Organic and Medicinal Chemistry Letters最新文献

Background: Nanotechnology is now regarded as a distinct field of research in modern science and technology with multifaceted areas including biomedical applications. Among the various approaches currently available for the generation of metallic nanoparticles, biogenic synthesis is of increasing demand for the purpose of green nanotechnology. Among various natural sources, plant materials are the most readily available template-directing matrix offering cost-effectiveness, eco-friendliness, and easy handling. Moreover, the inherent pharmacological potentials of these medicinal plant extracts offer added biomedical implementations of the synthesized metal nanoparticles.

Results: A robust practical method for eco-friendly synthesis of silver nanoparticles using aqueous leaf extract of Ocimum sanctum (Tulsi) as both reducing and capping agent, under the influence of direct sunlight has been developed without applying any other chemical additives. The nanoparticles were characterized with the help of UV-visible spectrophotometer and transmission electron microscopy (TEM). The prepared silver nanoparticles exhibited considerable antibacterial activity. The effects were more pronounced on non-endospore-forming Gram-positive bacteria viz., Staphylococcus aureus, Staphylococcus epidermidis, and Listeria monocytogenes than endospore-forming species Bacillus subtilis. The nanoparticles also showed prominent activity on Gram-negative human pathogenic Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, and plant pathogenic Pantoea ananatis. A bactericidal mode of action was observed for both Gram-positive and Gram-negative bacteria by the nanoparticles.

Conclusions: We have developed a very simple, efficient, and practical method for the synthesis of silver nanoparticles using aqueous leaf extract of O. sanctum under the influence of direct sunlight. The biosynthesis of silver nanoparticles making use of such a traditionally important medicinal plant without applying any other chemical additives, thus offers a cost-effective and environmentally benign route for their large-scale commercial production. The nanoparticles dispersed in the mother solution showed promising antibacterial efficacy. Graphical AbstractSunlight-induced rapid and efficient biogenic synthesis of silver nanoparticles using aqueous leaf extract of Ocimum sanctum Linn. with enhanced antibacterial activity.

Background: The aim of this study was to evaluate the effects of nitroxin biofertilizer and chemical fertilizer on the growth, yield, and essential oil composition of dill. The experiment was conducted under field condition in randomized complete block design with three replications and two factors.

Results: The first factor was the concentrations of nitroxin biofertilizer (0%, 50%, and 100%) of the recommended amount (1 l of biological fertilizer for 30 kg of seed). The second factor was the following chemical fertilizer treatments: no fertilizer (control) and 50 and 100 kg ha(-1) urea along with 300 kg ha(-1) ammonium phosphate. Different characteristics such as plant height, number of umbel per plant, number of umbellet per umbel, number of grain per umbellet, 1,000 seed weight, grain yield, biological yield, and oil percentage were recorded. According to the results, the highest height, biological yield, and grain yield components (except harvest index) were obtained on biological fertilizer. The results showed the highest essential oil content detected in biological fertilizer and chemical fertilizer. Identification of essential oil composition showed that the content of carvone increased with the application of biofertilizers and chemical fertilizers. The results indicated that the application of biofertilizers enhanced yield and other plant criteria in this plant.

Conclusions: Generally, it seems that the use of biofertilizers or combinations of biofertilizer and chemical fertilizer could improve dill performance in addition to reduction of environmental pollution.

Background: A series of 6-(substituted aldehyde)-3,4-dihydro-1-(tetrahydro-3,4-dihydroxy-5-(hydroxymethyl) furan-2-yl)-4-phenylpyrimidine-2(1H)-one derivative (6A-6P) was synthesized from the 6-(substituted aldehyde)-4-phenylpyrimidine-2(1H)-one derivative (5A-5P) through following reaction mechanisms Claisen-Schmidt, Cyclization, and Satos fusion. The structures of the synthesized compounds were elucidated by I.R.,(1)H-NMR, elemental analysis, and mass spectroscopic techniques.

Result: The synthesized compounds were screened for in vitro antifungal activity at 25, 50, 100, and 200 μg/ml concentrations. Among them, compounds 6P, 6D, and 6M exhibited significant antifungal activity that was carried out by cup plate method against fungal strain which was collected from IMTECH Chandigarh, India, against standard drug fluconazole. Compounds have been further evaluated by measuring zone of inhibition and percent inhibition. The synthesized compounds were screened for in vitro antioxidant activity using the DPPH assay, based on the AAI and antioxidant activity unit (AAU), using a combination relation between DPPH concentration and absorbance. The antioxidant strength of compounds was compared against ascorbic acid. Among them, compounds 6K, 6F, 6E, 6G, 6H, and 6M exhibited significant antioxidant activity and 6J have less active compound. The data of these synthesized compounds were submitted to the National Institute of Health, USA, under the drug discovery program of National Cancer Institute (NCI) and screened for anticancer activity at a single high dose (10(-5) M) in full NCI 60 cell lines. The selected compounds have shown potent significant anticancer activity in the NCI 60 cell line screening.

Conclusion: A new series of pyrimidine analogues that contain furanose moiety were synthesized by Satos fusion and characterized. The synthesized compounds screened for their in vitro antioxidant, antifungal activity, as well as anticancer activity given by the derivative which has chloro, methoxy, nitro, and chloro substitution having furanose contain pyrimidine derivative that showed the most potent activity.

Background: The aim of this study was to evaluate the effect of nano silver and silver nitrate on yield of seed in basil plant. The study was carried out in a randomized block design with three replications.

Results: Four levels of either silver nitrate (0, 100, 200 and 300 ppm) or nano silver (0, 20, 40, and 60 ppm) were sprayed on basil plant at seed growth stage. The results showed that there was no significant difference between 100 ppm of silver nitrate and 60 ppm concentration of nano silver on the shoot silver concentration. However, increasing the concentration of silver nitrate from 100 to 300 ppm caused a decrease in seed yield. In contrast, a raise in the concentration of nano silver from 20 to 60 ppm has led to an improvement in the seed yield. Additionally, the lowest amount of seed yield was found with control plants.

Conclusions: Finally, with increasing level of silver nitrate, the polyphenol compound content was raised but the enhancing level of nano silver resulting in the reduction of these components. In conclusion, nano silver can be used instead of other compounds of silver.