Ocean is a unique and excellent resource that provides a diverse array of intriguing natural products. Marine natural products have demonstrated significant and extremely potent biological activities and have captured the attention of natural products chemists in the past few decades. It is increasingly recognized that a wealth of fascinating natural products and novel chemical entities will play a dominant role in the discovery of useful leads for the development of pharmaceutical agents and provide useful probes to lead to breakthroughs in a variety of life-science fields. This article focused on the research progress of chemistry of marine natural products in recent five years.

Objective To establish a separation method of loganin and morroniside reference substance from Fructus Corni. Methods After extracted with hot water and precipitated with alcohol, the extract of Fructus Corni was isolated and purified by macroporous resin, silica gel column chromatography, and preparative HPLC. Loganin and morroniside were identified by UV, 1H-NMR, 13C-NMR, and MS. Results The contents of loganin and morroniside was higher than 98% by normalization method of HPLC. Conclusion The developed method is simple with lower cost, by which loganin and morroniside can be used as reference substances for the qualitative and quantitative analysis of Chinese herbal medicine.

Some new types of microemulsion using phospholipids as the main surfactant were prepared for electrokinetic chromatography and the quantitative structure-retention relationship of neutral solutes in these microemulsion electrokinetic chromatography (MEEKC) systems was studied by solvation parameters model.By using dynamic coating capillary, and with dimethyl sulfoxide (DMSO) and dodecyl benzene as the marker of electroosmotic flow and microemulsion droplets, a total of 17 kinds of stable microemulsions containing soybean phospholipids or other surfactants were prepared and the linear salvation energy relationship equations were developed for these MEEKC systems with 26 small neutral compounds.The coefficients of linear solvation energy relationship (LSER) equations were used to evaluate the similarity of two MEEKC systems.Results indicated that LSER characteristics of phospholipids-MEEKC systems were similar to those of other microemulsion systems.The volume and hydrogen bond basicity of solutes were mostly contributed to the retention in MEEKC.The different types and concentration of oil phase had no evident influence on the retention.

OBJECTIVETo investigate the microbiological transformation of paeoniflorin and albiflorin.

METHODThe bacteria strains able to transform paeoniflorin and albiflorin were screened from 18 strains of microorganisms. The products were isolated by chromatography method and their structures were elucidated by spectral technology.

RESULTIt was found that Cunninghamella blakesleana (AS 3.970) and Syncephalastrum racemosum (AS 3.264) could convert paeoniflorin and albiflorin efficiently, respectively. C. blakesleana could convert paeoniflorin to produce albiflorin, while S. racemosum could convert albiflorin to produce paeoniflorin.

CONCLUSIONPaeoniflorin and albiflorin could be converted each other in definited condition.

Benzoates ; metabolism ; Biotransformation ; Bridged-Ring Compounds ; metabolism ; Cunninghamella ; metabolism ; Glucosides ; metabolism ; Monoterpenes ; Mucorales ; metabolism