The main fraction V9 (5.0 g) from the first column eluted with pure ethyl acetate give two sub-fractions VY1-VY2 on further silica gel
column chromatography. The sub-fraction VY2 when further purified on silica gel column eluting with ethyl acetate: methanol (9: 1) yielded compound 4 (11 mg) and 5 (15 mg).
The crude residue was purified by silica-gel
column chromatography (hexanes-ethyl acetate, 9:1), to yield compound 10 (1.29 g, 5.37 mmol, 78%) as a white solid (mp 59-60 [degrees]C).
The residue was purified by
column chromatography (hexane/EtOAc, 9.5 : 0.5) to afford the pure Boc-protected amine 8 (14.7 g, 79%) as pale yellowish oil.
Usual work-up followed by purification of the resulting crude material by
column chromatography over silica gel afforded pure 2 (yield: 78%).
The crude products were isolated by
column chromatography to afford pure Michael adducts (7a-i).
The fungal mycelia were then separated from the broth by filtration, and the culture broth was then subjected to aromatic absorbent resin
column chromatography using Dianion HP-20 and elutecl with a step gradient of [H.sub.2]0 and MeOH as the mobile phase to afford 11 pooled fractions (1-11).
This disadvantage causes many labs to maintain both a
column chromatography method as well as an immunoassay method during initial patient screening.
The neutral fraction was subjected to silica gel
column chromatography and repeated p-HPLC to provide an active compound, (3[beta],24E)-lanosta-7,9(11),24-trien-3,26-diol (ganoderol B).
Column chromatography. The crude extract was fractionated using silica gel
column chromatography (column diameter 4.2 cm, height 35 cm) into its chemical constituents using a solvent system: hexane/diethyl ether; 2:1.
Purification of SK have already been studied by various methods including;
column chromatography on DEAE-cellulose followed by column electrophoresis in sucrose density gradients (15), a combination of ion exchange (DEAE-Sephadex A-50) and gel permeation (Sephadex G-100) chromatography (16).