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Objective To optimize extraction technology and evaluate the stability of anthocyanins from Duchesnea indica by response surface methodology. Methods Based on single factor experiment, the ethanol concentration, liquid-material ratio, extraction time, and extraction temperature were selected as independent variables, and the anthocyanin extraction ratio was selected as response value. The Box-Behnken design method and response surface methodology were used to optimize the extraction technology. Additionally, the effects of pH, temperature, organic acid, and oxidizer on the stability of anthocyanins were investigated. Results The optimized extraction technology: ethanol concentration was 80%, liquid-material ratio was 10:1, extraction time was 93 min, and extraction temperature was 36 ℃. The ratio of the extraction of anthocyanins with the optimal technology was 1.126%. The stability experiments results showed that the anthocyanins should keep in acid and low temperature conditions. Adding citric acid and gallic acid enhanced its stability, but glycine and H2O2 decreased stability. Conclusion The extraction technology optimized by response surface methodology was scientific, reasonable, and feasible, and it can be applicable for the extraction of anthocyanins from D. indica. Moreover, the condition should be paid attention to in order to maintain the stability of anthocyanins from D. indica.
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AIM To establish an HPLC method for the simuhaneous content determination of five flavonoids in Duchesnea indica (Andr.) Focke at five picking time (April,May,June,July and August).METHODS The analysis of D.indica methanol extract was performed on a 25 ℃ thermostatic Agilent ZORBAX SB-C18 column (250 mm×4.6 mm,5 μm),the mobile phase comprising of acetointrile-0.1％ methanoic acid flowing at 1.0 mL/min in a gradient elution manner,and the detection wavelength was set at 350 nm.RESULTS Rutin,hyperoside,isoquercitrin,celereoin and kaempferol showed good linear relationships within their own ranges (R2 ≥0.998 6),whose average recoveries were 97.1％-101.5％ with the RSDs of 1.37％-2.37％.The contents of five constituents in samples at different picking time exhibited obvious differences,among which lutin and hyperoside contents were the highest in June,isoquercitrin content was the highest in July,and celereoin and kaempferol contents were the highest in August.CONCLUSION The suitable picking time of D.indica is June and July.
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OBJECTIVE:To study the genetic diversity of germplasm resources of Duchesnea indica from Hunan. METHODS:The random amplified polymorphic DNA(RAPD)reaction system of germplasm resources was established and RAPD-PCR was ad-opted to detect the expressions of 24 groups of D. indica from Hunan(including 21 wild and 3 cultivated varietos in different geo-graphical distribution). Agarose gel electrophoresis was used to analyze the results and calculate allele number (Na),effective al-lele number (Ne) the polymorphism points percentage (PPB),Nei’s gene diversity index (H) and Shannon’s information index (I). RESULTS:Totally 14 polymorphic primers were screened and 90 electrophoresis bands were amplified,including 81 polymor-phic bands with Na of 1.900 0,Ne of 1.540 1,PPB of 90.0%,H of 0.312 8 and I of 0.467 5. CONCLUSIONS:The genetic diver-sity of D. indica from Hunan is rich,and there were differences in genetic background between the cultivated species and wild spe-cies;clustering results show significant correlation with geographic distribution.
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ThevolatilecompositionsofDuchesneaindicawerestudiedbyheadspacesolid-phase microextraction ( HS-SPME ) , soxhlet extraction ( SE ) , ultrasonic assistant extraction ( UAE ) and steam distillation ( SD) coupled with gas chromatography-mass spectrometry ( GC-MS) . The experimental parameters of HS-SPME, including fiber type, extraction temperature, extraction time and desorption time were investigated. 47, 32, 16 and 16 compounds were identified by HS-SPME, SD, SE and UAE extracting methods, respectively. 66 compounds were obtained in total, among which 47 compounds were first reported in Duchesnea indica. The experimental results showed that terpenoids were the most abundant compositions in HS-SPME and SD, but acids accounted for 61. 44% and 69. 54% of the total content obtained by SE and UAE.
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Objective: To investigate the chemical constituents in the EtOAc fraction of the EtOH extract of Duchesnea indica Andr. Focke. Methods: Extraction was done with 95% EtOH. EtOAc fraction of the EtOH extract was isolated and purified by column chromatography using silica gel,RP-C18,Sephadex LH-20 and HPLC. The structures of the compounds were identified by their physico-chemical properties and spectral analysis. Results: Thirteen compounds were obtained from the EtOAc fraction of Duchesnea indica Andr. Focke and they were identified as euscaphic acid(1),arjunic acid(2),p-hydroxy cinnamic acid (3),apigenin(4),kaempferol(5),2α-hydroxy ursolic acid(6),2α-hydroxy oleanolic acid(7),tomentic acid(8),kaii-ichigeside F1 (9), potengriffioside A (10), rosamultin (11), kaempferol-3-O-β-D-glucoside (12), and isoquercitrin (13). Conclusion: The compounds 2-5,10, and 12 have been isolated from the genus of Duchesnea for the first time.