In this review, classification of drugs, chemical structure, and biological activity, examples of pharmacological activities of some structural moieties, bioisosterism, physicochemical properties in relation to drug action, drug-receptor theory, acid-base chemistry in formulation and biodistribution of the drug, quantitative structure-activity relationship, and molecular docking are briefly presented with examples.

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Background and objective As no literature was traced dealing with the volatile constituents of the leaves or the seeds of Arctium lappa L., it was deemed of interest to carry out a gas chromatography/mass spectrometry (GC/MS) analysis and antimicrobial activity study of the volatile constituents of roots, leaves, and seeds of the plant grown in Egypt. Materials and methods The volatile constituents of the roots, leaves, and seeds were analyzed by GC/MS. The antimicrobial activity was tested using the agar well diffusion technique. Results and conclusion GC/MS of the volatile constituents from the leaves showed 19 identified compounds, the major being caryophyllene oxide (54.2%), followed by β-elemene (6.2%) and β-costol (4.0%). Analysis of the volatile constituents of the roots revealed 14 identified compounds, the major being caryophyllene oxide (51%), followed by aromadendrene (16%) and isoaromadendrene epoxide (6.4%). Analysis of the volatile constituents of the seeds revealed 22 identified compounds, the major being E-citral (28.8%), followed by geraniol (20.3%) and Z-citral (9.5%). The volatile constituents of the leaves and roots exhibited moderate antimicrobial activity against bacteria and significant antifungal activity, in comparison with the standards used, whereas the volatile constituents of the seeds showed moderate antimicrobial activity against bacteria and fungi.

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Objective The aim of the present work was to study the production of tropane alkaloids by in vitro cultures of Atropa belladonna L. and to evaluate the anticonvulsant, antinociceptive, motor incoordination, and antioxidant activities of both in vitro and original plant extracts. Background A. belladonna is a very important medicinal plant with multipurpose therapeutic effects. The yield of its alkaloid content is very low, which makes it difficult for industrial application. Materials and methods Murashige and Skoog media were used for callus and plant differentiation induction from leaf explants of A. belladonna L. Qualitative and quantitative analysis of alkaloids was carried out using high-performance liquid chromatography. The anticonvulsant activity was screened by the pentylenetetrazole seizure test. The antinociceptive activity was evaluated by adopting the writhing test, whereas motor incoordination was evaluated using the rotarod test. In addition, antioxidant activity was estimated using the 2,2'-diphenyl-1-picrylhydrazyl radical-scavenging test. Results Callus and differentiated plants were successfully induced in Murashige and Skoog media supplemented with growth regulators. High-performance liquid chromatography analysis revealed the production of higher concentrations of tropane alkaloids in differentiated plants than in the original plant. Anticonvulsant and antinociceptive activities, motor incoordination, and the antioxidant effect of callus extracts were much higher than those of the original plant leaf extract. Conclusion Plant tissue culture could be considered as an efficient and alternative source of continuous supply of tropane alkaloids with potent anticonvulsant, antinociceptive, motor incoordination, and antioxidant activities. It is also a powerful tool for producing A. belladonna strain with a high tropane alkaloid content.

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Background The marine ecosystem has generated considerable interest for the isolation of new microorganisms, especially Streptomyces spp. It is considered a cheaper source of precious enzymes such as collagenase. Objective This study aimed to produce new collagenase enzymes from the locally isolated marine Streptomyces spp. grown on marine wastes for application in industrial fields. Materials and methods The marine isolate was identified as Nocardiopsis dassonvillei NRC2aza by 16S rDNA sequencing. N. dassonvillei NRC2aza was grown on basal medium composed of whole chitin wastes as the sole C and N source for the production of collagenase enzyme. Extraction of the enzyme was performed to study its characteristics. Results and conclusion Maximum collagenase activity (240 U/ml) was obtained after 6 days of incubation in shaken liquid cultures when whole chitin wastes (shrimp and crab wastes) were used as the sole nitrogen and carbon source. A N. dassonvillei NRC2aza isolate was shown to produce significant amounts of collagenase, reaching 1872 U/g, under solid-state fermentation using a mixture of 10 g chitin waste and 2 g of feather. Successive ammonium sulfate fractionation of N. dassonvillei NRC2aza growth extract produced a group of collagenases with different molecular weights. The 80% enzyme fraction was the most active and possessed the highest collagenase activity (1106.66 U/f), reaching about 3.8-fold that of the culture filtrate. The optimum pH and temperature were 8 and 55°C, respectively, and the enzyme was stable at pH range of 6-8. The collagenase exhibited heat stability for 60 min at 50°C. Therefore, collagenases can be applied in food industry as tenderizers of red meat and in fur and hide tanning to ensure uniform dyeing of leather.

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Background The isolation of the locally marine Nocardiopsis dassonvillei NRC2aza was characterized by the exceptional dehairing properties of its subtilisin-like keratinase. Objectives The aim of this work was to extract keratinase enzyme from the marine Nocardiopsis dassonvillei NRC2aza to be an alternative to sodium sulphide, which is the major pollutant from tanneries. Its unique nonactivity on collagen enhances its industrial potential. Material and methods Fermentation of the marine isolate Nocardiopsis dassonvillei NRC2aza on whole-feather medium was performed for keratrinase enzyme production. Extraction of the enzyme was carried out by solid-state fermentation (SSF). Results and conclusion Nocardiopsis dassonvillei NRC2aza have excellent characteristics of crude keratinase, producing 1680 U/ml in a shaking submerged culture (SmF) and 19 760 U/g using SSF after 4 days at pH 7. The effect of inoculum concentration on SSF was studied, whereby higher concentrations (150-200%) lowered the activity. Fractional precipitation of the enzyme by ammonium sulphate produced four fractions, of which 70% was the most active and produced remarkable hide dehairing. A new locally isolated Streptomyces spp. from marine ecosystem produced a highly active keratinase enzyme that exhibits remarkable hide dehairing.

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Aim This study is an attempt to explore the biological activities of isolated endophytic bacteria from marine sources that were coded A1, A2, and A3 (Padina pavonica), A4 (Cystoseira myrica), A5 (Acanthophora dendroides), and A6 (Sargassum sabrepandum). The bacteria coded C1, C2, and C3 were isolated from the soft coral Nephthea mollis and S1 and S2 were isolates from the sponge Hymedesmia spp. The primary aim of the study was the identification of active compounds. Materials and methods The bioactive compounds were extracted using ethyl acetate from nutrient broth media; biological activities of the extracted metabolites and 16S rDNA identification of the most promising isolate were studied. The eight major fractions of the extract showed different composition patterns when identified by liquid chromatography/mass spectrometry analyses. Results and conclusion Agar diffusion assay showed inhibitory activities of A4 extracts against the growth of most pathogenic microorganisms. Identification using PCR 16S rDNA and electrophoresis confirmed 98% identity to the Enterobacter cloacae strain GH1 (ac: JF261136.1). Eight compounds out of fifteen in the extract were identified as diketopiperazine derivatives. The maximum growth of E. cloacae was obtained at 30°C, pH 7, with the addition of maltose and KI to the media. The free radical scavenging activity exhibited good antioxidant activity (72.19%, IC ₅₀ = 1.266 mg/ml) on using 2.0 mg/ml of the crude extract. The extract showed a high antiviral activity towards Newcastle disease virus and avian influenza virus A(H5N1).

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Background Meningococcal disease caused by Neisseria meningitidis is a widely distributed complex human disease affecting all age categories. Successful and effective treatment of patients with this disease depends on precise and early diagnosis of the disease. Objective The aim of this study was to evaluate the possible use of direct PCR (D-PCR) for the detection and amplification of N. meningitidis DNA in blood samples compared with the conventional PCR (C-PCR) method, which needs bacterial culture and DNA extraction. Materials and methods Specific primers on the basis of the 16S rDNA of N. meningitidis were used for the amplification of 600 bp DNA fragment. Two strategies were followed: D-PCR, which relies on amplification of DNA directly in blood without DNA extraction using the KAPA Blood PCR Kit, and the C-PCR, which relies on the extraction of bacterial DNA using the Qiagen QiAmp DNA Mini Kit. The following blood samples were included in each strategy: A blood sample with bacterial cerebrospinal meningitis confirmed by blood culture, a normal blood sample seeded with N. meningitidis ATCC (13090) reference strain as positive control for the standardization of the PCR procedure, a normal blood sample as a negative control, and an internal negative control test sample (H ₂ O). Results Both D-PCR and C-PCR tests gave the expected amplified DNA fragment of 600 bp on agarose gel electrophoresis of both patients' blood sample and N. meningitidis seeded normal blood sample, whereas no amplified products were detected when both tests were performed on normal blood sample or the internal negative H ₂ O control. Conclusion Direct blood PCR assay could be a possible easy, rapid, nonexpensive, and specific method for the detection of meningococci in blood samples, particularly in situations in which culture is difficult because of previous treatment, and also could facilitate the large-scale screening of various medical conditions.

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Background and objectives Selenophene moiety is one of the heterocyclic compounds with a selenium atom that plays a vital role in biological fields such as antioxidant, antidepressant, anticonvulsant, antimicrobial, and anticancer activities. The aim of this study was to describe the synthesis of some new heterocycles derived from 2-amino-4-(1-benzoylindol-3-yl)selenophene-3-carbonitrile derivatives and to evaluate their 2,2Ͳ-diphenyl-1-picrylhydrazyl radical-scavenging activity. Materials and methods 2-Amino-4-(1-benzoylindol-3-yl)selenophene-3-carbonitrile ( 3 ) was prepared and allowed to react with each of formic acid, formamide, carbon disulfide, urea, thiourea, malononitrile, or ethyl cyanoacetate to yield selenolo[2,3-d]pyrimidines 4-7 and selenolo[2,3-b]pyridine derivatives 8 and 9 , respectively. Moreover, reaction of compound 3 with hydrochloric acid or acetic anhydride in glacial acetic acid yielded selenolo[2,3-d]pyrimidin-4-one 10 and selenoacetamide derivative 11 , respectively. In contrast, reaction of Schiff base 12 with thioglycolic acid, phenacyl bromide, or chloroacetyl chloride yielded thiazolidine 13 and azidatine derivatives 14 and 15 , respectively. Reaction of compound 3 with some substituted benzenesulfonyl chlorides yielded sulfonamide derivatives 16a, b, c , respectively. Moreover, 2-amino-1,3,4-thiadiazole 19 and 4-oxo-2-iminothiazolidine derivatives 21 were prepared through cyclization of hydrazinecarbothioamide 18 or chloroacetamido derivative 20, respectively. The fusion of 3 with succinic anhydride yielded pyrrolidine-2,5-dione 23 , whereas heating of 3 with succinic anhydride in ethanol yielded succinamic acid derivative 24 . The newly synthesized compounds were screened for their 2,2Ͳ-diphenyl-1-picrylhydrazyl radical-scavenging activity. Results and conclusion Compound 8 showed promising activity with a radical-scavenging effect (IC ₅₀ ) of 166.40 μg/ml compared with ascorbic acid (an IC ₅₀ of 129.64 μg/ml) as a reference standard.

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Introduction and purpose Magnetic Fe ₃ O ₄ -chitosan (CS) nanoparticles are prepared by the coagulation of an aqueous solution of CS with Fe ₃ O ₄ nanoparticles. Various factors such as time, elevated pH and temperatures affecting magnetic Fe ₃ O ₄ -CS nanoparticles were studied using the immobilization technology. To improve the efficient use of lipase and reduce the cost of production, enzyme immobilization technology is applied. Materials and methods Fe ₃ O ₄ nanoparticles were prepared by the coprecipitation method. The CS solution was prepared by dissolving 0.5 g of CS in 50 ml of 1% (v/v) acetic acid, followed by the addition of 12.5 ml of 1 mg/ml Tripolyphosphate (Tpp) solution as a cross-linker to enhance colloidal stability. The solution was used to resuspend the magnetic Fe ₃ O ₄ nanoparticles. The resulting Fe ₃ O ₄ -CS was stored at 4°C until use. Uncoated and coated magnetite nanoparticles for immobilizing the lipase were characterized according to the particle size, as measured by atomic force microscopy or scanning force microscopy using contact mode by means of Agilent 5500. The infrared spectra were detected by a Fourier-transform infrared spectrophotometer. Results and conclusion To solve leaching problems of the adsorbed lipase and improve the conventional method of lipase immobilization, different concentrations of CS were used. A concentration of CS nanoparticles of 0.3 mg was proved to be more suitable, with an immobilization efficiency of 95.6%. On the basis of atomic force microscopy three-dimensional images, the diameters of the uncoated magnetite particles were determined to be 12 nm. The immobilized lipase shows better operational stability, including wider pH and thermal ranges. The pH optimum of the immobilized enzyme exhibited an acidic shift (pH 5-6). The immobilized lipase was stable in the pH range from 3 to 5 as compared with free lipase. Lipase immobilized by Fe ₃ O ₄ -CS nanoparticles remained fully active up to 40°C. At a temperature of 60°C, free lipase preserved about 40% of its residual activity for 1 h; however, the immobilized enzyme preserved about 72.9% of its residual activity at the same time. The kinetic constants V_max and K_m were determined to be 250 U/mg protein and 20 mmol/l, respectively, for immobilized lipase. The resulting immobilized lipase had better resistance to pH and temperature inactivation compared with free lipase and exhibited good reusability; after eight repeated uses, the immobilized lipase retained over 63.5% of its original activity.

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Background and objectives Antimutagenic or protective effects have been attributed to many classes of phytocompounds, mainly flavonoids and phenolic compounds, present in foods. Anticancer, antioxidant and anti-inflammatory activities of Khaya spp. have been reported, but their desmutagenic and antimutagenic activities were not studied. The aim of this study was to identify the phenolic contents of Khaya grandifoliola and correlate the desmutagenic and antimutagenic activities of these compounds. Materials and methods Desmutagenic and antimutagenic activities of specimen extracts of K. grandifoliola leaves and flowers were evaluated by measuring the inhibition of Salmonella typhimurium TA100 His ⁺ revertants induced by ethyl methanesulphonate and ribose lysine. The phenolic contents of K. grandifoliola leaf extracts were determined using column and paper chromatography. Spectroscopic analysis UV, ¹ H NMR, ¹³ C NMR and electrospray ionization were applied to identify the isolated compounds. Results and conclusion Five phenolic compounds were isolated for the first time from K. grandifoliola leaves. These compounds were identified as quercetin 3-O-rhamnoglucoside (rutin), quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, quercetin and 6-methoxycoumarin-7-O arabinofuranoside. The alcoholic extracts of both leaves and flowers (total and successive) of K. grandifoliola, rutin and quercetin rhamnoside isolated from the leaves, exhibited desmutagenic and antimutagenic activity against ethyl methanesulphonate-induced and ribose lysine-induced reversion.

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Purpose This study investigated total ethanol and successive extracts of Brassica oleracea L. var. Italica inflorescences for their prophylactic and therapeutic effects on rat's liver using the paracetamol-induced hepatotoxicity method. The present investigation focuses on liver histopathological analysis and evaluation of biochemical parameters. Materials and methods Hepatoprotective activity of B. oleracea L. var. Italica was evaluated using the paracetamol-induced hepatotoxicity method on rat's liver. Phytochemical investigation of 80% ethanolic extract was performed using column chromatography and preparative thin layer chromatography. Spectroscopic analyses UV, ¹ H-NMR, and ¹³ C-NMR together with Electron impact mass spectrum (EIMS) were carried out to identify isolated compounds. Results Treatment with total ethanol and different successive extracts of B. oleracea showed a significant decrease in the liver enzymes (aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) when paracetamol was administered before the extracts (therapeutic) or administered after the extracts (prophylactic). On examination of the histopathological results, it is obvious that the prophylactic activity of the extracts was more effective. From ethanol extract, obtucarbamate, N-(4-hydroxy phenyl) acetamide, and p-hydroxy benzoic acid were isolated using chromatographic methods. The isolated compounds were identified through spectroscopic analysis and compared with literature reports. Conclusion Broccoli extracts were studied intensively for their prophylactic and therapeutic effects on rat's liver damage induced by paracetamol. The evaluation of biochemical parameters and histopathological analysis showed that broccoli extracts have prophylactic activity against liver damage. Phytochemical investigation of 80% ethanolic extract resulted in isolation of three compounds, obtucarbamate, N-(4-hydroxy phenyl) acetamide, and p-hydroxy benzoic acid, and can be considered a good candidate for the protection of liver damage induced by paracetamol.

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Background and objectives Heterocyclic systems with a pyrimidine nucleus display a wide spectrum of biological activities, such as antimicrobial, antiviral, anticancer, antidepressive, anti-inflammatory, antitubercular, diuretic, and anticoagulant. The aim of the present study was the synthesis of new heterocyclic sulfanylpyrimidin-4(3H)-one derivatives by adopting simple and efficient methods, in addition to ethyl-2-(pyridin-4-yl) methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives in excellent yields. Materials and methods The synthesis of the titled sulfanyl pyrimidin-4(3H)-one derivatives was achieved by the reaction of compounds 1a-c with phenacyl bromide, 4-methyl phenacyl bromide, or 4-nitrophenacyl bromide to give 5-(morpholin-4-ylmethyl)-2-oxoethylphenyl-sulfanyl-pyrimidin-4(3H)-ones (2a-c), [(4-methylpiperazin-1-yl) methyl]-2-oxoethylphenyl-sulfanyl-pyrimidin-4(3H)-ones (3a-c), or piperidin-1-yl) methyl]sulfanyl-pyrimidin-4(3H)-ones (4a-c), respectively. In addition, several heterocyclic pyrimidine derivatives such as ethyl-2-((pyridin-4-yl)methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives 6a-h were prepared by the reaction of 1,2 dihydropyrimidone derivatives 5a-h with picolyl chloride using conventional and heterogeneous catalysts such as silica sulfuric acid and CuY-Zeolite. The structures of the synthesized compounds were confirmed by elemental analyses and spectroscopic methods. Results and conclusion A simple and efficient method was used for the synthesis of sulfanyl pyrimidin-4(3H)-one derivatives through reaction with different reagents. Also, ethyl-2-((pyridin-4-yl)methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives were obtained using conventional and heterogeneous conditions in excellent yields.

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Background and objective This work embraced a systematic search for potentiated methodologies for peptide synthesis through a di-dimensional approach for convenient synthesis of the nonapeptide (B ₂₂ -B ₃₀ ) of porcine insulin B-chain. Liquid-phase peptide synthesis (LPPS) and liquid-solid-phase peptide synthesis (modified SPPS) were used for the synthesis of this active part. Materials and methods A nonapeptide Arg-Gly-Phe-Phe-Tyr-Thr-Pro-Lys-Ala-OH corresponding to B ₂₂ -B ₃₀ of porcine insulin B-chain was synthesized using different methods: LPPS and modified SPPS. Time consumption, yield and purity of all products using the different methods were compared with each other. Results and conclusion The results indicated that modified SPPS is advantageous, as it consumes less solvent per coupling and deprotection reaction, thereby reducing operating costs and solvent waste. Reducing side reactions result in racemization, cyclization or premature peptide formation. Modified SPPS produces peptides with yields and purity better than LPPS. Also, it can reduce the time of coupling and deprotection reactions.

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