Isolation and characterization of charge variants of infliximab biosimilar HS626.

Charge variants are the most commonly observed sources of heterogeneity in the routine manufacturing of monoclonal antibodies. To gain further insight into the structural foundation of charge heterogeneity and its influence on biological functions, an infliximab biosimilar HS626 from a biopharmaceutical facility was isolated by semipreparative cation exchange chromatography (CEX) to obtain fractions of acidic and basic charge variants and determine the main species. It was assessed again by CEX to ensure purities. Through a series of structural and physicochemical characterizations, we concluded that the acidic variants were caused by fragments, Met oxidation, Asn deamidation, higher levels of sialylation and galactosylation of N-linked glycans, and less high mannose. The basic variants resulted mainly from aggregates, fragments, and Met oxidation. Through further analysis of antigen binding affinity, cell death inhibitory activity, ADCC, and CDC, as well as FcRn, FcγRIIIa, and C1q affinity, we demonstrated that the charge heterogeneity did not affect biological functions. This research enhances the understanding of charge variants, which are usually effective components that should not be intentionally reduced unless biological functions are affected.

[Flavonoid glycosides from dried and nearly ripe fruits of Evodia rutaecarpa].

OBJECTIVE: To study the chemical constituents from the dried and nearly ripe fruits of Evodia (Euodia) rutaecarpa. METHOD: The compounds were separated and purified by solvent and chromatographic methods. Their structures were identified by spectroscopic techniques. RESULT: Fifteen compounds were separated from the normal butanol extracts of the 70% aqueous ethanol extract of the dried and nearly ripe fruits of E. rutaecarpa. Among of them, four compounds were reported in the essay and identified as diosmetin-7-O-beta-D-glucopyranoside (1), isorhamnetin-3-O-rutinoside (2), diosmin (3) and chrysoeriol-7-O-rutinoside (4). CONCLUSION: Compounds 1, 3 and 4 were separated from the dried and nearly ripe fruits of E. rutaecarpa for the first time.

New glycosidic alkaloid from the nearly ripe fruits of Euodia rutaecarpa.

A new natural product, 10-hydroxyrutaecarpine (1), and a rarely new glycosidic alkaloid, rutaecarpine-10-O-rutinoside (2), along with the known compounds rutaecarpine (3), evodiamine, wuzhuyuamide-I, and dehydroevodiamine were isolated from the butanol fraction of 70% ethanol aqueous extract of the dried and nearly ripe fruits of Euodia rutaecarpa (Juss.) Benth. Their structures were elucidated on the basis of their spectroscopic data.

Simultaneous determination and pharmacokinetic analysis of seven alkaloids and two flavonoids from rat plasma by HPLC-DAD after oral administration of Wuzhuyu decoction.

A simple and sensitive high-performance liquid chromatographic method was developed for the simultaneous determination and pharmacokinetic analysis of seven alkaloids dehydroevodiamine (DHED), 10-hydroxyrutaecarpine (HDR), evodiamine (EDM), rutaecarpine (RCP), 1-methyl-2-n-nonyl-4(1H)quinolone (MNQ), evocarpine (ECP), and dihydroevocarpine (DHE), and two flavonoids isorhamnetin-7-O-rutinoside (RIM) and diosmetin-7-O-ß-d-glucopyranoside (GRD) in rat plasma after oral administration of Wuzhuyu decoction. The flow rate was kept at 1.0 ml/min and the detection wavelength was set at 300 nm. The calibration curves were linear in the range of 0.5013-30.076 µg/ml for DHED, 0.2161-21.608 µg/ml for RIM, 0.161-12.876 µg/ml for HDR, 0.2146-21.457 µg/ml for GRD, 2.0464-40.928 µg/ml for EDM, 1.0398-31.194 µg/ml for RCP, 0.5970-35.818 µg/ml for MNQ, 0.8371-20.928 µg/ml for ECP, and 0.5167-31.003 µg/ml for DHE. The precision (relative standard deviation (RSD), %) for all was less than 10% and the accuracy (relative error (RE), %) was within ± 10%. The results demonstrated that the assay had remarkable reproducibility with acceptable accuracy and precision. The lower limit of quantifications for the compounds in plasma ranged from 0.12 to 0.23 µg/ml and the lower limit of detections ranged from 0.024 to 0.076 µg/ml. This validated method has been successfully applied in the pharmacokinetics study of seven alkaloids and two flavonoids after orally administrating the Wuzhuyu decoction to rats.