Studies On The Chemical Composition Of Two Soft Corals From South China Sea

ObjectiveMarine-derived natural products have the characteristics of chemical structural diversity and biological activity diversity,and have played an important role in the research and development of new drugs and the discovery of new drug lead compounds for a long time.In order to find marine natural products with novel structure and good biological activity,two kinds of marine invertebrates(short-finger soft coral Sinularia hirta and Sarcophyton sp.Research of ingredients.MethodsThe thawed coral samples were chopped and sonicated to colorless with acetone.After concentration under reduced pressure,the organic solvent was removed.After that,the concentrate was suspended in water and extracted with equal volumes of ether and n-butanol solution.The solution was concentrated under reduced pressure again to obtain a crude extract of diethyl ether and n-butanol.The crude ether extract was chromatographed on a silica gel column and eluted with a gradient of petroleum ether-ether(PE-EE)and dichloromethane-methanol(DCM-Me OH)systems.The crude n-butanol extract was spotted for later use.Each component of the crude ether extract after gradient elution was separated and purified by silica gel column chromatography,gel permeation chromatography,semi-preparation,and chiral HPLC chromatography to obtain monomer compounds.Then,the NMR and MS diagrams of these monomer compounds were tested to determine their planar structures,and the three-dimensional configuration of the compounds was identified by calculating the carbon spectrum,ECD,and biological source derivation to determine the chemical structures of these compounds.Finally,the identified monomer compounds were tested for their antitumor activity.ResultsFrom Coral 06-YAL-50,there are 29 compounds,including 14 new compounds,including a new skeleton,7 Xeniaphyllane-type diterpenes,1 Norxeniaphyllane-type diterpenoids,and 1 Caryophyllane-type sesquiterpenes.Compounds,2 Norcaryophyllane-type sesquiterpene compounds and 2 Norhumulene-type sesquiterpene compounds.The planar structure was determined by 1D-NMR and mass spectrometry,and the relative and absolute configurations of Xeniaphyllane and Norhumulene-type compounds were determined by 2D-NMR,carbon spectrum calculation,and ECD calculation.The inhibitory effect of the obtained compounds on tumor cells was studied,and it was found that the compounds A-1,A-5,A-6,A-7,A-9,A-10,A-13,and A-14 had effects on lung cancer(A549),colon cancer(HT-29),liver cancer(SNU-398)and pancreatic cancer(Capan-1)have a certain inhibitory effect.Nine compounds were also isolated from Coral 18-XD-14,including a new Chatancin-type compound and two cimetanane dimers.ConclusionsIn this study,38 compounds were extracted and purified from 2 coral species in the South China Sea,including 15 new monomer compounds,including a new skeleton.Compounds A-2 and A-3 are relative configurations determined by calculating a carbon spectrum,and compounds A-2,A-3,and A-4 are absolute configurations determined by calculating an ECD.And it was found that compounds A-1,A-5,A-6,A-7,A-9,A-10,A-13,A-14 have a certain amount of tumor cell activity.The research on the chemical composition of two coral species in the South China Sea shows that the secondary metabolites of corals in the South China Sea have rich chemical diversity,which is conducive to the further development and utilization of China’s marine resources.