绿卡色林衍生物的合成、体外代谢及体内活性研究

将选择性5-HT2C受体激动剂类减肥药绿卡色林分子中的仲胺转化成氨基甲酸酯类前药,设计合成了13个氨基甲酸酯类化合物.新化合物的结构经核磁共振波谱、红外光谱及高分辨质谱确证.通过体外代谢稳定性实验,筛选出半衰期长且可通过代谢持续产生绿卡色林的新化合物6b.对化合物6b的大鼠减肥药理实验结果表明,在日剂量相同的条件下,化合物6b给药1次/d比绿卡色林给药2次/d的减肥效果略好.     

Prednisolone succinate-glucosamine conjugate: Synthesis, characterization and in vitro cellular uptake by kidney cell lines

Prednisolone succinate-glucosamine(PSG) conjugate,a prodrug for prednisolone,was synthesized and confirmed by NMR and MS spectrum.The stabilities of the prodrug in PBS(pH 2.50,5.00,7.20,and 7.89) were studied.Cytotoxicity and uptake assay of the prodrug were perfomed on HK-2 and MDCK cell lines.The results showed that compared with prednisolone,the PSG not only did not increase the cytotoxicity but also improved the uptake to 2.2 times of prednisolone by the cells.Thus,it indicated that glucosamine might be a potential carrier for kidney-targeting delivery of prednisolone.     

Design, synthesis and in vitro evaluation of L-amino acid esters prodrugs of acyclic nucleoside phosphonates as anti-HBV agent

A series of novel L-amino acid esters prodrugs of acyclic nucleoside phosphonates was synthesized and their anti-HBVactivity was evaluated in HepG2 2.2.15 cells. Compound 1d exhibited more potent anti-HBV activity and lower cytotoxicity than those of adefovir dipivoxil with EC50 and CC50 values of 0.207 mmol/L and 2530 mmol/L, respectively.     

Synthesis,and in vitro and in vivo evaluation of a diphenylchlorin sensitizer for photodynamic therapy

This paper reports the synthesis of a new diphenylchlorin photosensitizer, 2,3-dihydro-5,15-di(3,5-dihydroxyphenyl)porphyrin (SIM01). The photodynamic properties, cell uptake and localization of SIM01 were compared with those of structurally related meso-tetra(hydroxyphenyl)chlorin (m-THPC). In vitro studies were conducted on rat glioma cells (C6) and human adenocarcinoma (HT-29), and in vivo studies on human colon adenocarcinoma cells (HT-29) and human prostate adenocarcinoma cells (PC3). Both dyes showed an absorption maximum at around 650 nm, with a molar extinction coefficient of 13017 M(-1) cm(-1) for SIM01 and 22718 M(-1) cm(-1) for m-THPC. Their capacity to generate singlet oxygen was identical, but differences in partition coefficients indicated that SIM01 was slightly more hydrophilic. In vitro, SIM01 was slightly more phototoxic than m-THPC for C6 cells (4.8 vs. 6.8 microg ml(-1)). However, phototoxicities were nearly identical for HT29 cells (0.45 microg ml(-1) for 5 h incubation followed by 300 mW, 20 J cm(-2)). Pharmacokinetics in vivo in mice, as determined by fibre spectrofluorimetry, showed that the SIM01 fluorescence signal in the tumor was maximal between 6 and 12 h after injection, as compared to 72 h for m-THPC. With a 2 mg kg(-1) dye dose and laser irradiation at 300 J cm(-2) (650 nm, 300 mW), the optimal PDT response occurred when the interval between injection and irradiation was 6 h for SIM01 and 24 h for m-THPC. For SIM01 with 5 mg kg(-1) injection, the optimal PDT response occurred with a 12 h delay and with the same irradiation parameters as described above, in this case the tumor response showing 40% growth. Considering the tumor volume doubling time, the value was 6.5 days in the control group and increased to 13.5 days with SIM01. Thus, SIM01 may be a powerful sensitizer characterized by strong in vitro and in vivo phototoxicity and faster tissue uptake and elimination than m-THPC.     

Synthesis and evaluation of antitumour activity in vitro and in vivo of chrysin salicylate derivatives

A series of chrysin salicylate derivatives as potential antitumour agents were synthesised and evaluated their antitumour activities in vitro and in vivo. Most of the compounds exhibited moderate to good activities against MCF-7 cells, HepG2 cells, MGC-803cells and MFC cells. Among them, compound 3f showed the most potent activity against MGC-803 cells and MFC cells with IC₅₀ values of 23.83 ± 3.68 and 27.34 ± 5.21 μM, respectively. The flow cytometry assay reconfirmed that compound 3f promoted the occurrence of tumour cells’ G1/S block under the inhibiting effect of compound 3f. Compound 3f possessed higher antitumour efficacy in tumour-bearing mice, compared with the positive control 5-Fu and the blank control saline.     

Polyamidoamine dendrimer and dextran conjugates: preparation,characterization, and in vitro and in vivo evaluation

Amide and ester conjugates of aceclofenac with polyamidoamine (PAMAM-G0) dendrimer zero generation and dextran (40 kDa) polymeric carrier, respectively, are presented. The prepared conjugates were characterized by UV, TLC, HPLC, IR, and ¹H NMR spectroscopy. The average degrees of substitution of amide and ester conjugates were determined and found to be (12.5 ± 0.24) % and (7.5 ± 0.25) %, respectively. The in vitro hydrolysis studies showed that dextran ester conjugate hydrolyzed faster in a phosphate buffer solution of pH 9.0 as compared to PAMAM dendrimer G0 amide conjugate, and followed the first order kinetics. No amount of the drug was regenerated at pH 1.2 in simulated gastric fluid. The dextran conjugate showed short half-life as compared to the PAMAM dendrimer conjugate. Anti-inflammatory and analgesic activities of the dendrimer conjugate were found to be similar to those of the standard drug. Results of chronic ulceroginic activity showed deep ulceration and high ulcer index for aceclofenac, whereas lower ulcer index was found for the PAMAM dendrimer and dextran (40 kDa) conjugates. Experimental data suggest that PAMAM dendrimer and dextran (40 kDa) can be used as carriers for the sustained delivery of aceclofenac along with a remarkable reduction in gastrointestinal toxicity.     

Benzylidene/2-aminobenzylidene hydrazides: Synthesis,characterization and in vitro antimicrobial evaluation

In this study a series of new mannich bases were synthesized and characterized by elemental and spectral (IR, ¹H NMR, ¹³C NMR) studies. All the synthesized compounds were evaluated for their antimicrobial activity by broth dilution method against two Gram negative strains (Escherichia coli and Pseudomonas aeruginosa), two Gram positive strains (Bacillus subtilis and Staphylococcus aureus) and fungal strain (Candida albicans and Aspergillus niger). Preliminary pharmacological evaluation revealed that the compounds (3f, 3i, 3j, and 3k) showed good activity against these strains. The result demonstrates the potential and importance of developing new mannich bases which would be effective against resistant bacterial and fungal strain.     

Genipin‐crosslinked gelatin hydrogel incorporated with PLLA‐nanocylinders as a bone scaffold: Synthesis,characterization, and mechanical properties evaluation

Nowadays, despite remarkable progress in developing bone tissue engineering products, the fabrication of an ideal scaffold that could meet the main criteria, such as providing mechanical properties and suitable biostability as well as mimicking the bone extracellular matrix, still seems challenging. In this regard, utilizing combinatorial approaches seems more beneficial. Here, we aim to reinforce the mechanical characteristics of gelatin hydrogel via a combination of Genipin‐based chemical cross‐linking and incorporation of the poly l ‐lactic acid (PLLA) nanocylinders for application as bone scaffolds. Amine‐functionalized nanocylinders are prepared via the aminolysis procedure and incorporated in gelatin hydrogel. The nanocylinder content (0, 1, 2, 3, and 4 wt%) and cross‐linking density (0.1, 0.5, and 1 wt/vol%) are optimized to achieve suitable morphology, swelling ratio, degradation rate, and mechanical behaviors. The results indicate that hydrogel scaffold cross‐linking by 0.5 wt% of Genipin shows optimized morphological feathers with a pore size of around 300 to 500 μm as well as an average degradation rate (40.09% ± 3.08%) during 32 days. Besides, the incorporation of 3 wt% PLLA nanocylinders into the cross‐linked gelatin scaffold provides an optimized mechanical reinforcement as compressive modulus, and compressive strength show a 4‐ and 2.6‐fold increase, respectively. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay indicates that the scaffold does not have any cytotoxicity effect. In conclusion, gelatin composite reinforced with 3 wt% PLLA nanocylinders cross‐linked via 0.5 wt/vol% Genipin is suggested as a potential scaffold for bone tissue engineering applications.     

In vitro and in vivo degradation of an injectable bone repair composite

In vitro and in vivo degradation behaviors of an injectable bone regeneration composite (IBRC) which comprised of nano-hydroxyapatite/collagen (nHAC) particles in alginate hydrogel carrier were investigated. In vitro degradation quantitative testing indicated that the alginate had a faster degradation rate in simulated body fluid (SBF) than in deionized water at 37 °C. Similarly, IBRC also had a higher degradation rate in SBF than in deionized water at 37 °C, which was evaluated by alginate molecular weight measurement, mechanical properties test and degradation kinetics evaluation. But molecular weight of alginate degraded slower in IBRC than that in aqueous solution. In vitro results showed that degradation medium SBF had influence on degradation of alginate molecules. In the in vivo degradation study, surprisingly, there was no obvious decreasing of molecular weight of alginate from 0 to 8 weeks. IBRC degraded mostly after 24 weeks implantation and was replaced by connective tissue. No fibrous capsule and acute inflammatory reaction were found during the observed 24 weeks after IBRC implantation. There is only a mild short-term inflammatory response in rat dorsum muscle. These results indicated that IBRC had a controllable degradability and biocompatibility. Therefore, IBRC may be a promising degradable material for bone repair and bone tissue engineering.     

Reducible polyethylenimine hydrogels with disulfide crosslinkers prepared by michael addition chemistry as drug delivery carriers: Synthesis,properties, and in vitro release

Degradable hydrogels crosslinked with disulfide bonds were prepared by Michael addition between amine groups of branched polyethylenimine and carbon–carbon double bonds of N,N′‐bis(acryloyl)cystamine. The influences of the chemical composition of the resulted hydrogels on their properties were examined in terms of morphology, surface area, swelling kinetics, and degradation. The hydrogels were uniformly crosslinked and degraded into water‐soluble polymers in the presence of the reducing agent of dithiothreitol, which improved the control over the release of encapsulated drug. The degradation of hydrogels can trigger the release of encapsulated molecules, as well as facilitate the removal of empty vehicles. Results obtained from in vitro drug release suggested that the disulfide crosslinked hydrogels exhibited an accelerated release of encapsulated drug in dithiothreitol‐containing PBS buffer solution. Moreover, the drug release rate decreased gradually with increasing crosslinking density. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4074–4082, 2009     

One-step labelling of a novel small-molecule peptide with astatine-211: preliminary evaluation in vitro and in vivo

In this paper, VP2, a novel small molecule fusion peptide, was labelled with ²¹¹At through a one-step method (coupled with bifunctional intermediate SPC first and then labelled) with a radiochemical yield of about 45%. The radiochemical purity was still > 95% after 24 h at room temperature. Specificity studies in vitro indicated that ²¹¹At-SPC-VP2 has a high affinity for several tumour cells. Additionally, biodistribution in KM mice showed that ²¹¹At-SPC-VP2 has sufficient stability in vivo. This research suggested that ²¹¹At–SPC-VP2 produced by the convenient method has the potential to be a novel targeted drug for cancer radiotherapy.     

Carbonyl and carboxylate crosslinked cyclodextrin as a nanocarrier for resveratrol: in silico,in vitro and in vivo evaluation

Recently, much attention has been devoted towards the development of methods for the capture and separation of inorganic gases and organic compounds with high selectivity and efficiency using nanoporous materials. Unlike metal–organic frameworks and covalent organic network polymer, nanoporous molecular crystals (NMCs) do not have extended network structures through coordination or covalent bonding. Instead, they are composed of discrete organic molecules with only weak noncovalent interactions between them. Calixarenes, used as artificial hosts for molecular recognition, constitute a representative class of NMCs that exhibit “porosity without pores.” Despite the absence of empty-channels, calixarene crystals can absorb various inorganic gases and organic compounds, thereby undergoing a guest-induced structural change. Thus, because of their ability to precisely discriminate between molecules of similar sizes and structures, such NMCs show great potential for application as separation materials. This review summarizes reports on the absorption and inclusion of inorganic gases and organic molecules with crystals of calixarenes and their derivatives and discusses their potential as separation materials.     

Stimuli‐responsive zein‐based nanoparticles as a potential carrier for ellipticine: Synthesis,release, and in vitro delivery

In the present research, we have investigated a drug delivery system based on the pH‐responsive behaviors of zein colloidal nanoparticles coated with sodium caseinate (SC) and poly ethylene imine (PEI). These systematically designed nanoparticles were used as nanocarriers for encapsulation of ellipticine (EPT), as an anticancer drug. SC and PEI coatings were applied through electrostatic adsorption, leading to the increased size and improved polydispersity index of nanoparticles as well as sustained release of drug. Physicochemical characteristics such as hydrodynamic diameter, size distribution, zeta potential and morphology of nanoparticles prepared using different formulations and conditions were also determined. Based on the results, EPT was encapsulated into the prepared nanoparticles with a high drug loading capacity (5.06%) and encapsulation efficiency (94.8%) under optimal conditions. in vitro experiments demonstrated that the release of EPT from zein‐based nanoparticles was pH sensitive. When the pH level decreased from 7.4 to 5.5, the rate of drug release was considerably enhanced. The mechanism of pH‐responsive complexation in the drug encapsulation and release processes was extensively investigated. The pH‐dependent electrostatic interactions and drug state were hypothesized to affect the release profiles. Compared to the EPT‐loaded zein/PEI nanoparticles, the EPT‐loaded zein/SC nanoparticles exhibited a better drug sustained‐release profile, with a smaller initial burst release and longer release period. According to the results of in vitro cytotoxicity experiments, drug‐free nanoparticles were associated with a negligible cytotoxicity, whereas the EPT‐loaded nanoparticles displayed a high toxicity for the cancer cell line, A549. Our findings indicate that these pH‐sensitive protein‐based nanoparticles can be used as novel nanotherapeutic tools and potential antineoplastic drug carriers for cancer chemotherapy with controlled release.     

Synthesis,structure and in vitro biological evaluation of new lupane and dammarane triterpenoids fused with pyrazine heterocycle

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Glycosylated diazeniumdiolate-based oleanolic acid derivatives: synthesis, in vitro and in vivo biological evaluation as anti-human hepatocellular carcinoma agents

A series of O(2)-glycosylated diazeniumdiolate-based derivatives of oleanolic acid (4-19) were synthesized and their anti-human hepatocellular carcinoma (HCC) activities were evaluated. Compound 6 selectively inhibited HCC, but not non-tumor liver cell proliferation. This inhibition was attributed to high levels of nitric oxide (NO) released in HCC cells. Importantly, 6 exhibited low acute toxicity (LD(50) = 173.3 mg kg(-1)) and potent inhibition of HCC tumor growth in mice (3 mg kg(-1) iv). Furthermore, 6 induced HCC cell apoptosis, which was accompanied by lower mitochondrial membrane potentials and Bcl2 expression, but with higher cytochrome C release, Bax, caspase 3 and 9 expression activities in HCC cells. Collectively, 6 may be a promising candidate drug for the intervention of HCC.     

Photoaffinity labels for insect juvenile hormone binding proteins: Synthesis and evaluation in vitro

The interactions of insect juvenile hormones (JH) with proteins are critically important to titer regulation, transport, and hormone action at a molecular level. We have synthesized several JH analogs bearing photolabile diazocarbonyl groups as potential photoaffinity labels for JH binding proteins (JHBP). The most promising compound, 10, 11-epoxyfarnesyl diazoacetate (2) (EFDA) competes with JH III for The JH binding site of JHBP from Leucophaea hemolymph and ovaries and from cultured Drosophila cells. Moreover, irradiation of protein solutions containing micromolar amounts of EFDA gave irreversible loss of [³H]-JH III binding capacity with no change in binding affinity of the unlabelled protein. The protein could be protected against photoinactivation by the presence of equimolar JH III during irradiation. High specific activity [10-³H]-EFDA was prepared and used to demonstrate specific, finite binding of EFDA to the JH III receptor site of the binding protein. Further applications of photoaffinity labelling technique to characterization and cellular localization of the JHBP are discussed.     

Identification and characterization of in vitro and in vivo fidarestat metabolites: Toxicity and efficacy evaluation of metabolites

The progression of diabetic complications can be prevented by inhibition of aldose reductase and fidarestat considered to be highly potent. To date, metabolites of the fidarestat, toxicity, and efficacy are unknown. Therefore, the present study on characterization of hitherto unknown in vitro and in vivo metabolites of fidarestat using liquid chromatography–electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS) is undertaken. In vitro and in vivo metabolites of fidarestat have been identified and characterized by using LC/ESI/MS/MS and accurate mass measurements. To identify in vivo metabolites, plasma, urine, and feces samples were collected after oral administration of fidarestat to Sprague–Dawley rats, whereas for in vitro metabolites, fidarestat was incubated in human S9 fraction, human liver microsomes, and rat liver microsomes. Furthermore, in silico toxicity and efficacy of the identified metabolites were evaluated. Eighteen metabolites have been identified. The main in vitro phase I metabolites of fidarestat are oxidative deamination, oxidative deamination and hydroxylation, reductive defluroniation, and trihydroxylation. Phase II metabolites are methylation, acetylation, glycosylation, cysteamination, and glucuronidation. Docking studies suggest that oxidative deaminated metabolite has better docking energy and conformation that keeps consensus with fidarestat whereas the rest of the metabolites do not give satisfactory results. Aldose reductase activity has been determined for oxidative deaminated metabolite (F‐1), and it shows an IC50 value of 0.44 μM. The major metabolite, oxidative deaminated, did not show any cytotoxicity in H9C2, HEK, HEPG2, and Panc1 cell lines. However, in silico toxicity, the predication result showed toxicity in skin irritation and ocular irritancy SEV/MOD versus MLD/NON (v5.1) model for fidarestat and its all metabolites. In drug discovery and development research, it is distinctly the case that the potential for pharmacologically active metabolites must be considered. Thus, the active metabolites of fidarestat may have an advantage as drug candidates as many drugs were initially observed as metabolites.     

HPMA copolymer-doxorubicin-gadolinium conjugates: synthesis, characterization, and in vitro evaluation

This study describes the synthesis, characterization, and in vitro evaluation of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-gadolinium (Gd)-doxorubicin (Dox) conjugates. Copolymers of HPMA were derivatized to incorporate side chains for Gd chelation and Dox conjugation. The conjugates were characterized by their side chain contents, T(1) relaxivity (r(1)), stability, and in vitro cytotoxicity. High stability and relaxivity of these conjugates coupled with low toxicity show their potential for monitoring the in vivo fate of HPMA-based drug delivery systems by magnetic resonance imaging techniques.