9-Amino-6-chloro-2-methoxyacridine

9-Amino-6-chloro-2-methoxyacridine (ACMA) is a multifunctional, cell-permeable fluorescent probe and bioactive molecule that can be utilized as a DNA intercalator and a pH/membrane potential-sensitive probe^[1]. 9-Amino-6-chloro-2-methoxyacridine selectively binds to poly(dA-dT) sequences, and its fluorescence lifetime decreases upon the incorporation of guanosine. It is used for DNA labeling, exhibiting excitation/emission spectra of 411/475nm, respectively ^[2]. The fluorescence intensity of 9-Amino-6-chloro-2-methoxyacridine is pH-dependent and undergoes fluorescence quenching when a pH gradient is established—a property that has been applied in both animal and plant studies ^[3][4][5]. 9-Amino-6-chloro-2-methoxyacridine inhibits acetylcholinesterase with an inhibition constant (Kᵢ) of 49 nM ^[6]. Under photoactivation conditions, 9-Amino-6-chloro-2-methoxyacridine can also inhibit the proton-translocating activity of mitochondrial FoF₁-ATPase and is frequently employed in studies investigating cellular energy metabolism and photodynamic therapy mechanisms ^[7].

References:
[1]. Fukui K, Tanaka K, Fujitsuka M, et al. Distance dependence of electron transfer in acridine-intercalated DNA[J]. Journal of Photochemistry and Photobiology B: Biology, 1999, 50(1): 18-27.
[2]. Haerd T, Fan P, Magde D, et al. On the flexibility of DNA: time-resolved fluorescence polarization of intercalated quinacrine and 9-amino-6-chloro-2-methoxyacridine[J]. The Journal of Physical Chemistry, 1989, 93(10): 4338-4345.
[3]. Baracca A, Bucchi L, Ghelli A, et al. Protonophoric activity of NADH coenzyme Q reductase and ATP synthase in coupled submitochondrial particles from horse platelets[J]. Biochemical and biophysical research communications, 1997, 235(3): 469-473.
[4]. Uzdavinys P, Coinçon M, Nji E, et al. Dissecting the proton transport pathway in electrogenic Na+/H+ antiporters[J]. Proceedings of the National Academy of Sciences, 2017, 114(7): E1101-E1110.
[5]. Carqueijeiro I, Martins V, Noronha H, et al. Analytical and Fluorimetric Methods for the Characterization of the Transmembrane Transport of Specialized Metabolites in Plants[M]//Biotechnology of Plant Secondary Metabolism: Methods and Protocols. New York, NY: Springer New York, 2016: 121-135.
[6]. Bencharit S, Morton C L, Hyatt J L, et al. Crystal structure of human carboxylesterase 1 complexed with the Alzheimer's drug tacrine: from binding promiscuity to selective inhibition[J]. Chemistry & Biology, 2003, 10(4): 341-349.
[7]. Pravdic D, Hirata N, Barber L, et al. Complex I and ATP synthase mediate membrane depolarization and matrix acidification by isoflurane in mitochondria[J]. European journal of pharmacology, 2012, 690(1-3): 149-157.

9-Amino-6-chloro-2-methoxyacridine(ACMA)是一种多功能的细胞渗透性荧光探针和生物活性分子，可作为DNA嵌入剂和pH/膜电位敏感探针使用^[1]。9-Amino-6-chloro-2-methoxyacridine可选择性地结合聚(dA-dT)序列，且荧光寿命随着鸟苷的掺入而降低。9-Amino-6-chloro-2-methoxyacridine用于标记DNA，其激发/发射光谱分别为411/475nm^[2]。9-Amino-6-chloro-2-methoxyacridine的荧光强度受pH值影响，并在建立pH梯度时发生荧光猝灭，这一特性已被应用于动植物研究中^{[3] [4] [5]}。9-Amino-6-chloro-2-methoxyacridine可抑制乙酰胆碱酯酶，Ki值为49nM^[6]。光激活条件下，9-Amino-6-chloro-2-methoxyacridine还可抑制线粒体FoF1-ATP酶的质子转运功能，常用于研究细胞能量代谢与光动力治疗机制^[7]。