Table 2. Summary of small molecule compounds enhancing iPSC generation.

Name	Targets	Effects	Ref
Chemicals protomoting reprogramming
Epigenetic modifiers
Valproic acid	HDAC inhibitor	Promote KOS-induced reprogramming, enable the reprogramming of human fibroblasts transduced by OS	56,57
TSA	HDAC inhibitor	Promote OSKM-induced reprogramming	56
SAHA	HDAC inhibitor	Promote OSKM-induced reprogramming	56
RG108	DNMT inhibitor	In combination with BIX to improve KO-induced MEF reprogramming	58
5-AZA	DNMT inhibitor	Promote OSKM-induced reprogramming	56
BIX-01294	HMTase G9a inhibitor	Promote reprogramming of NPCs and MEFs transduced by OK	58,102
Parnate	LSD1 inhibitor	Enable the reprogramming of human keratinocytes transduced by OK	59
LiCl	Inhibitor of LSD1 and GSK3	Promote MEF reprogramming by OSKM	60
Vitamin C	Vitamin-C-dependent H3K36 demethylase (Jhdm1a/1b), antioxident, p53, senescence	Enhance iPSC generation from both mouse and human somatic cells	91
Anisomycin and TNF-α	Activation of p38, reducing the global DNA methylation	Promote MEF reprogramming by OSKM	62
EMT/MET modulators
SB-431542	ALK4/5/7 inhibitor	Replace c-myc or Sox2 to promote MEF reprogramming	69
E-616452 (RepSox)	ALK5 inhibitor	Promote reprogramming, replace Sox2 in reprogramming	70
A-83-01	ALK5 inhibitor	Combined with MEK and Rock inhibitors to improve human fibroblast reprogramming; support rat iPSC long-term selfrenewal when combined with CHIR99021 and PD0325901	68,103
Thiazovivin	ROCK inhibitor	Increase reprogramming efficiency and accelerate reprogramming kinetics of human fibroblasts in conjunction with MEK and TGF inhibitors	103
Metabolic regulator (glycolysis pathway)
PS48	Activator of PDK1/PI3K/Akt	Promote human iPSC induction by Oct4 alone	75
Fructose 6-phosphate	Stimulate glycolytic metabolism	Promote human iPSC induction by Oct4 alone	75
Fructose 2,6-bisphosphate	Stimulate glycolytic metabolism	Promote human iPSC induction by Oct4 alone	75
Nicotinic acid	Stimulate glycolytic metabolism	Promote human iPSC induction by Oct4 alone	75
2-Hydroxyglutaric acid (2-HA)	Stimulate glycolytic metabolism	Promote human iPSC induction by Oct4 alone	75
Quercetin	HIF pathway activation	Promote human iPSC induction by Oct4 alone	75
N-oxaloylglycine (NOG)	HIF pathway activation	Promote human iPSC induction by Oct4 alone	75
2,4-dinitrophenol (DNP)	Uncouple the mitochondrial respiratory chain	Promote human iPSC induction by Oct4 alone	75
Other chemicals promoting reprogramming
(+)Bayk 8644	L-type Ca2+ channel	Promote MEF reprogramming in combination with G9a inhibition	58
CD437	RAR agonist	Promote OSKM-induced reprogramming	92
AM580	RAR agonist	Promote OSKM-induced reprogramming	92
Dexamethasone	Steroid glucocorticoid	Promote OSKM-induced reprogramming	56
Rapamycin	Inhibitor of mTOR	Promote OSKM-induced reprogramming	94
PP242	Inhibitor of mTOR	Promote OSKM-induced reprogramming	94
Resveratrol	Sirtuin activator	Promote OSKM-induced reprogramming	94
Fisetin	Sirtuin activator	Promote OSKM-induced reprogramming	94
Spermidine	An autophagy inducer	Promote OSKM-induced reprogramming	94
LY294002	PI3K inhibitor	Promote OSKM-induced reprogramming	94
Curcumin	An antioxidant	Promote OSKM-induced reprogramming	94
Chemicals facilitating self-renewal of stem cells
PD0325901+CHIR99021 (2i) Inhibitor of MEK and GK3 respectively		Eliminate differentiation of stem cells	87
6-Bromoindirubin-3′-oxime (BIO)	GSK-3 inhibitor IX	Maintain human and mouse ESCs in an undifferentiated state without feeder cells	88
Pluripotin/SC1	RasGAP and ERK1	Support mESC self-renewal	86
Y-27632	ROCK inhibitor	Enhance survival rate after cryopreservation and cloning efficiency of human ES and iPSCs	104

iPSC, induced pluripotent stem cell; K, Klf4; O, Oct4; M, c-Myc; S, Sox2