Biotransformation Of Resveratrol And Curcumin By A Deep Marine Derived Funngus-Aspergillus Sp.SCSIOW2

It is well known that resveratrol and curcumin have extensive biological activity,such as anti-oxidation,anti-inflammatory,cardiovascular protection,and so on.Resveratrol is mainly derived from red grapes,mulberry and other plants.It is a polyphenol type compond.Curcumin is a yellow pigment extracted from the roots of turmeric,commonly used as food additives.The poor water solubility limited their further application.How to improve the bioavailability is an urgent problem to be solved.We studied the biotransformation of resveratrol and curcumin by fungi.Resveratrol and curcumin were added in the fermentation media of Aspergillus sp.SCSIOW2,respectively.After 7 days of co-fermentation,the fermentation products were extracted with ethyl acetate and acetone.The crude extracts were then purified by TLC and HPLC to obtain biotransformation products.Arahypin-16,a new prenylated resveratrol with a unique dihydrobenzofuran ring,has been isolated as a microbial metabolite of resveratrol from whole-cell fermentation of Aspergillus sp.SCSIOW2.The stereochemistry of Arahypin-16 was determined by ECD calculations.Arahypin-16 showed about half of the extracellular radical scavenging effect(EC50 = 161.4 ?M)compared with resveratrol(EC50 = 80.5 ?M),while on biomembranes it exhibited the same range of protection effects against free radicals generated from AAPH(IC50 = 78.6 ?M and 87.9 ?M).We also found another prenylated resveratrol compond:trans-3?-isopentadienyl-3,5,4?-trihydroxystilbene.3 transformation product was obtained by biotransformation of curcumin in Aspergillus sp.SCSIOW2.By NMR and HRMS spectroscopy,the structure of this compound was determined as hexahydrocurcumin?3,5-Heptanediol,1,7-bis(4-hydroxy-3-methoxyphenyl)-(3R,5R)and 3,5-Heptanediol,1,7-bis(4-hydroxy-3-Methoxyp henyl)-(3R,5S).Hexahydrocurcumin is stronger in extracellular DPPH free radical scavenging efficiency(EC50 = 94.4?M)than curcumin(EC50 = 140.5 ?M).In the AAPH: hexahydrocurcumin(EC50 = 38.4 ?M)activity was similar to curcumin(EC50 = 22.8 ?M)and they are present in a concentration-dependent manner.