Chiral high‐performance liquid chromatography (HPLC) analysis of natural pericosine A, which appeared in literature first in 1977, from Periconia byssoides was conducted using a column CHIRALPAK® AD‐H to determine the enantiomeric composition of the original mixture which was found to be 68: 32 mixtures of (+)‐ and (−)‐enantiomer, respectively. Furthermore, two independently isolated samples of pericosine A from the same fungus were also analyzed to show the two peaks in the HPLC charts at approximate 1:1 ratio. These results concluded that pericosine A derived from Periconia byssoides was indeed an enantiomeric mixture. Synthesized enantiomers were subjected to evaluation of antitumor activity against three kinds of tumor cells (p388, L1210, HL‐60), indicating moderate cytotoxicity against all three kinds of tumor cell lines, but significant difference in potency between the enantiomers was not observed. In contrast, when both the enantiomers of pericosine A were evaluated against five kinds of glycosidases‐inhibitory activities (α‐ and β‐glucosidases, α‐ and β‐galactosidases, and α‐mannosidase), an apparent difference on anti‐glycosidase assay was found between the enantiomers: (−)‐pericosine A inhibited α‐glucosidase at IC50: 2.25 mM, and β‐galactosidase at IC50: 5.38 mM, albeit the (+)‐enantiomer showed inactivity against these five enzymes.

The enantiomers of 6-fluoro-, 6-bromo-, and 6-iodopericosine A were synthesized. An efficient synthesis of both enantiomers of pericoxide via 6-bromopericosine A was also developed. These 6-halo-substituted pericosine A derivatives were evaluated in terms of their antitumor activity against three types of tumor cells (p388, L1210, and HL-60) and glycosidase inhibitory activity. The bromo- and iodo-congeners exhibited moderate antitumor activity similar to pericosine A against the three types of tumor cell lines studied. The fluorinated compound was less active than the others, including pericosine A. In the antitumor assay, no significant difference in potency between the enantiomers was observed for any of the halogenated compounds. Meanwhile, the (−)-6-fluoro- and (−)-6-bromo-congeners inhibited -glucosidase to a greater extent than those of their corresponding (+)-enantiomers, whereas (+)-iodopericosine A showed increased activity when compared to its (−)-enantiomer.