10367. Bisbenzimide

Nomenclature

CAS number: 23491-44-3
4-[5-(4-Methyl-1-piperazinyl)[2,5′-bi-1H-benzimidazol]-2′-yl]phenol; bisbenzimidazole; 2-[2-(4-hydroxyphenyl)-6-benzimidazoyl]-6-(1-methyl-4-piperazyl)benzimidazole; 2′-(4-hydroxyphenyl)-5-(4-methyl-1-piperazinyl)-2-5′-bi(1H-benzimidazole); pibenzimol.
C25H24N6O; mol wt 424.50.
C 70.73%, H 5.70%, N 19.80%, O 3.77%.

Description and references

Membrane-permeable dye and nuclear stain utilized in numerous cytological applications. Binds to A-T rich DNA sequences with blue fluorescence. Prepn: FR 1519964; H. Loewe et al., US 3538097 (1967, 1970 both to Hoechst). DNA staining: I. Hilwig, A. Gropp, Exp. Cell Res. 75, 122 (1972) DOI PubMed. Counterstaining applications: S. A. Schnell, M. W. Wessendorf, Histochemistry 103, 111 (1995) DOI. Fluorescence spectroscopic DNA binding studies: Y. Kubota, Bull. Chem. Soc. Jpn. 63, 758 (1990) DOI; A. Adhikary et al., Nucleic Acids Res. 31, 2178 (2003) DOI PubMed; and photophysical properties: G. Cosa et al., Photochem. Photobiol. 73, 585 (2001) DOI PubMed. DNA quantification assays: C. F. Cesarone et al., Anal. Biochem. 100, 188 (1979) DOI PubMed; D. L. Stout, F. F. Becker, ibid. 127, 302 (1982) DOI PubMed.

Chemical structure

Properties

mp 235° (dec). pKa1 ≈2; pKa2 3.49±0.03; pKa3 5.68±0.03; pKa4 7.94±0.05; pKa5 8.90±0.03; pKa6 11.69±0.06; pKa7 12.91±0.04. Sol in methanol.

Derivative

Trihydrochloride.

Nomenclature

CAS number: 23491-45-4
Bisbenzimide H 33258; Hoechst 33258; HOE 33258.
C25H24N6O.3HCl; mol wt 533.88.
C 56.24%, H 5.10%, N 15.74%, O 3.00%, Cl 19.92%.

Properties

mp 280° (dec). Irritant. Light sensitive. Sol in DMF, methanol. Soly in water: 2%. Will precipitate in phosphate buffer solns. As pentahydrate, abs max: 337 nm; 349 nm (complexed to ssDNA); 349 nm (complexed to dsDNA). Emission max: 508 nm; 466 nm (complexed to ssDNA); 458 nm (complexed to dsDNA).

Derivative

Ethoxide.

Nomenclature

CAS number: 23491-52-3
2′-(4-Ethoxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5′-bi-1H-benzimidazole.
C27H28N6O; mol wt 452.55.
C 71.66%, H 6.24%, N 18.57%, O 3.54%.

Properties

mp 268° (sesquihydrate).

Derivative

Ethoxide Trihydrochloride.

Nomenclature

CAS number: 875756-97-1
Bisbenzimide H 33342; Hoechst 33342; HOE 33342.
C27H28N6O.3HCl; mol wt 561.93.
C 57.71%, H 5.56%, N 14.96%, O 2.85%, Cl 18.93%.

Description and references

Fluorescent probe for membrane permeability studies: M. E. Lalande et al., Proc. Natl. Acad. Sci. USA 78, 363 (1981) DOI PubMed; for stem cell differentiation studies: I. Bertoncello, B. Williams, Methods Mol. Biol. 263, 181 (2004) PubMed.

Properties

Dark yellow powder. Irritant. Light sensitive. Hygroscopic. Sol in water, DMF. As pentahydrate, abs max: 336 nm; 350 nm (complexed to ssDNA); 350 nm (complexed to dsDNA). Emission max: 471 nm; 466 nm (complexed to ssDNA); 456 nm (complexed to dsDNA).

Use

Fluorescent cytological stain for DNA, flow cytometry, microscopy, immunostaining, autoradiography, nuclear counterstaining, and in situ hybridization. In assays to quantify DNA and to detect apoptosis. Probe for cellular differentiation and for membrane permeability.