Description: <p>
<strong>HDN-1</strong> is a naturally occurring fungal
epipolythiodioxopiperazine / epipolythiopiperazine-2,5-dione
(<strong>ETP</strong>) isolated from the Antarctic fungus
<em>Oidiodendron truncatum</em> GW3-13. HDN-1 has demonstrated preclinical
anticancer activity and acts as a direct <strong>Hsp90 inhibitor</strong>,
binding the C-terminal region of Hsp90α. Hsp90 inhibition by HDN-1 promotes
degradation of multiple oncogenic client proteins, enhances downregulation of
wild-type and mutant EGFR and suppresses tumour-cell proliferation. HDN-1 has
also induced differentiation followed by apoptosis in selected promyelocytic
leukemia cell lines. Its mechanism overlaps with that of the structurally
related ETP chaetocin, which also inhibits Hsp90, but HDN-1 and chaetocin are
chemically distinct compounds and should be maintained as separate products.
HDN-1 should be classified as an <strong>experimental natural fungal metabolite
/ epipolythiodioxopiperazine / Hsp90 inhibitor</strong>, with current anticancer
evidence predominantly preclinical.<br>
HDN-1 is an analogue of chaetocin, which is a fungal mycotoxin with histone methyltransferase SUV39H1 inhibitory activity<br>
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