7-Methylguanine is an orally available PARP1 inhibitor (Ki=61 μM) that competes with the substrate NAD+, exhibiting anticancer activity. As a natural nucleic acid metabolite, it may serve as a probe for protein-DNA interactions.

PARP-1:61 μM (Ki)

7-Methylguanine (0-200 μM) inhibits the activity of PARP1 enzyme in a dose-dependent manner [1].
7-Methylguanine is a competitive PARP-1 inhibitor with an inhibition constant (Ki value) of 61 μM [2].
7-Methylguanine (0-450 μM) suppresses the catalytic activity of PARP-1, thereby preventing the dissociation of the PARP-1-DNA complex [2].
After 24 hours of treatment with 7-Methylguanine (0.02-0.2 mg/mL), no DNA damage was observed in immortalized Homo sapiens renal epithelial cells (NKE-hTERT) [3].

In CBA, BALB/c, and C57BL/6 mice, 7-Methylguanine (50 mg/kg, administered orally, three times per week for 4 weeks) did not cause adverse reactions or morphological changes, while it inhibited tumor growth in CBA mice with uterine sarcoma US-322 [3].
In BALB/c mice transplanted with Akatol tumors, 7-Methylguanine (50 mg/kg, administered via gavage, three times per week) effectively penetrated tumor tissues and suppressed the growth of colon adenocarcinoma [5].