ABSTRACT
The attractive purple color of blueberries (Vaccinium spp.) is unstable and susceptible to degradation during food processing and storage. The effects of various factors on the color stability of fresh blueberry juice were investigated. Total soluble solid content, pH, and total anthocyanin content were measured. Heating at 30°C and 60°C for 300 min did not influence the color stability, but heating at 100°C drastically decreased it by 33.0%. Sugars decreased color in a concentration-dependent manner. However, glucose and galactose had significantly protective effects on the color disruption than fructose, maltose, and sucrose. Organic acids lowered the color intensity in the order of citric acid> tartaric acid> malic acid> formic acid> acetic acid during 10 days of storage. Color decreased faster during long-term light exposure than in the dark. The color in the dark was kept by 58.7% after 7 weeks, while 48.9% in the light. Color retention was significantly decreased to 93.5% and 93.8% at 4°C and -20°C, respectively, after 7 weeks, while 95.40% at -75°C. We suggest that blueberry juice color can be protected by keeping the extraction temperature below 60°C with the selective addition of glucose, galactose, or citric acid. For long-term storage, it is recommended to use a light-protected container and a deep freezer at -75°C.
ABSTRACT
Six lignans including two new lignans were obtained as the principal components of the Forsythia koreana flowers via silica gel (SiO2 ), octadecyl SiO2 (ODS) as well as Sephadex LH-20 column chromatography. In addition to two new lignans, named koreanaside A ((7R,8S,7'R,8'S)-7,7'-diepoxy-5'-hydroxy-3,3'-dimethoxylignan 4-O-ß-d-glucopyranoside) and koreanaside B ((7R,8S,7'S,8'R)-7,9'-epoxy-9,5',7'-trihydroxy-3,3'-dimethoxylignan 4-O-ß-d-glucopyranoside), four known lignans were identified to be (+)-phylligenin, (-)-epipinoresinol, pinoresinol, and tinosposide A. The structures and absolute configurations of koreanasides A and B were established by means of analysis of spectroscopic data (NMR, IR, FAB-MS, and CD), whereas the structures of known lignans were identified by comparison their NMR and MS values with those in the reported literature. Their chemical structures including configuration were established by means of analysis of spectroscopic data (NMR, IR, FAB-MS, and CD) but also comparison of their NMR and MS values with those in the reported literature. This is the first article for isolation of six lignans of F. koreana flowers. Koreanasides A and B showed high radical scavenging activity with oxygen radical absorbance capacity (ORAC) values of 0.97 ± 0.01 and 1.02 ± 0.01, respectively. Koreanaside A also prohibited expressing VCAM-1 in MOVAS cells with 80.5% at 25 mg/mL.
Subject(s)
Flowers/chemistry , Forsythia/chemistry , Lignans/pharmacology , Muscle, Smooth, Vascular/drug effects , Vascular Cell Adhesion Molecule-1/antagonists & inhibitors , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Lignans/chemistry , Lignans/isolation & purification , Lipopolysaccharides/antagonists & inhibitors , Lipopolysaccharides/pharmacology , Macrophages/drug effects , Macrophages/metabolism , Mice , Molecular Structure , Muscle, Smooth, Vascular/metabolism , RAW 264.7 Cells , Structure-Activity Relationship , Vascular Cell Adhesion Molecule-1/biosynthesisABSTRACT
Three new chlorinated sesquiterpenes, named lepistatins A-C, were isolated from the culture broth of Basidiomycete Lepista sordida. The structures were determined by the analysis of spectroscopic data including HREIMS and 1D and 2D NMR. The absolute configuration of lepistatin B was determined by comparing the specific rotation and circular dichroism spectrum with those of known structurally related compounds bearing the same chiral carbon. The structures of lepistatins A-C feature the indanone core structure, but differ from other indanone-containing sesquiterpenes of fungal origin by the alkyl substitution pattern. This indicates that lepistatins A-C probably possess a new sesquiterpene scaffold derived from the common precursor, trans-humulyl cation, by an alternative cyclization.
