A Comprehensive Review of Structures, Structure-activity Relationships, Extractions, and Bioactivities of Flavonoids from Citrus medica.

BACKGROUND: Citrus medica is a kind of medicinal and edible plant. It not only contains rich nutrients but also has a variety of therapeutic functions, including relieving pain, harmonizing the stomach, removing dampness, reducing phlegm, cleaning the liver, and relieving qi in traditional Chinese diagnosis. METHODS: The references of C. medica were mainly collected from the online database, such as PubMed, SciFinder, Web of Science, Google Scholar, Elsevier, Willy, SpringLink, and CNKI. The other related references were sorted by consulting books and documents. RESULTS: This review summarized and analyzed the different types of flavonoids of C. medica, including flavone-O-glycosides, flavone-C-glycosides, dihydroflavone-O-glycosides, flavonol aglycones, flavonoid aglycones, dihydroflavonoid aglycones, and bioflavonoids. The extraction methods of flavonoids were summarized in this review. Meanwhile, the multiple bioactivities of these flavonoids, including anti-atherosclerotic, hypolipidemic, anti-oxidant, hypoglycemic, and other activities. Their structure-activity relationships were reviewed and discussed in this paper. CONCLUSIONS: This review summarized the different extraction methods of diverse flavonoids with multiple bioactivities of C. medica, and their structure-activity relationships were discussed in this paper. This review may provide a valuable reference for researching and exploiting C. medica.

Ethnopharmacology, Phytochemistry, and Pharmacology of Pyrethrum tatsienense (Bureau & Franch.) Ling ex C. Shih: A Comprehensive Review.

BACKGROUND: Pyrethrum tatsienense (Bureau & Franch.) Ling ex C. Shih (PTLCS) belongs to the family Compositae, which is a perennial medicinal plant mainly distributed in the Qinghai-Tibet Plateau of China. This review provides a comprehensive summary of the ethnopharmacology, phytochemistry, and pharmacology of PTLCS. This review offers valuable references and guidance for researching PTLCS in depth. METHODS: The related references of PTLCS were retrieved from an online database, such as Web of Science, Google Scholar, SciFinder, PubMed, SpringLink, Elsevier, Willy, CNKI, and so on. RESULTS: PTLCS is widely reported for treating headaches, head injuries, traumatic injuries, anabrosis, impetigo, hepatitis, and other diseases in the medical field. Phytochemical research revealed that this plant contained flavonoid aglycones, flavonoid glycosides, xanthones, triterpenoids, coumarins, polyacetylenes, volatile oils, and other compounds. Meanwhile, PTLCS exhibited extensive pharmacological activities including anti-cardiac ischemia, anti-hypoxia, hepatoprotective, anti- inflammatory and analgesic, and antioxidant activities. CONCLUSIONS: PTLCS is widely used as a Tibetan medicine, which has a variety of chemicals with diverse bioactivities. Therefore, further studies are necessary to perform on the PTLCS to assay biological activities, discover their bioactive constituents, and reveal pharmacological mechanisms. This review may supply an important theoretical basis and valuable reference for in-depth research and exploitations of PTLCS.

Ethnopharmacology, Phytochemistry, and Pharmacology of Highland Barley Monascus purpureus Went: A Comprehensive Review.

BACKGROUND: Highland barley Monascus purpureus Went, a traditional Tibetan medicine with food functions, which is fermented by Monascus purpureus with highland barley as substrate. It possesses various medical functions of promoting blood circulation and removing blood stasis, invigorating spleen and promoting digestion in folk of the Qinghai-Tibet Plateau in China. This review provides a comprehensive overview of ethnopharmacology, phytochemistry, and pharmacology of highland barley Monascus purpureus Went. METHODS: The references of highland barley Monascus purpureus Went were retrieved from the online database, such as Web of Science, Google Scholar, SciFinder, PubMed, SpringLink, Elsevier, Willy, CNKI, and so on. RESULTS: Phytochemical research revealed that highland barley Monascus purpureus Went contained multiple chemical components, including Monascus pigments, monacolins, lactones, and other compounds. The reported pharmacological activities of highland barley Monascus purpureus Went included hypolipidemic, anti-nonalcoholic fatty liver disease, and hepatoprotective activities. CONCLUSION: In a word, botany, ethnopharmacology, phytochemistry and pharmacology of highland barley Monascus purpureus Went were reviewed comprehensively in this paper. In the future, highland barley Monascus purpureus Went needs further study, such as paying more attention to quality control and utilization of medicine. Therefore, this review may provide a theoretical basis and valuable data for future studies and exploitations on highland barley Monascus purpureus Went.

Effect of carbonyl inhibitors and their H2O2 detoxification on lactic acid fermentation.

Biomass degradation compounds significantly inhibit biochemical conversion of biomass prehydrolysates to biofuels and chemicals, such as lactic acid. To characterize the structure-activity relationship of carbonyl inhibition on lactic acid fermentation, we examined effects of eight carbonyl compounds (furfural, 5-hydroxymethyl furfural, vanillin, syringaldehyde, 4-hydroxybenzaldehyde, phthalaldehyde, benzoic acid, and pyrogallol aldehyde) and creosol on lactic acid production by Lactobacillus delbrueckii. Pyrogallol aldehyde reduced the cell growth rate by 35 % at 1.0 mM and inhibited lactic acid production completely at 2.0 mM. By correlating the molecular descriptors to the inhibition constants in lactic acid fermentation, we found a good relationship between the hydrophobicity (Log P) of aldehydes and their inhibition constants in fermentation. The inhibitory effect of carbonyl inhibitors appeared to correlate with their thiol reactivity as well. In addition, we found that H2O2 detoxified pyrogallol aldehyde and phthalaldehyde inhibitory activity. H2O2 detoxification was applied to real biomass prehydrolysates in lactic acid fermentation.

[Study on chemical constituents of triterpenoids from Potentilla discolor].

OBJECTIVE: To study the triterpenoids constituents in Potentilla discolor. METHODS: The compounds were isolated by silica gel chromatography, macroporous resins and polyamide column chromatography from the 70% ethanol extract, and their structures were identified by spectral analysis. RESULTS: Six compounds were obtained and their structures were identified as 3-O-beta-D-glucopyranosyl-(1 --> 2) -beta-D-xylopyranosyl-19a-hydroxyurs-12-en-28-acid (1), 2alpha, 3/beta, 19alpha-trihydroxyurs-12-en-28-acid (2), 3beta, 19alpha-trihydroxyurs-12-en-24, 28-acid (3), 2alpha, 3beta-dihydroxyolean-12-en-28-acid (4), 2alpha, 3alpha, 19alpha-trihydroxyurs-12-en-28-acid (5), beta-sitosterol (6). CONCLUSION: Compounds 1 and 3 are obtained from this plant for the fisrt time.

[Preparation technology of Zhangyanming dispersible tablet and determination of puerarin by HPLC].

OBJECTIVE: To study the extraction and pharmceutics technology of Zhangyanming dispersible tablet and establish the method for determining the content of puerarin by HPLC. METHODS: Using total extracted puerarin and disintegrating time as evaluation indexes and the conditions for determination were as follows: Hypersil BDS C18 column (5 microm, 4.6 mm x 200 mm), Methanol-H2O (25:75) as the mobile phase, the detection wavelength at 250 nm, the column temperature at 30 degrees C, and 1.0 mL/min as the mobile phase speed. RESULTS: The calibration curve was linear at the range of 0.1699 to 1.3594 microg for the puerarin content and the linear equation was y = 3.054 x 10(6)x - 24019 (r = 0.9998). The average recovery ratio was 100.03%, and the relative standard deviation was 1.79%. CONCLUSIONS: The new preparation technology is reasonable and HPLC can be used to determine the content of puerarin in Zhangyanming dispersible tablet because the operation was convenient, fast, easy to repeat, and the analysis results were accurate and especial.

[Selection of acetate-tolerant mutants from Escherichia coli DH5alpha and the metabolic properties of mutant DA19].

Esherichia coli DH5alpha is one of the widely used host strains in genetic engineering. However, foreign gene expression level in this strain is seriously inhibited due to its great sensitivity to the accumulated metabolite, acetate. This study aimed at improving the tolerance of this strain against acetate. Cells of E. coli DH5alpha were irradiated with 60Co, and subsequently continuous culture of the irradiated cells was conducted with gradual increase in the dilution rate and the selective pressure, acetate concentration in the medium. The mutants were picked up on MA plates which contained 5g/L sodium acetate. 5 strains with great improvement in acetate tolerance were obtained, among which DA19 was the best. In cultivation of DA19 in complex media YPS and YPS2G, the cell density, maximum specific growth rate and acetate produced were respectively 1.17 and 1.05, 1.08 and 1.27, and 0.06 and 0.59 times of those of DH5alpha. In a chemically defined medium, the cell density of DA19 was 3.4-fold of that of DH5alpha. The cell density of DA19 in a medium containing 10g/L sodium acetate was comparable to that of DH5alpha in the same medium without the addition of acetate.