The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial an...The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial and antioxidant properties of the extracts was also conducted. 32 compounds of P. cuspidatum and 23 compounds of Streptomyces sp. A0916 were isolated and identified by GC/MS. Antimicrobial activities of the extracts were evaluated using eight microbial strains(3 Gram-positive bacteria, 3 Gram-negative bacteria, and 2 fungi). The Streptomyces sp. A0916 extracts showed a wide range of antimicrobial activities and presented greater antimicrobial effectiveness than the P. cuspidatum extracts. The minimum inhibitory concentration(MIC) of Streptomyces sp. A0916 extracts against the ampicillin-resistant strain Enterococcus faecium SIIA843 was 32 μg·m L-1. Furthermore, the extracts had greater antimicrobial effect against Gram-positive bacteria than Gram-negative bacteria. Finally, the antioxidant activity of the Streptomyces sp. A0916 extracts was equal to that of the P. cuspidatum extracts. In conclusion, our results suggest that the endophytic actinomycetes of the medicinal plants are an important source of bioactive substances.展开更多
A novel and efficient extraction/hydrolysis method was developed for the recovery of resveratrol and emodin from a well-known traditional chinese medicinal herb, Polygonum cuspidatum. By using a 85% aqueous acetone so...A novel and efficient extraction/hydrolysis method was developed for the recovery of resveratrol and emodin from a well-known traditional chinese medicinal herb, Polygonum cuspidatum. By using a 85% aqueous acetone solution containing 1.0 mol/L HCl as extractant, extraction of resveratrol and emodin from P. cuspidatum and conversion of resveratrol-3-O-β-glucoside and emodin-8-O-β-D-glucoside into the products could be achieved in one step. The effects of several key parameters including concentration of HCl and acetone, temperature, ratio of solvent to material, extraction duration and extraction times on the process efficiency was systematically investigated. The results showed that the optimal conditions for maximizing the recovery yield were 85% acetone containing 1.0 mol/L HCl as extractant, temperature 70 ℃, ratio of liquid to solid 50 mL /g and extraction duration 30 min. This one-pot extraction/hydrolysis process increased the yield of resveratrol and emodin to 524% and 302%, respectively, compared to a raw sample without hydrolysis. Compared with conventional method, the developed process not only achieved high yield of resveratrol and emodin, but simplified the procedures and reduced time. The results demonstrated that the simultaneous extraction/hydrolysis process is simple and efficient which could act as a useful approach for enhanced recovery of resveratrol and emodin from P. cuspidatum.展开更多
目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制...目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制备的天然低共熔溶剂(natural deep eutectic solvents,NADESs)与传统低共熔溶剂(traditional deep eutectic solvents,DESs)对制何首乌中大黄素的提取情况,并通过试验验证该模型预测结果的准确性,进一步解释提取机理。结果:经COSMO模型预测,大黄素与1,3-丙二醇-乳酸(1∶3)组成的NADES间的相互作用能为-762.8972 kJ/mol,显著高于大黄素与甲醇和水间的相互作用能。相互作用能越大,提取效率越高。最终预测大黄素提取效率由高到低依次为1,3-丙二醇-乳酸(1∶3)、甲醇、水。经试验进一步验证,NADES对大黄素的提取率为1.1266 mg/g,提取效率是水的16.07倍,甲醇的1.19倍,整体趋势与COSMO模型预测结果一致。结论:COSMO模型不仅可以准确预测大黄素在不同溶剂中的溶解规律,还可以从微观角度解释提取机理,可为各类天然产物高效提取溶剂的选择提供一定借鉴。展开更多
基金supported by Department of Science and Technology of Sichuan Province,China(No.2014 JY0199)
文摘The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial and antioxidant properties of the extracts was also conducted. 32 compounds of P. cuspidatum and 23 compounds of Streptomyces sp. A0916 were isolated and identified by GC/MS. Antimicrobial activities of the extracts were evaluated using eight microbial strains(3 Gram-positive bacteria, 3 Gram-negative bacteria, and 2 fungi). The Streptomyces sp. A0916 extracts showed a wide range of antimicrobial activities and presented greater antimicrobial effectiveness than the P. cuspidatum extracts. The minimum inhibitory concentration(MIC) of Streptomyces sp. A0916 extracts against the ampicillin-resistant strain Enterococcus faecium SIIA843 was 32 μg·m L-1. Furthermore, the extracts had greater antimicrobial effect against Gram-positive bacteria than Gram-negative bacteria. Finally, the antioxidant activity of the Streptomyces sp. A0916 extracts was equal to that of the P. cuspidatum extracts. In conclusion, our results suggest that the endophytic actinomycetes of the medicinal plants are an important source of bioactive substances.
基金Supported by the National Natural Science Foundation of China(No.2113600921506221)
文摘A novel and efficient extraction/hydrolysis method was developed for the recovery of resveratrol and emodin from a well-known traditional chinese medicinal herb, Polygonum cuspidatum. By using a 85% aqueous acetone solution containing 1.0 mol/L HCl as extractant, extraction of resveratrol and emodin from P. cuspidatum and conversion of resveratrol-3-O-β-glucoside and emodin-8-O-β-D-glucoside into the products could be achieved in one step. The effects of several key parameters including concentration of HCl and acetone, temperature, ratio of solvent to material, extraction duration and extraction times on the process efficiency was systematically investigated. The results showed that the optimal conditions for maximizing the recovery yield were 85% acetone containing 1.0 mol/L HCl as extractant, temperature 70 ℃, ratio of liquid to solid 50 mL /g and extraction duration 30 min. This one-pot extraction/hydrolysis process increased the yield of resveratrol and emodin to 524% and 302%, respectively, compared to a raw sample without hydrolysis. Compared with conventional method, the developed process not only achieved high yield of resveratrol and emodin, but simplified the procedures and reduced time. The results demonstrated that the simultaneous extraction/hydrolysis process is simple and efficient which could act as a useful approach for enhanced recovery of resveratrol and emodin from P. cuspidatum.
文摘目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制备的天然低共熔溶剂(natural deep eutectic solvents,NADESs)与传统低共熔溶剂(traditional deep eutectic solvents,DESs)对制何首乌中大黄素的提取情况,并通过试验验证该模型预测结果的准确性,进一步解释提取机理。结果:经COSMO模型预测,大黄素与1,3-丙二醇-乳酸(1∶3)组成的NADES间的相互作用能为-762.8972 kJ/mol,显著高于大黄素与甲醇和水间的相互作用能。相互作用能越大,提取效率越高。最终预测大黄素提取效率由高到低依次为1,3-丙二醇-乳酸(1∶3)、甲醇、水。经试验进一步验证,NADES对大黄素的提取率为1.1266 mg/g,提取效率是水的16.07倍,甲醇的1.19倍,整体趋势与COSMO模型预测结果一致。结论:COSMO模型不仅可以准确预测大黄素在不同溶剂中的溶解规律,还可以从微观角度解释提取机理,可为各类天然产物高效提取溶剂的选择提供一定借鉴。
