The present invention provides di-substituted acetalanthraquinone-based compounds of the Formulae (l)-(IV) that are useful for cellular staining and for light-based detection of biological material, e.g. fluorescence-based detection of biological material. These compounds may be used in hydrolysed or non-hydrolysed form. Also provided is a fluorescent complex that comprises a nucleic acid and an acetalanthraquinone-based compound of the invention; and a method of staining a biological sample comprising cells or other biological material containing nucleic acid, which method comprises contacting the biological sample with an acetalanthraquinone-based compound of the invention. In the Formulae (l)-(IV), A and B are each independently of formula —R.sup.aCH.sub.2CH(OR.sup.b).sub.2; or one of A and B is of formula —R.sup.aCH.sub.2CH(OR.sup.b).sub.2 and the other one is of formula: —NR.sup.b.sub.2. ##STR00001##

The present invention provides di-substituted acetalanthraquinone-based compounds of the Formulae (l)-(IV) that are useful for cellular staining and for light-based detection of biological material, e.g. fluorescence-based detection of biological material. These compounds may be used in hydrolysed or non-hydrolysed form. Also provided is a fluorescent complex that comprises a nucleic acid and an acetalanthraquinone-based compound of the invention; and a method of staining a biological sample comprising cells or other biological material containing nucleic acid, which method comprises contacting the biological sample with an acetalanthraquinone-based compound of the invention. In the Formulae (l)-(IV), A and B are each independently of formula —R.sup.aCH.sub.2CH(OR.sup.b).sub.2; or one of A and B is of formula —R.sup.aCH.sub.2CH(OR.sup.b).sub.2 and the other one is of formula: —NR.sup.b.sub.2. ##STR00001##

The present invention relates to a compound of formula (I-0) or a salt thereof. The invention further relates to the use of such compound as a colouring agent. The invention also relates to a colouring composition comprising such compound.

The present invention pertains to: a liquid crystal composition for controlling light that contains, as a dichroic dye, an anthraquinone compound having a specific structure; and a light-controlling element that contains a cured product of said liquid crystal composition for controlling light and exhibits excellent contrast, light-blocking performance, lightfastness, and heat tolerance during current supply. More specifically, the present invention pertains to: a liquid crystal composition for controlling light that contains a compound represented by formula (A) (in the formula. R1 represents a C1-12 alkyl group or a C1-12 alkoxy group, and each R2 independently represents a C1-8 alkyl group), a liquid crystal material, a photocurable compound, and a photoinitiator; and a light-controlling element that is formed by sandwiching a photocured product of said composition between a pair of substrates.

##STR00001##

The present invention pertains to: a liquid crystal composition for controlling light that contains, as a dichroic dye, an anthraquinone compound having a specific structure; and a light-controlling element that contains a cured product of said liquid crystal composition for controlling light and exhibits excellent contrast, light-blocking performance, lightfastness, and heat tolerance during current supply. More specifically, the present invention pertains to: a liquid crystal composition for controlling light that contains a compound represented by formula (A) (in the formula, R1 represents a C4-12 alkyl group or a C4-12 alkoxy group, and each R2 independently represents a C6-12 alkyl group), a liquid crystal material, a photocurable compound, and a photoinitiator; and a light-controlling element that is formed by sandwiching a photocured product of said composition between a pair of substrates.

##STR00001##

The present invention provides di-substituted acetalanthraquinone-based compounds of the Formulae (l)-(IV) that are useful for cellular staining and for light-based detection of biological material, e.g. fluorescence-based detection of biological material. These compounds may be used in hydrolysed or non-hydrolysed form. Also provided is a fluorescent complex that comprises a nucleic acid and an acetalanthraquinone-based compound of the invention; and a method of staining a biological sample comprising cells or other biological material containing nucleic acid, which method comprises contacting the biological sample with an acetalanthraquinone-based compound of the invention. In the Formulae (l)-(IV), A and B are each independently of formula R.sup.aCH.sub.2CH(OR.sup.b).sub.2; or one of A and B is of formula R.sup.aCH.sub.2CH(OR.sup.b).sub.2 and the other one is of formula: NR.sup.b.sub.2.

##STR00001##

The present invention provides di-substituted acetalanthraquinone-based compounds of the Formulae (l)-(IV) that are useful for cellular staining and for light-based detection of biological material, e.g. fluorescence-based detection of biological material. These compounds may be used in hydrolysed or non-hydrolysed form. Also provided is a fluorescent complex that comprises a nucleic acid and an acetalanthraquinone-based compound of the invention; and a method of staining a biological sample comprising cells or other biological material containing nucleic acid, which method comprises contacting the biological sample with an acetalanthraquinone-based compound of the invention. In the Formulae (l)-(IV), A and B are each independently of formula R.sup.aCH.sub.2CH(OR.sup.b).sub.2; or one of A and B is of formula R.sup.aCH.sub.2CH(OR.sup.b).sub.2 and the other one is of formula: NR.sup.b.sub.2.

##STR00001##

The present invention pertains to: a liquid crystal composition for controlling light that contains, as a dichroic dye, an anthraquinone compound having a specific structure; and a light-controlling element that contains a cured product of said liquid crystal composition for controlling light and exhibits excellent contrast, light-blocking performance, lightfastness, and heat tolerance during current supply. More specifically, the present invention pertains to: a liquid crystal composition for controlling light that contains a compound represented by formula (A) (in the formula, R1 represents a C4-12 alkyl group or a C4-12 alkoxy group, and each R2 independently represents a C6-12 alkyl group), a liquid crystal material, a photocurable compound, and a photoinitiator; and a light-controlling element that is formed by sandwiching a photocured product of said composition between a pair of substrates. ##STR00001##

The invention discloses new substituted anthraquinone dyes that may be useful as cellular stains. In some aspect of the invention, the nuclear stains are useful for staining the nuclei of dead or fixed cells. Another aspect of the invention relates to substituted anthraquinone dyes comprising an enzyme substrate moiety that is transformable or cleavable by an enzyme such that the transformation or cleavage of the substrate moiety causes a detectable change in the functionality or spectral properties of the dye.

The invention discloses new substituted anthraquinone dyes that may be useful as cellular stains. In some aspect of the invention, the nuclear stains are useful for staining the nuclei of dead or fixed cells. Another aspect of the invention relates to substituted anthraquinone dyes comprising an enzyme substrate moiety that is transformable or cleavable by an enzyme such that the transformation or cleavage of the substrate moiety causes a detectable change in the functionality or spectral properties of the dye.