Valinomycin

Valinomycin is a potassium-specific ionophore, the valinomycin-K⁺ complex can be incorporated into biological bilayer membranes with the hydrophobic surface of valinomycin, destroys the normal K⁺ gradient across the membrane, and as a result kills the cells, incorporating into liposomes can significantly reduces the cytotoxicity and enhances the targeting effect. Valinomycin exhibits antibiotic, antifungal, antiviral, antitumor and insecticidal efficacy, thus can be used for relevant research^[1][2]. In Vitro: Lipo-Valinomycin (1-100 μM, 24 h) suppresses the viability of HepG2 significantly in a concentration-dependent manner^[2].
Lipo-Valinomycin (15 μM, 12 h) degrades the mitochondrial membrane potential and induces apoptosis (23%) of HepG2^[2].

Valinomycin bioactivities^[1]

Bioactivity	Target	Efficacy
Antibacterial	Streptococcus pyogenes	MIC 0.02 µg/mL
	Clostridium sporogenes	MIC 8 µg/mL
	Enterococcus faecalis	MIC 0.39–0.78 µg/disk
	Streptococcus pneumoniae	MIC 0.39–0.78 µg/disk
	Micrococcus luteus	MIC 25–50 µg/disk
Antifungal	Candida albicans	MIC 0.39–0.78 µg/disk
	Cryptococcus neoformans	MIC 50–100 µg/disk
	Phytophthora capsici	IC50 15.9 µg/mL
	Botrytis cinerea	MIC 4 µg/mL
	Magnaporthe grisea	MIC 4 µg/mL
	Candida albicans	MIC 32 µg/mL
	Colletotrichum gloeosporioides	MIC 256 µg/mL
	Rhizoctonia solani	MIC 256 µg/mL
	Penicillium verrucosum	IC50 0.005 ng/mL
Antiviral	SARS-CoV	EC50 0.85 µM
	PRRSV	IC50 24 nM
	RSV	IC50 0.0015 µM
	MERS-CoV	IC50 84 nM
	HCoV-OC43	EC50 4.43 µM
	HCoV-NL63	EC50 1.89 µM
	MHV-A59	EC50 6.78 µM
	LACV	IC50 588 nM
	RVFV MP-12	IC50 41 nM
	HRV2	IC50 610 nM
	CVB3	IC50 971 nM
	ZIKV	IC50 78 nM
	KEYV	IC50 156 nM
	HCoV-229E	IC50 67 nM
	LASV	EC50 0.61 µM
	LCMV	EC50 0.15 µM
Antitumor	Human ovarian tumor cells CaOV-3	IC50 0.1 nM
	Murine P388 leukemia cancer cells	GI50 0.019 µg/mL
	Human ovary OVCAR-3 tumor cells	GI50 0.19 ng/mL
	Brain SF-295 tumor cells	GI50 0.35 ng/mL
	Renal A-498 carcinoma cells	GI50 1.9 ng/mL
	Lung NCI-H460 cancer cells	GI50 0.21 ng/mL
	Colon KM20L2 carcinoma cells	GI50 0.27 ng/mL
	Melanoma SK-MEL-5 cancer cells	GI50 0.26 ng/mL
	Rat C6 glioma cells	IC50 0.4 µM
	Human A2780 ovarian carcinoma cells	IC50 2.18 µM
	Human MCF-7 breast carcinoma cells	IC50 1.77 µM
	Human HepG2 hepatocellular carcinoma cells	IC50 0.0008 µM
	Human U251 glioma cells	IC50 7.6 nM

In Vivo: Lipo-Valinomycin (1-40 μg/g, i.v., every 2 days for 16 d) inhibits HepG2 tumor growth in nude mice^[2].