Histone deacetylases (HDACs) have recently emerged as key elements in epigenetic control of
gene expression. Due to the implication of HDACs in a variety of diseases ranging from cancer to neurodegenerative
disorder, HDAC inhibitors have received increased attention in recent years. Over the last few
decades, a myriad of HDAC inhibitors containing a wide variety of structural features have been identified
from natural sources. Here, we review the discovery, synthesis, biological properties, and modes of action of
these naturally occurring HDAC inhibitors and consider their implications for future research.