Variation of loganin content in Cornus officinalis fruits at different extraction conditions and maturation stages.

Efficient preparation of loganin from Cornus officinalis fruits was investigated. First, effect of extraction conditions on loganin yield was measured. The loganin content in C. officinalis extract was greatly affected by ethanol concentration and extraction time whereas extraction temperature exerted relatively little effect. Response surface methodology with Box-Behnken design suggested optimized extraction condition for maximum loganin yield as ethanol concentration, 32.0%; temperature 46.2 °C and extraction time, 46.7 min, which yielded 10.4 µg loganin/mg dried fruit. Next, the effect of maturation stage of C. officinalis fruits on loganin content was investigated. The loganin content in the extract of C. officinalis fruits was decreased as the maturation process. The loganin content in the unripe fruits was 18.0 µg/mg extract whereas reduced to 13.3 µg/mg extract for ripe fruits. Taken together, our present study suggested the importance of extraction condition and maturation stages for efficient preparation of loganin from C. officinalis fruits.

Inositol Derivatives and Phenolic Compounds from the Roots of Taraxacum coreanum.

In this study, the characterization of chemical constituents and biological activity of the roots of Taraxacum coreanum (Asteraceae) was attempted. Phytochemical investigation of the roots of T. coreanum led to the isolation of two new inositol derivatives, taraxinositols A (1) and B (2), and a new phenolic compound, taraxinol (16), together with twenty known compounds including four inositol derivatives, neo-inositol-1,4-bis (4-hydroxybenzeneacetate) (3), chiro-inositol-1,5-bis(4- hydroxybenzeneacetate) (4), chiro-inositol-2,3-bis (4-hydroxybenzeneacetate) (5) and chiro-inositol- 1,2,3-tris (4-hydroxybenzeneacetate) (6), nine phenolic compounds: p-hydroxybenzaldehyde (7), vanillin (8), syringaldehyde (9), vanillic acid (10), 4-methoxyphenylacetic acid (11), 4-hydroxy- phenylacetic acid methyl ester (12), optivanin (13), isoferulic acid (14) and dihydroconiferyl alcohol (15), four coumarins: nodakenetin (17), decursinol (18), prangol (19) and isobyakangelicin (20), and three lignans: syringaresinol-4'-O-ß-d-glucoside (21), syringaresinol (22), and pinoresinol (23). The structures of isolated compounds were determined on the basis of spectroscopic analysis. Among the isolated compounds, vanillic acid, isoferulic acid and syringaresinol showed radical scavenging activity with IC50 values ranging from 30.4 to 75.2 µM.

Effect of Korean Red Ginseng extraction conditions on antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content: optimization using response surface methodology.

BACKGROUND: Extraction conditions greatly affect composition, as well as biological activity. Therefore, optimization is essential for maximum efficacy. METHODS: Korean Red Ginseng (KRG) was extracted under different conditions and antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content evaluated. Optimized extraction conditions were suggested using response surface methodology for maximum antioxidant activity and extraction yield. RESULTS: Analysis of KRG extraction conditions using response surface methodology showed a good fit of experimental data as demonstrated by regression analysis. Among extraction factors, such as extraction solvent and extraction time and temperature, ethanol concentration greatly affected antioxidant activity, extraction yield, and ginsenoside Rg1 and phenolic content. The optimal conditions for maximum antioxidant activity and extraction yield were an ethanol concentration of 48.8%, an extraction time 73.3 min, and an extraction temperature of 90°C. The antioxidant activity and extraction yield under optimal conditions were 43.7% and 23.2% of dried KRG, respectively. CONCLUSION: Ethanol concentration is an important extraction factor for KRG antioxidant activity and extraction yield. Optimized extraction conditions provide useful economic advantages in KRG development for functional products.

Characterization of Melanogenesis Inhibitory Constituents of Morus alba Leaves and Optimization of Extraction Conditions Using Response Surface Methodology.

Melanin is a natural pigment that plays an important role in the protection of skin, however, hyperpigmentation cause by excessive levels of melatonin is associated with several problems. Therefore, melanogenesis inhibitory natural products have been developed by the cosmetic industry as skin medications. The leaves of Morus alba (Moraceae) have been reported to inhibit melanogenesis, therefore, characterization of the melanogenesis inhibitory constituents of M. alba leaves was attempted in this study. Twenty compounds including eight benzofurans, 10 flavonoids, one stilbenoid and one chalcone were isolated from M. alba leaves and these phenolic constituents were shown to significantly inhibit tyrosinase activity and melanin content in B6F10 melanoma cells. To maximize the melanogenesis inhibitory activity and active phenolic contents, optimized M. alba leave extraction conditions were predicted using response surface methodology as a methanol concentration of 85.2%; an extraction temperature of 53.2 °C and an extraction time of 2 h. The tyrosinase inhibition and total phenolic content under optimal conditions were found to be 74.8% inhibition and 24.8 µg GAE/mg extract, which were well-matched with the predicted values of 75.0% inhibition and 23.8 µg GAE/mg extract. These results shall provide useful information about melanogenesis inhibitory constituents and optimized extracts from M. alba leaves as cosmetic therapeutics to reduce skin hyperpigmentation.

Pancreatic lipase inhibitory constituents from Morus alba leaves and optimization for extraction conditions.

The leaves of Morus alba (Moraceae) have been traditionally used for the treatment of metabolic diseases including diabetes and hyperlipidemia. Thus, inhibitory effect of M. alba leaves on pancreatic lipase and their active constituents were investigated in this study. Twenty phenolic compounds including ten flavonoids, eight benzofurans, one stilbene and one chalcones were isolated from the leaves of M. alba. Among the isolated compounds, morachalcone A (20) exerted strong pancreatic lipase inhibition with IC50 value of 6.2 µM. Other phenolic compounds containing a prenyl group showed moderate pancreatic lipase inhibition with IC50 value of <50 µM. Next, extraction conditions with maximum pancreatic lipase inhibition and phenolic content were optimized using response surface methodology with three-level-three-factor Box-Behnken design. Our results suggested the optimized extraction condition for maximum pancreatic lipase inhibition and phenolic content as ethanol concentration of 74.9%; temperature 57.4 °C and sample/solvent ratio, 1/10. The pancreatic lipase inhibition and total phenolic content under optimized condition were found to be 58.5% and 26.2 µg GAE (gallic acid equivalent)/mg extract, respectively, which were well matched with the predicted value.