Poster Presenter

Inhibition Of Protein Tyrosine Phosphatase 1β By Hispidin Derivatives Isolated From The Fruiting Body Of Phellinus Linteus
Xing Fu Yin, Jeong Eun Kim , Yeon Sil Lee, Il-Jun Kang1, and Soon Sung Lim
Republic of Korea

Protein tyrosine phosphatase 1β (PTP1β) acts as a negative regulator of insulin signaling. Selective inhibition of PTP1β has served as a potential drug target for the treatment of type 2 diabetes mellitus. We evaluated the inhibitory effect of Phellinus linteus against PTP1β as part of our ongoing search for natural therapeutic and preventive agents for diabetes mellitus. The fractions of the P. linteus extract were found to exhibit significant inhibitory activities against PTP1β. In an attempt to identify bioactive components, we isolated, from the most active ethyl acetate fraction, 6 hispidin derivatives (hispidin, davallialactone, hypholomine B, interfungins A, inoscavin A, and phelligridimer A) and 4 phenolic compounds (protocatechuic acid, protocatechualdehyde, caffeic acid, and ellagic acid); we elucidated the chemical structures therein on the basis of spectroscopic evidence and compared with published data. All compounds strongly inhibited PTP1β activity in an in vitro assay; their IC50 values ranged from 8.97 ± 0.01 to 58.22 ± 0.34 μM. Our results indicated that the hispidin skeleton may be an important moiety for inhibitory activity of the above compounds against PTP1β. Thus, hispidin derivatives could be a potent new class of natural PTP1β inhibitors.