The supernatant was collected, evaporated to remove ethyl alcohol using a vacuum rotavap
(RE-52AA, Shanghai Qingpu Huxi Instrument, China), and then diluted to 50 mL with distilled water to give the sample extract solution.
Solution was evaporated to dryness in rotavap
to remove adsorbed ammonia.
The mixture was evaporated in a rotavap
, and the remaining solid was washed with diethyl ether and dried three times.
To stop the back reaction, excess of alcohol is evaporated off by rotavap
. Residue is extracted with diethyl ether.
The resulting eluent was then moved to a flat bottom Florence flask (Corning, 4060-250), using the triple DCM rinsing technique, and rotary evaporated (Rotavap
Buchi Laboratory Equipment) until all excess DCM was removed.
Briefly, 80% methanol was mixed with ground GBR (4 : 1, solvent-to-GBR ratio) and incubated for 2 h in a sonicator (extraction was performed three times), and the resultant supernatants evaporated to dryness (Buchi R-210 rotary evaporator, Rotavap
1 filter paper and then evaporated to dryness under vacuum using rotary evaporator (BUCHI Rotavap
or R-114) at 40 degC to form a crude extract.
The process of simple distillation was performed in the recovery of acetone with the aid of a rotary evaporator or rotavap
(TE-210-Tecnal), which enabled the separation of the liquid (acetone) from the nonvolatile substances (residues).
The reaction mixture was retiuxed under stirring for about 3 h, after which the solvents were removed in rotavap
. The product was successively washed with chloroform and water and dried.
The solvent was removed on a rotavap
and the solid washed with water to give compound 3 (yield 98%), m.p.
The samples were concentrated under vacuum (Rotavap