Okicamelliaside, an extraordinarily potent anti-degranulation glucoside isolated from leaves of Camellia japonica.

Guided by anti-degranulation assays, we isolated from leaves of Camellia japonica an ellagic acid glucoside named okicamelliaside. The structure was elucidated as 3,4-dioxoloellagic acid 4'-O-β-D-glucopyranoside by spectroscopic and chemical methods. Okicamelliaside was 12,000 times more potent than the antihistaminic drug, ketotifen fumarate, in inhibiting the degranulation of RBL-2H3 cells.

Camellianoside, a novel antioxidant glycoside from the leaves of Camellia japonica.

A novel flavonol glycoside named camellianoside and three known flavonol glycosides were isolated from the leaves of Camellia japonica. The structure of camellianoside was established as quercetin-3-O-beta-D-xylopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->6)-O-beta-D-glucopyranoside by spectroscopic and chemical methods. The antioxidant activities of these glycosides evaluated by the diphenylpicrylhydrazyl (DPPH) radical scavenging reaction was higher than those of L-cysteine and L-ascorbic acid used as the reference antioxidants.

Baculovirus expression, purification, and characterization of human protein phosphatase 2A catalytic subunits alpha and beta.

Protein phosphatase 2A (PP2A) contains a 36-kDa catalytic subunit (PP2Ac), a 65-kDa structural subunit (PR65/A), and a regulatory B subunit. The core enzyme consists of the structural and catalytic subunits. The catalytic subunit exists as two closely related isoforms, alpha and beta.