Extraction of Herba Lycopi Polysaccharide and Study of Its Antioxidant Activity by Cellulase Method

[Objectives] To optimize the extraction process of Herba Lycopi polysaccharide by cellulase,and study its antioxidant activity.[Methods]The single factor test and orthogonal test were conducted to study the effect of p H,enzyme dosage,enzymolysis temperature and extraction time on the extraction of Herba Lycopi polysaccharide. And the test was done about its scavenging effect on DPPH radicals and superoxide anions,and the antioxidant activity was evaluated. [Results] The optimum extraction process by cellulase method was as follows: p H value of 7; enzyme dosage of 4 ml; enzymolysis temperature of 40 ℃; extraction time of 2. 5 h. The average extraction rate of Herba Lycopi polysaccharide was 10. 70%,and RSD was 0. 17%. The antioxidant activity test showed that Herba Lycopi polysaccharide had a significant scavenging effect on radicals. [Conclusions] Herba Lycopi polysaccharides had strong antioxidant activity,and could provide a scientific basis for the development and utilization of Herba Lycopi medicinal resources.

Optimization of Extraction Process and Determination of Antioxidant Activity of Myrica ruba Leaf Pigment by Orthogonal Design

[Objectives] To determine the optimum conditions and antioxidant activity of Myrica ruba leaf pigment,and provide reference for further development and use of Myrica ruba leaves. [Methods]Pigment of Myrica ruba leaves was extracted by ethanol extraction method. Absorbance was measured at wavelength of 300 nm. Effects of ethanol volume fraction,solid-to-liquid ratio,temperature,and extraction time were studied. L_9( 3~3) orthogonal experiment was carried out to optimize the extraction process,and DPPH scavenging ability was measured.[Results]The optimum extraction process of Myrica ruba leaf pigment was as follows: the ethanol volume fraction was 50%; the solid-to-liquid ratio was 1: 60( w/v),extraction temperature 70℃; extraction time was 60 min; after the concentration of purified Myrica ruba leaf pigment reached 0. 4455 mg/mL,the DPPH scavenging ability was basically the same as the same concentration Vc.[Conclusions] The experiment indicates that the optimized extraction process has a high yield rate,and Myrica ruba leaf pigment has high anti-oxidant activity.

Advances in Researches of Extraction Processes of Total Saponins of Pnanx Notoginseng

Traditional extraction methods of total saponins of Panax notoginseng include cold soaking method,water decoction method,alcohol reflux method,percolation method,macroporous resin adsorption method,and accelerated solvent extraction( ASE) method. Modern extraction methods include ultrasonic extraction,microwave assisted extraction,supercritical CO_2 extraction,microbial fermentation assisted extraction,neural network model optimized extraction method,and multi-stage countercurrent extraction method. This paper discussed principles of these methods and compared their advantages and disadvantages.

Comparison of Extraction Methods for Total Alkaloids from Abrus Cantoniensis Hance

[Objectives] To compare different extraction methods for total alkaloids from Abrus Cantoniensis Hance taking chloroform as solvent. [Methods] The ethanol extraction method,ultrasonic extraction method,acid water extraction method,and Soxhlet extraction method were used to extract total alkaloids,and the total alkaloids of Abrus Cantoniensis Hance were measured at 238 nm wavelength. [Results] The extraction rate of ethanol extraction method was 14. 76 mg/100 g; the extraction rate of ultrasonic extraction method was 56. 85 mg/100 g; the extraction rate of acid water extraction method was 56. 63 mg/100 g; the extraction rate of Soxhlet extraction method was 58. 19 mg/100 g.[Conclusions]Results indicate that Soxhlet extraction method can obtain the highest extraction rate.

Single-stranded RNA as primers of terminal deoxynucleotidyl transferase for template-independent DNA polymerization

Terminal deoxynucleotidyl transferase(Td T) has been characterized as template-independent polymerase using single-stranded DNA(ss DNA) as primers to generate random oligonucleotides. However, the extension performance of Td T to single-stranded RNA(ss RNA) is vague. By systematically comparing and contrasting the performance of Td T-catalyzed ss DNA and ss RNA extension, it is indicated that the catalytic efficiency of ss RNA as primers was about 3 times lower than ss DNA as primers. Collectively, it is believed that understanding the catalytic performance of Td T will help to design the strategy to synthesize chimeric DNA on 3-OH of ss RNA, which becomes invaluable.