Enzyme-assisted ultrasonic extraction of total flavonoids and extraction polysaccharides in residue from Abelmoschus manihot (L).

Abelmoschus manihot (L) is a traditional chinese herb and the present study focused on its comprehensive development and utilization. Enzyme-assisted ultrasonic extraction (EUAE) was investigated for the extraction and qualitative and quantitative analysis of flavonoids from Abelmoschus manihot (L) using a combination of ultra-performance liquid chromatography-photodiode array (UPLC-PDA), polysaccharides was extracted from residues and compared with directly extracted from raw materials. The optimal yield of 3.46±0.012 % (w/w) was obtained when the weight ratio of cellulase to pectinase was 1:1, the enzyme concentration was 3 %, the pH was 6.0, the solvent was a mixture of 70 % ethanol (v/v) and 0.1 mol/L NaH2PO4 buffer solution, the ultrasonic power was 500 W, the extraction time was 40 min, and the temperature of the extraction was 50 °C. The individual concentrations of interested flavonoids (rutin, neochlorogenic acid, nochlorogenic acid, lsoquercitrin, quercitrin, gossypin, quercetin) were effectively increased with the using of EUAE, compared with ultrasonic extraction (UE) method. Polysaccharides were extracted from each residue, respectively, the Polysaccharides yield in residue from EUAE was higher than that from UE, and closed to the yield from direct extraction in raw materials. The above results shown that the experimental process had the potential to be environmentall, friendly, straightforward and efficient.

Metabolomics Characterization of Two Apocynaceae Plants, Catharanthus roseus and Vinca minor, Using GC-MS and LC-MS Methods in Combination.

Catharanthus roseus (C. roseus) and Vinca minor (V. minor) are two common important medical plants belonging to the family Apocynaceae. In this study, we used non-targeted GC-MS and targeted LC-MS metabolomics to dissect the metabolic profile of two plants with comparable phenotypic and metabolic differences. A total of 58 significantly different metabolites were present in different quantities according to PCA and PLS-DA score plots of the GC-MS analysis. The 58 identified compounds comprised 16 sugars, eight amino acids, nine alcohols and 18 organic acids. We subjected these metabolites into KEGG pathway enrichment analysis and highlighted 27 metabolic pathways, concentrated on the TCA cycle, glycometabolism, oligosaccharides, and polyol and lipid transporter (RFOS). Among the primary metabolites, trehalose, raffinose, digalacturonic acid and gallic acid were revealed to be the most significant marker compounds between the two plants, presumably contributing to species-specific phenotypic and metabolic discrepancy. The profiling of nine typical alkaloids in both plants using LC-MS method highlighted higher levels of crucial terpenoid indole alkaloid (TIA) intermediates of loganin, serpentine, and tabersonine in V. minor than in C. roseus. The possible underlying process of the metabolic flux from primary metabolism pathways to TIA synthesis was discussed and proposed. Generally speaking, this work provides a full-scale comparison of primary and secondary metabolites between two medical plants and a metabolic explanation of their TIA accumulation and phenotype differences.

Responses in the morphology, physiology and biochemistry of Taxus chinensis var. mairei grown under supplementary UV-B radiation.

The effects of supplemental UV-B radiation on Taxus chinensis var. mairei were studied. Leaf traits, gas exchange parameters and the concentrations of photosynthetic pigments, cellular defense system products, secondary metabolites and ultrastructure were determined. UV-B radiation significantly decreased leaf area (p<0.05). Leaf number, secondary branch number, leaf weight per plant and leaf moisture all increased dramatically (p<0.05). Neither the leaf weight nor the specific leaf weight (SLW) exhibited significant differences between ambient and enhanced UV-B radiation. Gas exchange parameters were all dramatically reduced by enhanced UV-B radiation (p<0.05). The contents of chlorophyll and the chlorophyll a/b ratio were not distinctly affected by UV-B radiation, while carotenoids content significantly decreased (p<0.05). Supplemental UV-B treatment induced significant flavonoid accumulation (p<0.05), which was able to protect plant from radiation damage. Meanwhile, the appendage content, abaxial stomatal density, papilla density and particulate matter content in substomatic chambers increased noticeably by supplemental UV-B radiation, whereas the aperture size of single stomata was diminished. The number and area of plastoglobuli were apparently reduced by UV-B radiation, but stroma and grana lamellae were not destroyed. Our results demonstrated that T. chinensis var. mairei can activate several defense mechanisms against oxidative stress injury caused by supplemental UV-B radiation.