthesis and biological evaluation of azithromycin glycosyl derivatives as potential antibacterial agents

A series of 11,12-cyclic carbonate azithromycin-4″-O-carbamoyl glycosyl derivatives were designed, synthesized, and evaluated as antibacterial agents to search for target compounds with excellent activity. The results of preliminary antibacterial tests against eight strains in vitro revealed that all of the title compounds exhibited improved activities with broad spectrum compared with the parent compound. The glycosylated side chains may be the pharmacophores responsible for the improved activity.     

Synthesis, biological evaluation and mechanism studies of deoxytylophorinine and its derivatives as potential anticancer agents

Previous studies indicated that (+)-13a-(S)-deoxytylophorinine (1) showed profound anti-cancer activities both in vitro and in vivo and could penetrate the blood brain barrier to distribute well in brain tissues. CNS toxicity, one of the main factors to hinder the development of phenanthroindolizidines, was not obviously found in 1. Based on its fascinating activities, thirty-four derivatives were designed, synthesized; their cytotoxic activities in vitro were tested to discover more excellent anticancer agents. Considering the distinctive mechanism of 1 and interesting SAR of deoxytylophorinine and its derivatives, the specific impacts of these compounds on cellular progress as cell signaling transduction pathways and cell cycle were proceeded with seven representative compounds. 1 as well as three most potent compounds, 9, 32, 33, and three less active compounds, 12, 16, 35, were selected to proform this study to have a relatively deep view of cancer cell growth-inhibitory characteristics. It was found that the expressions of phospho-Akt, Akt, phospho-ERK, and ERK in A549 cells were greater down-regulated by the potent compounds than by the less active compounds in the Western blot analysis. To the best of our knowledge, this is the first report describing phenanthroindolizidines alkaloids display influence on the crucial cell signaling proteins, ERK. Moreover, the expressions of cyclin A, cyclin D1 and CDK2 proteins depressed more dramatically when the cells were treated with 1, 9, 32, and 33. Then, these four excellent compounds were subjected to flow cytometric analysis, and an increase in S-phase was observed in A549 cells. Since the molecular level assay results of Western blot for phospho-Akt, Akt, phospho-ERK, ERK, and cyclins were relevant to the potency of compounds in cellular level, we speculated that this series of compounds exhibit anticancer activities through blocking PI3K and MAPK signaling transduction pathways and interfering with the cell cycle progression.     

Synthesis and biological evaluation of pyrimidine bridged combretastatin derivatives as potential anticancer agents and mechanistic studies

A number of pyrimidine bridged combretastatin derivatives were designed, synthesized and evaluated for anticancer activities against breast cancer (MCF-7) and lung cancer (A549) cell lines using MTT assays. Most of the synthesized compounds displayed good anticancer activity with IC₅₀ values in low micro-molar range. Compounds 4a and 4p were found most potent in the series with IC₅₀ values of 4.67 µM & 3.38 µM and 4.63 µM & 3.71 µM against MCF7 and A549 cancer cell lines, respectively. Biological evaluation of these compounds showed that selective cancer cell toxicity (in vitro using human lung and breast cancer cell lines) might be due to the inhibition of antioxidant enzymes instigating elevated ROS levels which triggers intrinsic apoptotic pathways. These compounds were found nontoxic to the normal human primary cells. Compound 4a, was found to be competitive inhibitor of colchicine and in the tubulin binding assay it showed tubulin polymerization inhibition potential comparable to colchicine. The molecular modeling studies also showed that the synthesized compounds fit well in the colchicine-binding pocket.     

Synthesis, biological evaluation and mechanistic studies of totarol amino alcohol derivatives as potential antimalarial agents

Herein we report on the semisynthesis and biological evaluation of β-amino alcohol derivatives of the natural product totarol and other simple aromatic systems. All β-amino alcohol derivatives of totarol exhibited higher antiplasmodial activity than totarol [IC(50): 11.69 μM (K1, chloroquine and multi-drug resistant strain), and 11.78 μM (D10, chloroquine sensitive strain)]-12e was the most active [IC(50): 0.63 μM (K1), and 0.61 μM (D10)]. The phenyl and naphthyl β-amino alcohol derivatives were much less active than their corresponding totarol equivalents. The majority of the β-amino alcohol derivatives of totarol were more active against K1 than the D10 strains of Plasmodium falciparum, a trend similar to the inverse relationship observed with the established aryl-amino alcohol antimalarial mefloquine. Selected compounds were shown to affect erythrocyte morphology, inhibit erythrocyte invasion and trigger CQ accumulation.     

Synthesis, biological evaluation and molecular docking studies of 1,3,4-oxadiazole derivatives as potential immunosuppressive agents

A series of 1,3,4-oxadiazole derivatives derived from 4-methoxysalicylic acid or 4-methylsalicylic acid (6a-6z) have been first synthesized for their potential immunosuppressive activity. Among them, compound 6z displayed the most potent biological activity against lymph node cells (inhibition=38.76% for lymph node cells and IC(50)=0.31 μM for PI3Kγ). The preliminary mechanism of compound 6z inhibition effects was also detected by flow cytometry (FCM) and the compound exerted immunosuppressive activity via inducing the apoptosis of activated lymph node cells in a dose dependent manner. Docking simulation was performed to position compound 6z into the PI3Kγ structure active site to determine the probable binding model.     

Synthesis and biological evaluation of arylpiperazine derivatives as potential anti-prostate cancer agents

A novel scaffold of arylpiperazine derivatives was discovered as potent androgen receptor (AR) antagonist through rational drug designation based on our pre-work, leading to the discovery of a series of new antiproliferative compounds. Compounds 10, 16, 27, 29 and 31 exhibited relatively strong antagonistic potency against AR and exhibited potent AR binding affinities, while compounds 5, 6, 10, 14, 16, 19, 21, 27 and 31 exhibited strong cytotoxic activities against LNCaP cells (AR-rich) as well as also displayed the higher activities than finasteride toward PC-3 (AR-deficient) and DU145 (AR-deficient). Docking study suggested that the most potent antagonist 16 mainly bind to AR ligand binding pocket (LBP) site through hydrogen bonding interactions. The structure-activity relationship (SAR) of these designed arylpiperazine derivatives was rationally explored and discussed. These results indicated that the novel scaffold compounds demonstrated a step towards the development of novel and improved AR antagonists, and promising candidates for future development were identified.     

Synthesis and biological evaluation of novel acylhydrazone derivatives as potential antitumor agents

We have designed, synthesized, and evaluated as potential antitumor agents a series of 2-hydroxybenzylidene derivatives of the N-(2-trifluoromethylpiridyn-4-yl)anthranilic acid hydrazide, and some analogues bearing a (2-trifluoromethyl)piridyn-4-ylamino group in 3- or 4-position of benzohydrazide or 4-position of phenylacetohydrazide. Compounds 12e, 13e, 15e, and 16e, bearing a 4-(diethylamino)salicylidene group exhibited potent cytotoxicity, with averaged GI₅₀ values in sub-micromolar range, and a variety of cell selectivity at nanomolar concentrations. The determination of acute toxicity in athymic nudes mice proved some compounds to be non-toxic, making them good candidates for further study as antitumor agents.     

Synthesis and biological evaluation of 3-arylcoumarin derivatives as potential anti-diabetic agents

A variety of substituted 3-arylcoumarin derivatives were synthesised through microwave radiation heating. The method has characteristics of environmental friendliness, economy, simple separation, and purification process, less by-products and high reaction yield. Those 3-arylcoumarin derivatives were screened for antioxidant, α-glucosidase inhibitory and advanced glycation end-products (AGEs) formation inhibitory. Most compounds exhibited significant antioxidant and AGEs formation inhibitory activities. Anti-diabetic activity studies showed that compounds 11 and 17 were equipotent to the standard drug glibenclamide in vivo. According to the experimental results, the target compound 35 can be used as a lead compound for the development of new anti-diabetic drugs. The whole experiment showed that anti-diabetic activity is prevalent in 3-arylcoumarins, which added a new natural skeleton to the development of anti-diabetic active drugs.     

Synthesis and biological evaluation of methoxyphenyl porphyrin derivatives as potential photodynamic agents

A new meso-2,4,6-trimethoxyphenyl porphyrin covalently linked to a 2',6'-dinitro-4'-trifluoromethylphenyl group by an amine bond 5 and its metal complex with Cd(II) 6 was prepared. The photodynamic activities of 5 and 6 were evaluated in vitro on Hep-2 cells. A considerable increase in the photocytotoxic effect was found for 6, which has higher singlet molecular oxygen, O(2)((1)Delta(g)), production.     

Synthesis and biological evaluation of amide derivatives of diflunisal as potential anti-inflammatory agents

To improve the medicinal activity, the structure of diflunisal has been modified. Twenty-one amide derivatives of diflunisal were synthesized starting from diflunisal in three steps with total yields from 72% to 89%. All compounds were identified by ¹H NMR, MS, and elemental analysis. The anti-inflammatory and analgesic activities for 19 compounds were evaluated. It was found that 5m possesses an excellent anti-inflammatory activity and a good analgesic activity, maybe a potential anti-inflammatory agent.     

Synthesis and biological evaluation of amide derivatives of diflunisal as potential anti-tumor agents

To discover the new medicinal activity, the structure of diflunisal has been modified. Forty amide derivatives of diflunisal were synthesized starting from diflunisal in three steps. Their inhibition growth rate of human lung cancer cell (A549) and human endometrial adenocarcinoma cell (Ishikawa) in vitro was evaluated. The preliminary assay results showed that compounds 6j, 7o and 8c exhibited good anti-tumor activities and excellent selectivity for the Ishikawa cell, may be potential anti-tumor agents.     

Synthesis and biological evaluation of 3-carbamate smilagenin derivatives as potential neuroprotective agents

Studies indicated that smilagenin, isolated from Anemarrhena asphodeloides Bunge, could improve cognitive impairment and exhibit neuroprotective activity. On the basis of the structure of smilagenin, a series of derivatives were synthesized and evaluated for their neuroprotective effects of H₂O₂-induced, oxygen glucose deprivation-induced neurotoxicity in SH-SY5Y cells and LPS-induced NO production in RAW264.7 cells. Structure activity relationship of derivatives revealed that benzyl-substituted piperazine formate derivatives showed the potent neuroprotective activity such as A12. These findings may provide new insights for the development of neuroprotective agents against Alzheimer’s disease.     

Synthesis and biological evaluation of imidazol-2-one derivatives as potential antitumor agents

A new series of aryl substituted imidazol-2-one derivatives structurally related to combretastatin A-4 (CA-4) were synthesized and evaluated for their cytotoxic activities in vitro against various human cancer cell lines including MDR cell line. The cytotoxic effects of compounds 7b and 7i proved to be similar to or greater than that of docetaxel. The highly active compound 7b also exhibited excellent inhibitory activity on tumor growth in vivo.     

Synthesis,biological evaluation and molecular docking studies of amide-coupled benzoic nitrogen mustard derivatives as potential antitumor agents

A series of amide-coupled benzoic nitrogen mustard derivatives as potential EGFR and HER-2 kinase inhibitors were synthesized and reported for the first time. Some of them exhibited significant EGFR and HER-2 inhibitory activity. Of all the studied compounds, compounds 5b and 5t exhibited the most potent inhibitory activity, which was comparable to the positive control erlotinib. Docking simulation was performed to position compounds 5b and 5t into the EGFR active site to determine the probable binding model. Antiproliferative assay results indicated that some of the benzoic nitrogen mustard derivatives possessed high antiproliferative activity against MCF-7. In particular, compounds 5b and 5t with potent inhibitory activity in tumor growth inhibition may function as potential antitumor agents.     

Synthesis of new glycosyl biuret and urea derivatives as potential glycoenzyme inhibitors

O-Peracetylated 1-(β-d-glucopyranosyl)-5-phenylbiuret was prepared in the reaction of O-peracetylated β-d-glucopyranosylisocyanate and phenylurea. The reaction of O-peracetylated N-β-d-glucopyranosylurea with phenylisocyanate furnished the corresponding 1-(β-d-glucopyranosyl)-3,5-diphenyl- as well as 3-(β-d-glucopyranosyl)-1,5-diphenyl biurets besides 1-(β-d-glucopyranosyl)-3-phenylurea. O-Peracetylated 1-(β-d-glucopyranosyl)-5-(β-d-glycopyranosyl)biurets were obtained in one-pot reactions of O-peracetylated β-d-glucopyranosylamine with OCNCOCl followed by a second glycopyranosylamine of β-d-gluco, β-d-galacto and β-d-xylo configurations. O-Acyl protected 1-(β-d-glucopyranosyl)-3-(β-d-glycopyranosylcarbonyl)ureas were obtained from the reaction of β-d-glucopyranosylisocyanate with C-(glycopyranosyl)formamides of β-d-gluco and β-d-galacto configurations. The O-acyl protecting groups were removed under acid- or base-catalyzed transesterification conditions, except for the N-acylurea derivatives where the cleavage of the N-acyl groups was faster than deprotection. Some of the new compounds exhibited moderate inhibition against rabbit muscle glycogen phosphorylase b and human salivary α-amylase.     

Synthesis and mechanistic studies of novel spin-labeled combretastatin derivatives as potential antineoplastic agents

Two series (14a–d and 21a–h) of novel spin-labeled combretastatin derivatives were synthesized and evaluated for cytotoxicity against four tumor cell lines (K562, SGC-7901, Hela and HepG-2). Simultaneously, a representative compound 21a was selected to investigate the antitumor mechanisms of these synthetic compounds. The results indicated that some of the compounds showed significant cytotoxicity against four tumor cell lines in vitro and were more active than etoposide, a clinically available anticancer drug. Among the newly synthesized compounds, 21a, 21b and 21c displayed the greatest cytotoxicity against three tested tumor cell lines (HEPG-2, BGC-832 and Hela), with IC₅₀ values ranging from 0.15 to 1.05 μM, compared with values of 0.014–0.403 μM for 3-amino-deoxycombretastatin A-4 (3). In addition, the mechanistic analysis revealed that compound 21a effectively interfered with tubulin dynamics to prevent mitosis in cancer cells, leading to cell cycle arrest and, eventually, dose dependent apoptosis.     

Synthesis, biological evaluation and molecular docking studies of 1,3,4-thiadiazole derivatives containing 1,4-benzodioxan as potential antitumor agents

A series of 1,3,4-thiadiazole derivatives containing 1,4-benzodioxan (2a-2s) have been synthesized to screen for FAK inhibitory activity. Compound 2p showed the most potent biological activity against HEPG2 cancer cell line (EC(50)=10.28 μg/mL for HEPG2 and EC(50)=10.79 μM for FAK), which was comparable to the positive control. Docking simulation was performed to position compound 2p into the FAK structure active site to determine the probable binding model. The results of antiproliferative and Western-blot assay demonstrated that compound 2p possessed good antiproliferative activity against HEPG2 cancer cell line. Therefore, compound 2p with potent FAK inhibitory activity may be a potential anticancer agent against HEPG2 cancer cell.     

Synthesis, biological evaluation, and molecular docking studies of resveratrol derivatives possessing chalcone moiety as potential antitubulin agents

Twenty-three resveratrol derivatives possessing chalcone moiety were synthesized and characterized, and their biological activities were also evaluated as potential antiproliferation and tubulin polymerization inhibitors. Compound C19 exhibited the most potent activity in vitro, which inhibited the growth of HepG2, B16-F10, and A549 cell lines with IC(50) values of 0.2, 0.1, and 1.4 μg/mL, respectively. Compound C19 also exhibited significant tubulin polymerization inhibitory activity (IC(50)=2.6 μg/mL). Docking simulation was performed to position compound C19 into the tubulin-colchicine binding site to determine the probable binding mode.     

Synthesis of chalcone derivatives as potential anti-diabetic agents

Chalcones bearing electron donating or electron withdrawing substitutions were prepared and their glucose uptake activity was evaluated. Chalcone derivatives were synthesized in one step protocol with high purity and yield. Chalcones with chloro, bromo, iodo and hydroxy substitutions at position 2 on A-ring exhibited the highest activity with glucose medium concentration (210 to 236 mg/dl) compared to pioglitazone and rosiglitazone (230 and 263 mg/dl, respectively). Also chalcones with iodo substitution at position 3 on A-ring were comparably active (≤238 mg/dl). The structure-activity relationship of the tested chalcones was studied and the findings were supported statistically.     

Synthesis of diaryl-azo derivatives as potential antifungal agents

As compared with a commercially available agricultural fungicide hymexazol, some phenyl-azo phenol derivatives (e.g., 4a, 4b, 4f, 4n, 4q, 4u, and 4v) exhibited the more promising and pronounced antifungal activities in vitro against seven phytopathogenic fungi. It seemed that 4-((un)substituted phenylazo)-phenol and 4-((un)substituted phenylazo)-3-methylphenol might be considered as new lead structures for further design of agricultural fungicides.