Pradeep Mishra

CNS depressant and anticonvulsant activities of some novel 3-[5-substituted 1,3,4-thiadiazole-2-yl]-2-styryl quinazoline-4(3H)-ones.

A series of new 3-[5-substituted phenyl-1,3,4-thiadiazole-2-yl]-2-styryl quinazoline-4(3H)-ones were synthesized and evaluated for anticonvulsant, sedative-hypnotic and CNS depression activities. After i.p. injection to mice or rat at doses of 30, 100, and 300 mg/kg body weight 2-styryl quinazolin-4(3H)-ones derivatives were examined in the maximal electroshock (MES) induced seizures and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in mice. Rotorod method was employed to determine the neurotoxicity. Out of 18 compounds only 4a, 4e and 4p showed anticonvulsant activity in one or more test models. All except 4l and 4q exhibited significant sedative-hypnotic activity via actophotometer screen. Forced swim pool method to determine CNS depressant activity resulted in some potent compounds. It can be concluded that synthesized compounds exhibited better sedative-hypnotic and CNS depressant activities than anticonvulsant activity.

Synthesis, anticonvulsant and CNS depressant activity of some new bioactive 1-(4-substituted-phenyl)-3-(4-oxo-2-phenyl/ethyl-4H-quinazolin-3-yl)-urea

Several new 1-(4-substituted-phenyl)-3-(4-oxo-2-phenyl/ethyl-4H-quinazolin-3-yl)-urea were synthesized and screened for anticonvulsant, CNS depressant and sedative-hypnotic activity in the mice. After i.p. injection to mice at doses of 30, 100, and 300 mg/kg body weight synthesized compounds were examined in the maximal electroshock induced seizures (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in mice. Spectroscopic data and elemental analysis were consistent with the newly synthesized compounds. The neurotoxicity was assessed using the rotorod method. Compounds E1, E6, E9, E12, P3, P4 and P6 were found to be active in the MES screen whereas E1, P4, P6 and P11 were found to be active in the scPTZ screen. All except E6, E11 and P6 showed more than 50% decrease in locomotor activity at 1h of compound administration via actophotometer screen. CNS depressant activity screened with the help of the forced swim method resulted into some potent compounds. All the compounds were found to exhibit potent CNS depressants activity as indicated by increased immobility time. It can be concluded that newly synthesized compounds possessed promising CNS activities.

An insight on hyaluronic acid in drug targeting and drug delivery

Hyaluronic acid (HA) has recently been studied for its use in drug delivery applications. Medically, HA is used as a surgical aid in ophthalmology. It also possesses therapeutic potential in the treatment of arthritis and wound healing. HA-binding receptors, CD44 and receptor for hyaluronan-mediated motility have attracted much enthusiasm, mainly because they are believed to be involved in cancer metastasis. This review unravels the role of HA in drug delivery and targeting. Designing of various novel drug delivery systems using HA as a biopolymer will also be reviewed in the present article.

Preparation and characterization of HA–PEG–PCL intelligent core–corona nanoparticles for delivery of doxorubicin

The objective of the present study was to synthesize core–corona nanoparticles of doxorubicin (DOX) using hyaluronic acid–polyethyleneglycol–polycaprolactone (HA–PEG–PCL) copolymer for tumor targeting. Targeting efficiency of HA–PEG–PCL nanoparticles was compared with non-HA-containing nanoparticles (methoxy poly ethylene glycol (MPEG)–PCL). The copolymers were chemically synthesized and characterized by IR and NMR spectroscopies. The nanoparticles were characterized for shape and morphology by transmission electron microscopy, particle size, percentage of drug entrapment, and in vitro drug release profile. Differential scanning calorimetry and X-ray diffraction studies were also performed to appraise the crystalline or amorphous nature of DOX inside the polymer matrix. Formulations were prepared using different DOX:polymer ratios (1:1–1:3 w/w) and the optimum formulation with the drug:polymer ratio of 1:1 showed the mean particle size of 95 ± 5 nm and entrapment efficiency of 95.56% in the case of HA–PEG–PCL nanoparticles, while the values were 115 nm and 95.50%, respectively, in the case of MPEG–PCL nanoparticles. The HA–PEG–PCL nanoparticles could release DOX for up to 17 days, whereas the MPEG–PCL nanoparticles could release it for up to 14 days. The hemolytic toxicity and hematological studies confirmed that both DOX-loaded HA–PEG–PCL and MPEG–PCL nanoparticles were safe and suitable for sustained and targeted drug delivery. The tissue distribution study and tumor growth inhibition were performed after intravenous injection of nanoparticles in Ehrlich ascites tumor (EAT)-bearing mice. The nanoparticles of HA–PEG–PCL copolymer accomplishes efficient delivery of DOX in EAT tumor when compared with the MPEG–PCL nanoparticles by the process of receptor-mediated endocytosis, as well as enhanced permeability and retention effect.

Synthesis and antimicrobial activity of some new 3–[5-(4-substituted) phenyl-1,3,4-oxadiazole-2yl]-2- styrylquinazoline-4(3H)-ones

Several 3-[5-(4-substituted)phenyl-1,3,4-oxadiazole-2-yl]-2-styryl quinazoline-4(3H)-one were synthesized and screened for antibacterial activity against Staphylococcus aureus , Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli and antifungal activity against Aspergillus niger and Fusariumoxysporum by the serial dilution technique. Compounds were prepared by reacting corresponding 2-methtyl quinazolinone and 4-subustituted benzaldehydes in glacial acetic acid. Physicochemical and spectral data were consistent with newly synthesized compounds. The prepared compounds were compared with previously synthesized 2-methyl-3-[5-(4-substituted)phenyl-1,3,4-oxadiazole-2-yl]-quinazoline-4(3H)-ones for antimicrobial activity. The present study revealed that styryl moiety at the second position of 4(3H) quinazolinone marginally increased the biological activity and exhibited better antibacterial than antifungal activities.

Synthesis of Novel 2,5‐Disubstituted 1,3,4‐Thiadiazoles for Their Potential Anticonvulsant Activity: Pharmacophoric Model Studies

A series of novel N1‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N4‐(4‐substituted benzaldehyde)‐semicarbazone 1–12, N1‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N4‐[1‐(4‐substituted phenyl)ethanone]‐semicarbazone 13‐16, and N1‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N4‐[1‐(4‐substituted phenyl) (phenyl) methanone]‐semicarbazone 17–20 were synthesized for their anticonvulsant activity. The chemical structures of the compounds were proved by elemental and spectral (IR, 1H‐NMR, 13C‐NMR, and MS) analysis. The anticonvulsant potential of the compounds was investigated using maximal electroshock seizure (MES) and subcutaneous pentylenetrtrazole (scPTZ) models. Compound 19 was found to possess significant anticonvulsant activity in both the models employed for anticonvulsant evaluation. Compounds 8, 13, 15, and 16 also demonstrated a marked anticonvulsant property. The results of the present study validated that the pharmacophore model with four binding sites is essential for anticonvulsant activity. The efforts were also made to establish structure‐activity relationships among the synthesized compounds.

Long circulating PEGylated poly(d,l-lactide-co-glycolide) nanoparticulate delivery of Docetaxel to solid tumors

Purpose: The aim of this study was to investigate the ability of PEGylated poly(d,l-lactide-co-glycolide) nanoparticles (NPs) to deliver Docetaxel (DTX) (an anticancer agent) to solid tumors. Methods: PLGA–mPEG diblock copolymers were synthesized by ring opening polymerization reaction and characterized by 1H NMR, FT-IR and gel permeation chromatography. NPs, with a smooth spherical shape and near 100 nm size were prepared using the emulsion solvent evaporation technique and characterized. The drug release rate was investigated in acidic and physiological media (phosphate buffer saline, pH 5.0 and 7.4). The therapeutic efficacy and biocompatibility of NP formulations were evaluated for in vitro cytotoxicity by MTT assay using MCF-7 and C26 cell lines. The pharmacokinetic and biodistribution studies were performed on C26 tumor bearing mice. The antitumor efficacy of DTX NP formulations on C26 tumor bearing mice was investigated. Results: DTX-loaded PEGylated NPs increased the drugs biological half-life while providing substantial accumulation at the solid tumors. PEGylated NPs appear to be a promising alternate carrier for DTX having greater efficacy in inhibiting tumor growth.

Development and characterization of hyaluronic acid decorated PLGA nanoparticles for delivery of 5-fluorouracil

The present investigation was aimed to develop and explore the prospective of engineered PLGA nanoparticles as vehicles for targeted delivery of 5-fluorouracil (5-FU). Nanoparticles of 5-FU-loaded hyaluronic acid-poly(ethylene glycol)-poly(lactide-co-glycolide) (HA-PEG-PLGA-FU) copolymer were prepared and characterized by FTIR, NMR, transmission electron microscopy, particle size analysis, DSC, and X-ray diffractometer measurement studies. The nanoparticulate formulation was evaluated for in vitro release, hemolytic toxicity, and hematological toxicity. Cytotoxicity studies were performed on Ehrlich ascites tumor (EAT) cell lines using MTT cell proliferation assay. Biodistribution studies of 99mTc labeled formulation were conducted on EAT-bearing mice. The in vivo tumor inhibition study was also performed after i.v. administration of HA-PEG-PLGA-FU nanoparticles. The HA conjugated formulation was found to be less hemolytic but more cytotoxic as compared to free drug. The hematological data suggested that HA-PEG-PLGA-FU formulation was less immunogenic compared to plain drug. The tissue distribution studies displayed that HA-PEG-PLGA-FU were able to deliver a higher concentration of 5-FU in the tumor mass. In addition, the HA-PEG-PLGA-FU nanoparticles reduced tumor volume significantly in comparison with 5-FU. Thus, it was concluded that the conjugation of HA imparts targetability to the formulation, and enhanced permeation and retention effect ruled out its access to the non-tumor tissues, at the same time favored selective entry in tumors, thereby reducing the side-effects both in vitro and in vivo.

Benzimidazole: a promising pharmacophore

The aim of this review is to provide an overview on diverse pharmacological activities of the benzimidazole moiety. This review highlights recent reports of antimicrobial, anticancer, antiviral, antiparasitic, antihypertensive as well as anti-inflammatory activities of the benzimidazoles. The purpose of this review is to collate the literature work reported by researchers on benzimidazole for its various pharmacological activities and also report recent efforts made on this moiety.

Synthesis, antibacterial and antifungal activity of some novel 3-[5-(4-substituted phenyl) 1,3,4-thiadiazole-2-yl]-2-styryl quinazoline-4(3H)-ones

A series of novel 3-[5-substituted phenyl-1,3,4-thiadiazole-2-yl]-2-styryl quinazoline-4(3H)-ones were synthesized and evaluated for antibacterial activity against pathogenic strains of Staphylococcus aureus (MTCC no. 96), Bacillus subtilis (MTCC no. 619), Pseudomonas aeruginosa (MTCC no. 424) and Escherichia coli (MTCC no. 40) and antifungal activity against Aspergillus niger, Candida albicans and Fusarium oxysporum. The cup-plate method was employed to determine the minimum inhibitory concentration (MIC) value of the compounds. Some of the compounds exhibited activity comparable to Norfloxacin. The present report reveals that synthesized 2-styryl-quinazoline-4(3H)-one exhibited better antibacterial than antifungal activity.