I am trying to get the dry form of streptomyces metabolites and since I will be testing their effect on specific cell lines, i need to dissolve them in a solvent that doesn’t effect the cells .
After getting the media filtrate ( cell free media ), liquid-liquid extraction was performed using ethyl acetate solvent and after shaking, i took the organic layer and dried it.
the problem now is in dissolving the dry ethyl acetate extract , several solvents were tested like DMSO, methanol, distilled water and growth media , but the metabolites didn’t dissolve in any of them .
what could be the possible reason for that ? And what should I do in this case ?
plus when doing the evaporation step I used the rotary evaporator but it was not practical as after evaporation I get a sticking residue which I have to collect using the solvent ethyl acetate again , what is the point of drying the solvent and adding It again to collect the sample afterwards ?