New technique to isolate anthocyanins from Delaware grapes by forming an aluminium complex using a Discovery DPA-6S.

An aluminium complex of crude Delaware grape anthocyanins, bearing an ortho-dihydroxyl group on the B ring and/or a p-coumaroyl group as an ester with flavocommelin, was formed and isolated by ethanol precipitation. Using a Discovery DPA-6S short column, selected anthocyanins were isolated to give cyanidin 3-glucoside (Cy3G, 48.2% yield with 95.2% purity) and cyanidin 3-(6-O-p-coumaroylglucoside) (Cy3-pC·G, 44.9% yield with 91.4% purity) from natural Delaware grape skin extracts without ODS-HPLC column chromatography. DPPH radical scavenging activity of the complex pigment was 3.4 ± 0.10 µmol TE/mg. Moreover, isolated pure anthocyanins from the complex pigment showed significantly higher DPPH radical scavenging activity [4.5 ± 0.08 µmol TE/mg (Cy3G) and 4.5 ± 0.04 µmol TE/mg (Cy3-pC·G), (p<0.05)].

Isolation techniques for anthocyanidin 3,5-diglucosides and their related chemicals using supramolecules technique, and two solid-phase extraction cartridges.

Isolation techniques for anthocyanidin 3,5-diglucosides and their derivatives from three types of supramolecular pigments were newly developed using two SPE (Discovery DPA-6S and DSC-SCX) cartridges. Initially, malonylawobanin from commelinin supramolecular complex yielded 79.5% with 85.7% purity using DPA-6S, while DSC-SCX gave a rather lower yield (62.5%) of malonylawobanin with high purity (90.8%). Delphinidin 3,5-diglucoside and awobanin from acidic hydrolysis of commelinin were easily separated using DPA-6S. Secondary, artificial Perilla supramolecules (reconstructed from Perilla crude pigment, flavocommelin and Mg(2+)) result in a high purity of a malonylshisonin and shisonin mixture (96.1%) with DSC-SCX. Finally, succinylcyanin, which is a component of protocyanin, yielded 64.3% with 86.1% purity using DPA-6S and 51.8% with 74.1% purity using DSC-SCX. Moreover, cyanidin 3,5-diglucoside yielded 43.4% with 97.0% purity using DPA-6S after partial acidic hydrolysis of protocyanin.

Rosmarinic acid extract for antioxidant, antiallergic, and α-glucosidase inhibitory activities, isolated by supramolecular technique and solvent extraction from Perilla leaves.

Rosmarinic acid extract with potent biological activities was successfully isolated by supramolecular technique and solvent extraction from Perilla leaves. By the supramolecular complex which was formed from flavocommelin and Perilla leaf extract as initial materials, the supernatant containing rosmarinic acid was isolated. Rosmarinic acid extract (62.9 ± 4.5% purity) was partly purified by partitioning ethyl acetate and water. Rosmarinic acid extract exhibited high total phenolic content of 433.9 ± 58.6 µg/mg of gallic acid equivalent, effective DPPH radical scavenging activity (SC50 of 5.5 ± 0.2 µg/mL), antiallergic activity (IC50 of 52.9 ± 6.7 µg/mL), and α-glucosidase inhibitory activity (IC50 of 0.23 ± 0.01 mg/mL). Rosmarinic acid extract shows high potential for diabetes mellitus and allergy treatments by inhibiting α-glucosidase activity and measuring ß-hexosaminidase, related to life-style disease.

Isolation of bilberry anthocyanidin 3-glycosides bearing ortho-dihydroxyl groups on the B ring by forming an aluminum complex and their antioxidant activity.

Bilberry anthocyanin bearing an ortho-dihydroxyl group on the B ring was selectively isolated by complex formation with flavocommelin and aluminum ions (Al(3+)). The interaction between the anthocyanins, flavocommelin, and Al(3+) might have happened in a manner similar to rigid supramolecules, such as commelinin, protocyanin, and other complex pigments. Complex blue pigment (CP, 8.85 ± 0.26 mg) with Al(3+) was formed from 18.6 mg (15 µmol) of bilberry pigment, 18.2 mg (30 µmol, 2.0 equiv) of flavocommelin, and 0.03 mL of 0.5 M aluminum chloride aqueous solution (15 µmol, 1.0 equiv), yielding 36.5 ± 0.7% recovery of anthocyanins in the complex after precipitation by ethanol. Consequently, anthocyanins bearing ortho-dihydroxyl groups on the B rings (delphinidin 3-glycosides, cyanidin 3-glycosides, and petunidin 3-glycosides) predominating (98.0 ± 0.2%) in the complex were selectively isolated in a dose-dependent manner by the addition of Al(3+), increasing the antioxidative activity of the mixture of anthocyanins.

Enzymatic saccharification of Eucalyptus bark using hydrothermal pre-treatment with carbon dioxide.

In this study, saccharification of the inner bark of Eucalyptus was carried out by enzymatic hydrolysis to produce bioethanol from non-food biomass. To enhance the accessibility of the enzyme to the polysaccharides such as cellulose and holocellulose in the cell wall of the bark, the bark was subjected to hydrothermal pre-treatment with carbon dioxide. This pre-treatment considerably influenced enzymatic hydrolysis. The main component (over 90%) of the generated monosaccharide was glucose, and the yield of glucose on the basis of alpha-cellulose reaches about 80%. This result suggests that the secondary wall, whose main component is cellulose, was effectively hydrolyzed by the enzyme. Microscopic analysis revealed that after pre-treatment, the phloem parenchyma cell had a considerably swollen primary wall and the phloem fibre showed many nano-clefts within its secondary wall. These structural changes appeared to promote enzymatic hydrolysis, because of high accessibility of enzymes to cellulose in the secondary wall.