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1.
The incidence of skin cancers such as non-melanoma skin cancer and malignant melanoma has increased in the last few years mainly because of chronic exposure to ultraviolet (UV) radiation. Sunscreens protect the skin against harmful UV radiations; however, some limitations of these products justify the discovery of new UV filters. Novel 1,3,5-triazine derivatives (12a-h) obtained by the optimization of prototype resveratrol were synthesized and characterized. All compounds exhibited sun protection factor (SPF) and UVA protection factor (UVAPF) in the range of 3–17 and 3–13, respectively. These values were superior to resveratrol and the UV filter ethylhexyl triazone (EHT) currently available on the market. In addition, all compounds demonstrated in vitro antioxidant activity and thermal stability with the decomposition at temperatures above 236 °C. In conclusion, the novel 1,3,5-triazine derivatives have emerged as new UV filters with antioxidant effect useful to prevent skin cancer.  相似文献   

2.
《Journal of plant physiology》2014,171(16):1545-1553
The effects of PAR and UV radiation and subsequent responses of certain antioxidant enzymatic and non-enzymatic defense systems were studied in a rice field cyanobacterium Anabaena siamensis TISTR 8012. UV radiation resulted in a decline in growth accompanied by a decrease in chlorophyll a and photosynthetic efficiency. Exposure of cells to UV radiation significantly affected the differentiation of vegetative cells into heterocysts or akinetes. UV-B radiation caused the fragmentation of the cyanobacterial filaments conceivably due to the observed oxidative stress. A significant increase of reactive oxygen species in vivo and DNA strand breaks were observed in UV-B exposed cells followed by those under UV-A and PAR radiation, respectively. The UV-induced oxidative damage was alleviated due to an induction of antioxidant enzymatic/non-enzymatic defense systems. In response to UV irradiation, the studied cyanobacterium exhibited a significant increase in antioxidative enzyme activities of superoxide dismutase, catalase and peroxidase. Moreover, the cyanobacterium also synthesized some UV-absorbing/screening substances. HPLC coupled with a PDA detector revealed the presence of three compounds with UV-absorption maxima at 326, 331 and 345 nm. The induction of the biosynthesis of these UV-absorbing compounds was found under both PAR and UV radiation, thus suggesting their possible function as an active photoprotectant.  相似文献   

3.
A simple and convenient one-pot four-component synthesis of morpholine-connected pyrazolidine derivatives 2af and 4af was developed using direct metal-free catalysis, with the identities of the synthesized compounds confirmed by IR, NMR (1H and 13C), mass spectrometry, and elemental analysis. The prepared compounds were inspected for antimicrobial, antioxidant, and cytotoxic activities.Antimicrobial and antifungal activities against five bacterial and four fungal pathogens, respectively, were investigated using the disc diffusion technique. In antibacterial activity, compounds 2d and 2f (MIC = 2 μg/mL) exhibited significantly higher activity than the standard ciprofloxacin. The results of antifungal assay showed that the activity of compound 4a (MIC = 0.5 μg/mL) was significantly higher than the standard clotrimazole. Antioxidant activity was screened based on ABTS+ radical scavenging and linoleic acid peroxidation performance. Compound 4a showed substantial antioxidant (91.3%) activities, as compared with the Trolox standard. Cytotoxicity was evaluated using HepG2 (liver), HeLa (cervical), and MCF-7 (breast) cancer cell lines, with high toxicities observed for 2b (GI50 = 12.2 μm) and 4a (GI50 = 07.8 μm).  相似文献   

4.
4-Schiff base-7-benzyloxy-coumarins 5a(1)-5h(2) and its derivative 6 were designed and synthesized based on the 7-benzyloxy-coumarin structure as novel antioxidants. The in vitro antioxidant activities screening revealed that 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of compounds 5b(1), 5d(1), 5f(1), 5f(2), 5g(1) and 5g(2), and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) cation (ABTS(+)) radical scavenging activities of compounds 5a(1), 5b(1), 5c(1), 5c(2), 5d(1), 5e(1), 5e(2), 5f(2), 5g(1), 5g(2) and 5h(1) were better than that of the commercial antioxidant butylated hydroxytoluene (BHT), while the superoxide anion radical scavenging activities of 5a(2) and 5g(2) were stronger than that of the commercial antioxidant butylated hydroxyanisole (BHA), and the hydroxyl radical scavenging activity of 5e(1) was much better than that of the common antioxidant ascorbic acid.  相似文献   

5.
A new series of N-acylhydrazone derivatives of 2-mercaptobenzimidazole (2-MBI) has been synthesized through S-alkylation with 1-bromotetradecane and N-alkylation with ethyl-2-chloroacetate. The resulting ester was synthetically modified through hydrazine hydrate to acyl hydrazide which was condensed with aromatic aldehydes to afford the title N-acylhydrazones (4-17). Chemical structures of the newly synthesized compounds have been confirmed through mass, FT-IR and 1HNMR techniques. In vitro free radical scavenging and α-glucosidase inhibition activities of the compounds were investigated with reference to the standard ascorbic acid and acarbose, respectively. Amongst the target compounds, 13 showed the highest inhibition in DPPH scavenging assay (IC50 = 131.50 µM) and α-glucosidase inhibition potential (IC50 = 352 µg/ml). We extended our investigations to explore the mechanism of enzyme inhibition and conducted docking analysis by using Molecular Operating Environment (MOE 2016.08). A homology model for α-glucosidase was constructed and validated using Ramachandran plot. Docking studies were also carried out on human intestinal α-glucosidases. In view of the importance of the nucleus involved, the synthesized compounds might find extensive medicinal applications as reported in the literature.  相似文献   

6.
A novel series of tacrine derivatives containing sulfonamide group were synthesized and their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were evaluated. The result showed that all the synthesized tacrine-sulfonamides (VIIIa–o) exhibited inhibitory activity on both cholinesterases. VIIIg showed the highest inhibitory activity on AChE IC50 = 0.009 μM. This value is 220-fold greater than that of galantamine (IC50 = 2.054 μM) and 6-fold greater than tacrine (IC50 = 0.055 μM). VIIIf displayed the strongest inhibition of BuChE (IC50 = 2.250 μM), which is close to donepezil (IC50 = 2.680 μM) and 8-fold greater than that of galantamine (IC50 = 18.130 μM) Furthermore, all of the synthesized tacrine derivatives showed higher inhibition of BuChE than that of galantamine. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were investigated for the antioxidant activity. Among them, VIIIb (IC50 = 94.390 ± 2.310 μM) showed significantly better ABTS cation radical scavenging ability than all of the new synthesized compounds.  相似文献   

7.
A series of 2-arylbenzimidazole derivatives (3a3p and 4a4i) were synthesized and evaluated as potential antioxidant and antimicrobial agents. Their antioxidant properties were evaluated by various in vitro assays including hydroxyl radical (HO) scavenging, superoxide radical anion (O2?) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, and ferric reducing antioxidant power. Results demonstrated that compounds with hydroxyl group at the 5-position of benzimidazole ring had a comparable or better antioxidant activity in comparison to standard antioxidant tert-butylhydroquinone (TBHQ). Markedly, compound 4h that showed the highest HO scavenging activity (EC50 = 46 μM) in vitro had a significant reduction of 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced intracellular oxidative stress and H2O2-induced cell death. In addition, these compounds showed moderate to good inhibitory activity against Staphylococcus aureus selectively at noncytotoxic concentrations.  相似文献   

8.
New chromeno carbamodithioates (7a-i), have been synthesized from 2, 3-dimethyl-7-(oxiran-2-ylmethoxy)-4H-chromen-4-one (5), carbondisulphide and commercially available acyclic and cyclic secondary amines in acetonitrile with good to excellent yields. The free radical scavenging activity of novel chromone-carbamodithioate analogues was quantitatively estimated by spectrophotometric method. Whereas, molecular docking studies were performed with the active site of cyclooxygenase-2 to identify hydrogen bonding, hydrophobic and ionic interactions between protein and ligands. The compounds 7g and 7h demonstrated potent antioxidant activity with IC50 of 1.405 ± 0.019 mM and 1.382 ± 0.35 mM respectively compared to Ascorbic acid.  相似文献   

9.
Some thiazolyl hydrazones were synthesized by one pot reaction of thiophene-2-carbaldehyde or 2, 4-dichlorobenzaldehyde, thiosemicarbazide and various phenacyl bromides which were preliminarily screened for in vitro antioxidant and antifungal activities. Excellent DPPH and H2O2 radical scavenged antioxidant activities were observed with almost all the tested compounds. Compounds 4a, 4b, 4c, 4e, 4f and 4i showed comparable DPPH scavenged antioxidant potential (90.26–96.56%) whereas H2O2 scavenged antioxidant activity (90.98–92.08%) was noticeable in case of 4a and 4f; showing significant antioxidant potential comparable with the standard ascorbic acid (95.3%). In vitro antifungal activity of synthesized compounds against fungal species Candida albicance, Aspergillus niger and Aspergillus flavus was found to be moderate to good as compared with the standard fluconazole and MIC values were found in the range of 3.12–25 μg/mL. Molecular docking studies revealed that the compounds 4a, 4b and 4c have a potential to become lead molecules in drug discovery process. In silico ADMET study was also performed for predicting pharmacokinetic and toxicity profile of the synthesized antioxidants which expressed good oral drug like behaviour and non-toxic nature.  相似文献   

10.
Preparation of dopamine derivatives was carried out as a response to the increasing demand for new lipophilized antioxidants in food, cosmetic and pharmaceutical industries. A large series of dopamine esters (DA-C3 to DA-C18:1) with increasing lipophilicity was synthesized using lipase from Candida antarctica (Novozyme 435) as a biocatalyst. The highest conversion yield (52.75%) was reached when caprylic acid (DA-C8) was used as acyl donor. Synthesized compounds were purified and evaluated for their antioxidant activity using the DPPH and the ABTS tests. Results showed that esterification had little effect on radical-scavenging capacity. However, long chain fatty acid esters displayed higher protective effect of oil against oxidation at 70 °C as compared to the parent dopamine or to the BHT. The hemolytic activity of dopamine esters was studied. Middle chain length derivatives (DA-C8 and DA-C12) of dopamine and oleic acid derivative (DA-C18:1) showed the highest hemolytic activity against human erythrocyte. The antimicrobial activities of dopamine esters were also evaluated using well diffusion and minimal inhibition concentration methods. Among all the tested compounds, DA-C8 and DA-C12 exhibited the highest antibacterial activities. These results open up potential applications by using dopamine derivatives as antioxidants and antimicrobial compounds in cosmetic, food and pharmaceutical industries.  相似文献   

11.
Two 2-amino-1,3,4-thiadiazoles containing phenolic hydroxyl groups were combined with different carboxylic acid chlorides giving sixteen amide derivatives with good antioxidant and antiproliferative potential. The compound 3′c with an adamantane ring displayed excellent DPPH radical scavenging activity and good cytotoxic activity against human acute promyelocytic leukemia HL-60 cells, while 1,3,4-thiadiazole 3′h with 4-chlorophenyl moiety was found to be the most effective in inhibition of survival of lung carcinoma A549 cells. All examined thiadiazoles except 3a and 3′a exerted higher cytotoxic activities on A549 and HL-60 cancer cells when compared with normal fibroblasts MRC-5, pointing to selectivity in their antiproliferative action. Some of the most active novel compounds 3c, 3′c, 3′g and 3′h induced significant increase in the percentage of HL-60 cells in the subG1 cell cycle phase in comparison with the control cells. The induction of cell death in HL-60 cells by these compounds was at least partially dependent on activation of caspase-3 and caspase-8. The compounds 3c and 3′c exerted strong antiangiogenic activity. Furthermore, compounds 3c, 3′c, 3′g and 3′h showed the ability to down-regulate the MMP2 and VEGFA expression levels in the treated HL-60 cells when compared with the control cell samples.  相似文献   

12.
In the current investigation, the active principles of the methanol extracts of Rhododendron arboreum leaves (MEL) and flowers (MEF) were investigated with the help of ultra-high performance liquid chromatography (UHPLC), amino acid analyzer and gas chromatography mass spectrometry (GC-MS). UHPLC revealed different polyphenols present in the extracts. GC-MS identified 20 phytochemicals in leaves and 17 in the flowers, whereas, amino acid analyzer confirmed 11 amino acids in leaves and 10 in the flowers. The extracts were subjected to the investigation of biological activity through analysis of antioxidant activity in different in vitro assays, antimutagenic activity in Ames assay and cancer cell growth inhibition activity by MTT (3-4,5 dimethylthiazol-2,5 diphenyltetrazolium bromide) assay. MEL showed higher antioxidant activity in lipid peroxidation inhibition assay (95.32 ± 0.37%) than MEF (77.09 ± 4.17%) with IC50103.6 µg/ml for MEL and 271.17 µg/ml for MEF. In nitric oxide scavenging assay, an activity of 94.46 ± 0.32% (IC50 150.13) was observed in MEF followed by 83.71 ± 0.74% (IC50 179.52) in MEL. The antimutagenic activity of both the extracts was evaluated against sodium azide, 4-nitro-O-phenylenediamine and 2-aminofluorene mutagens in TA-98 and TA-100 strains of Salmonella typhimurium. The analysis was carried out using pre- and co-incubation modes. However, both extracts were observed to possess considerable antimutagenic activity against different known mutagens, flowers came out to be more effective than the leaves in terms of % inhibition. The extracts also exhibited significant cancer cell growth inhibition activity, when tested against 3 cancer cell lines namely, Human cervical cancer cell line (HeLa), Breast cancer cell line (MCF7) and Lung cancer cell line (A549). In case of HeLa and A549, MEL showed higher activity of 64.62 ± 2.65 and 75.08 ± 1.68% as compared to 53.11 ± 2.84 and 45.92 ± 2.43% in MEL, respectively. The EC50 values for MEL in HeLa and A549 were noted to be 232.76 and 155.38 µg/ml, respectively, whereas, MEF had EC50 of 395.50 µg/ml in HeLa and 660.26 µg/ml in A549. Further, MEF showed higher cytotoxicity in MCF7 cell line (84.93 ± 1.17%) followed by the MEL (73.57 ± 1.27%) with EC50 value of 95.16 µg/ml for MEF followed by 172.19 µg/ml for MEL. The biological activities of the extracts can be attributed to the phyto-constituents identified by sophisticated instruments.The biological activities of the extracts can be attributed to the active principles identified by sophisticated instruments.  相似文献   

13.
ObjectiveTo investigate the effect of the ethyl acetate fraction of the aerial parts of E. paralias L. F. Euphorbiaceae on nephroprotective, cytotoxic, and antioxidant.Methodsdifferent spectroscopic and spectrophotometric methods were applied to identify phytoconstituents. The nephroprotective potential of E. paralias ethyl acetate fraction (Ep EtOAc) was evaluated in male rats with thioacetamide-induced kidney injury, as wll as cytotoxic activity was evaluated using a viability assay, and the antioxidant activity was evaluated using the DPPH method. Results: quantitative estimation of total phenolics and flavonoids of E. paralias was performed using unique spectrophotometric methods. The polyphenolic compounds gallic acid (1), ellagic acid (2), kaempferol-3-O-(6″-O-galloyl-β-D-glucopyranoside) (3), quercetin-3-O-β-D-glucopyranoside (4) and quercetin-3-O-β-D-arabinoside (5) were isolated from the ethyl acetate fraction of the aerial parts of E. paralias. The thioacetamide administration resulted in marked nephrotoxicity, but pretreatment with Ep EtOAc significantly attenuated the nephrotoxicity through alteration of kidney biomarkers, thereby improving the redox status of the tissue and restoring serum biochemical parameters nearly to normal levels. This study revealed a significant cytotoxic and strong antioxidant effect. Conclusion: we conclude that the Ep EtOAc may be used in the future as nephroprotective, cytotoxic, and antioxidant agent derived from a natural source.  相似文献   

14.
The novel urea primaquine derivatives 3 were prepared by aminolysis of primaquine benzotriazolide 2 with several hydroxyamines and ethylendiamine, while carbamates 4 were synthesized from the same precursor 2 and alcohols. All compounds are fully chemically characterized and evaluated for their cytostatic and antioxidant activities. The most prominent antiproliferative activity was obtained by compounds 3c, 3d, 3g, and 5b (IC50 = 9–40 μM). 1-(5-Hydroxypentyl)-3-[4-(6-methoxy-quinolin-8-ylamino)-pentyl]urea (3c) showed extreme selectivity toward SW 620 colon cancer cells (IC50 = 0.2 μM) and a bit less toward lung cancer cells H 460. Hydroxyurea 3h showed the highest interaction with DPPH. Primaquine twin drug 3g showed very significant inhibition on LOX soybean (IC50 = 62 μM). Almost all the tested derivatives highly inhibited lipid peroxidation, significantly stronger than primaquine phosphate.  相似文献   

15.
A series of substituted benzimidazole derivatives were synthesized by reacting O-phenylenediamine with various aromatic aldehydes or glycolic acid using various inexpensive reagents in aqueous media. Synthesized compounds were characterized and elucidated by IR, 1H NMR, ESI-MS spectra. Resultant compounds were screened for in vitro antimicrobial, cytotoxic, antioxidant, lipid peroxidation and cholinesterase inhibitory activities, in vivo analgesic and anti-inflammatory, and in silico anti-acetylcholinesterase and anti-butyrylcholinesterase activities. Among the synthesized compounds, compound 3b showed most promising central analgesic effect (46.15%) compared to morphine (48.08%), whereas compounds 6, 3c and 3a showed significant peripheral analgesic activity at two different dose levels (25 mg/kg and 50 mg/kg). Compounds 3b and 3a at the dose of 100 mg/kg showed significant anti-inflammatory effects from the first hour and onward, whereas compounds 6 and 3b showed moderate cytotoxic activities. In addition, compound 3a showed significant antioxidant activity having IC50 value of 16.73 µg/ml compared to 14.44 µg/ml for the standard BHT. Compound 6, 3a and 3b exhibited mild to moderate cholinesterase inhibitory activity. In silico studies revealed that compound 3a and 3b might be suitable for cholinesterase inhibitory activity. A comprehensive computational and experimental data suggested compounds 3b and 3a as the best possible candidates for pharmacological activity. All the experimental data were statistically significant (p < 0.01 level).  相似文献   

16.
17.
In this paper, a series of novel bromophenol derivatives were synthesized and evaluated for their acetylcholinesterase and α-glycosidase enzymes inhibition properties and antioxidant activity. Diarylmethanones were synthesized and their bromination was carried out. During bromination, some compounds gave new bromophenols via regioselective O-demethylation. Demethylation of brominated diarylmethanones was also performed with BBr3 to give novel bromophenols. In addition, we examines the antioxidant capacity of novel bromophenol derivatives using several in vitro bioanalytical methodologies such as 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS⋅+) and 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) radical scavenging activity, Fe3+ and Cu2+ reducing activities and ferrous (Fe2+) ions chelating activities. Also, novel bromophenols and methoxylated bromophenols derivatives were tested against acetylcholinesterase and α-glycosidase, which associated with some metabolic diseases. The novel bromophenols showed Ki values in range of 8.94 ± 0.73–59.45 ± 14.97 nM against AChE and 4.31 ± 1.93–44.14 ± 2.19 nM against α-glycosidase.  相似文献   

18.
One of the main challenges for nowadays medicine is drugs selectivity. In COX-1 and COX-2, the active sites are composed of the same group of amino acids with the exception of the only one residue in position 523, in COX-1 is an isoleucine, while in COX-2 is a valine. Here, we presented a series of isothiazolopyridine/benzisothiazole derivatives substituted differently into an isothiazole ring, which were synthesized and investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. All the tested compounds inhibited the activity of COX-1, the effect on COX-2 activity was differential. The mode of binding was characterized by a molecular docking study. Comparing biological activity of the investigated compounds, it was observed that compounds sharing the most similar position to flurbiprofen and meloxicam, representing the two main enzyme subdomains, achieved higher biological activity than others. It is directly related to the fit to the enzyme’s active site, which prevents too early dissociation of the compounds.  相似文献   

19.
The one pot reactions carried among salicylaldehyde 1, ortho-aminophenols 2a-2g, and di-phenyl-tin(IV) oxide 3 led to seven di-phenyl-tin(IV) compounds 4a-4g in good yields (97-83%). All compounds were analyzed by IR, 1H, 13C, 119Sn NMR spectroscopy, mass spectrometry and elemental analyses; furthermore, in the case of compounds 4b, 4c, 4e and 4g by X-ray diffraction. Compounds 4a-4g were tested in vitro against six human tumor cell lines U251, PC-3, K-562, HCT-15, MCF-7 and SKLU-1 to assess their in vitro antitumor activity. The results suggest biological specificity towards U251, MCF-7 and SKLU-1 cells at doses below 2.5 microM, which are lower than cis-platin IC50's in the three cell lines. Since the inhibitory concentration values for the series were alike to Ph(2)SnCl(2) is feasible that only the Ph(2)Sn moiety is responsible for those activities, further experiments are under research. Besides, 4a-4g were tested for their antioxidant efficiency in rat brain homogenate showing that 4g is more active (IC50=3.01 microM) than the flavone quercetin (natural antioxidant, IC50=4.11 microM) on inhibition of thiobarbituric acid reactive substances (TBARS). The TBARS activity (IC50) correlates with the ortho-aminophenol substitutions and a linear combination among sigma Hammett, one bond tin coupling constants and tin chemical shifts against the measured IC(50-TBARS) was found. This correlation gave basis that the implied molecular variables can become trackers for the calculation of TBARS inhibitory concentrations in similar systems. Moreover, there seemed to be an inverse structure-response behavior among activities, since the 4g derivative is the less active compound for cytotoxic assays meanwhile it is the best in antioxidant tests.  相似文献   

20.
A novel series of fatty acid synthase (FAS) inhibitors with D-(−)-pantolactone moiety and potential utility for the treatment of obesity were designed, synthesized and characterized, in which the structure of compound 3k was further confirmed by single X-ray diffraction. The mouse FAS inhibitory activity of synthesized compounds was evaluated. Major synthesized compounds (except 3g, 3i, 3k, 3l, and 3n) exhibited moderate FAS inhibitory properties with IC50 values in the range of 13.68 ± 1.52–33.19 ± 1.39 μM, reference inhibitor C75 has IC50 value of 13.86 ± 2.79 μM. Eight compounds (3c, 3d, 3e, 3f, 3j, 3m, 3q and 3r) also displayed inhibitory effect on lipid accumulation in human HepG2 cells. Additionally, the molecular docking study revealed that compound 3m having good inhibition activity against FAS and lipid accumulation also showed promising binding affinities with hFAS, while its binding model with hFAS (PDB ID: 4PIV) was different from that of reference compound C75.  相似文献   

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