Table 2.

Cyclic peptides and alkaloids with their epigenetic anticancer role.

Compound	Structural Formula	Chemical Class	Source	Species	Epigenetic Mechanism	Ref
Romidepsin		Depsipeptide	Bacterium	Chromobacterium violaceum	HDAC inhibition (in vitro)	[80,82,83,84]
Plitidepsin		Cyclic tetrapeptide	Tunicate	Aplidium albicans	Caspase-3 upregulation (in vitro)	[87]
					Dephosphorylation of ERK1/2 and 5 (in vitro)	[88]
PM01215			Aplidin analogues		p16INK4A induction (in vitro)	[89]
					VEGF downregulation (in vitro)
PM02781			Aplidin analogues		p16INK4A induction (in vitro)	[89]
Largazole		Macrocyclic depsipeptide	Cyanobacterium	Symplocasp	HDAC inhibition (in vitro)	[85,91]
					HDAC inhibition (in vivo)	[85]
Azumamides		Cyclic tetrapeptide	Sponge	Mycale izuensis	HDAC inhibition (in vitro)	[92,93,95]
					Increased H3 acetylation (in vitro)	[94]
Trapoxins		Cyclic tetrapeptide	Fungus	Helicoma ambiens	Class I HDAC inhibition (in vitro)	[96]
					HDAC inhibition (in vitro)	[97]
Apicidin		Cyclic tetrapeptide	Fungus	Fusarium pallidoroseum	HDAC8 inhibition (in vivo)	[98]
					p21 upregulation (in vitro)	[99]
					HDAC inhibition (in vitro)	[99,100]
					DNMT inhibition (in vitro)	[42]
					HDACs2/3 inhibition (in vitro)	[42]
Microsporins A and B		Cyclic peptide	Fungus	Microsporum cf. gypseum	HDAC inhibition (in vitro)	[101]
					HDAC8 inhibition (in vitro)
Isofistularin-3		Alkaloid	Sponge	Aplysina aerophoba	DNMT1 inhibition (in vitro)	[33]
Cyclostellettamines		Alkaloid	Sponge	Xestospongia	HDAC inhibition (in vitro)	[102,103]