Preparation and quality evaluation of bryostatins freeze-dried liposomes / 第二军医大学学报

Objective:To prepare bryostatins freeze-dried liposomes and to establish a quality standard for the liposomes.Methods: Film dispersion technique was used to encapsulate bryostatins with liposomes.Chloroform was taken as the solvent and was volatilized by revolving.Emulsification was performed with the probe after hydration,then the supporting agent was added for freeze drying.An RP-HPLC method was developed to determine the freeze-dried liposome content.The separation was performed with a Agilent C_(18) Column and the mobile phase was methanol-water in gradient elution 7525(0-38 min),(73.726.3)(38-45 min),7921(45-48 min) by a flow rate of 1.5 ml/min,with the UV detector set at 228 nm.Zetasizer was used to determine the size of liposomes and the entrapment efficiency was determined with centrifugal ultrafilter.Results: The freeze-dried liposomes were homogeneous and the mean diameter was 0.423 ?m.The standard curve was linear over the range of 44-220 ?g/ml,r=0.999 8.The intra-day and inter-day RSDs were less than 2.0%.The recoveries of the high,middle and low concentrations(88,110,and 132 ?g/ml) were 100.8%,98.4%,and 100.9%,respectively.The detection limit was 4.4 ng,the quantitation limit was 17.6 ng,and the entrapment efficiency was 98.68%.Conclusion: The film dispersion technique is(suitable) for preparation of bryostatins liposomes.The method in this study is easy-to-use,accurate,and with good(repeatability.)

Studies on antineoplastic constituents from marine bryozoan bugula neritina inhabiting south china sea (IV):Isolation and structural elucidation of bryostatins 8 and 16 / 中国海洋药物

Eight active compounds were isolated from Bugula neritina Linnaeus collected off Dapen Bay in Guandong province, guided by P 388 bioassay system by a combination of successive chromatographies and preparative HPLC. By intensive analysis of the data of high resolution 2D NMR spectrum and ESI MS, their structures were elucidated as known bryostatins--bryostatin 4, 5, 6, 8, 10, 11, 16 and 18, among which bryostatin 8 and 16 were for the first time obtained from this animal in South China Sea and they showed significant antineoplastic activities in vitro.

STUDIES ON THE ANTINEOPLASTIC CONSTITUENTS FROM MARINE BRYOZOAN BUGULA NERITINA IN THE SOUTH CHINA SEA( I ) / 中国海洋药物

Three active compounds were isolated from the marine bryozoan Bugula neritina living in the South China Sea by bioassay-guiding isolation method with a combination of extraction with suitable solvent and multiple column chromatography(Sephadex LH-20, ODS and preparative HPLC). Their structures were assigned as known bryostatin 4, bryostatin 5 and bryostatin 6 by intensive analysis of the data of high resolution 2DNMR(600 MHz,DQF-COSY,TOCSY,HMQC and ROESY). All these compounds were obtained from this bryozoan in the South China Sea for the first time and showed significant antineoplastic activities in vitro.