The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

The present disclosure provides γ-diketones or analogs thereof, that activate Wnt/β-catenin signaling and thus treat or prevent diseases related to signal transduction, such as osteoporosis and osteoarthropathy; osteogenesis imperfecta, bone defects, bone fractures, periodontal disease, otosclerosis, wound healing, craniofacial defects, oncolytic bone disease, traumatic brain injuries or spine injuries, brain atrophy/neurological disorders related to the differentiation and development of the central nervous system, including Parkinson's disease, strokes, ischemic cerebral disease, epilepsy, Alzheimer's disease, depression, bipolar disorder, schizophrenia; otic disorders like cochlear hair cell loss; eye diseases such as age related macular degeneration, diabetic macular edema or retinitis pigmentosa and diseases related to differentiation and growth of stem cell, such as hair loss, hematopoiesis related diseases and tissue regeneration related diseases.

The present disclosure provides γ-diketones or analogs thereof, that activate Wnt/β-catenin signaling and thus treat or prevent diseases related to signal transduction, such as osteoporosis and osteoarthropathy; osteogenesis imperfecta, bone defects, bone fractures, periodontal disease, otosclerosis, wound healing, craniofacial defects, oncolytic bone disease, traumatic brain injuries or spine injuries, brain atrophy/neurological disorders related to the differentiation and development of the central nervous system, including Parkinson's disease, strokes, ischemic cerebral disease, epilepsy, Alzheimer's disease, depression, bipolar disorder, schizophrenia; otic disorders like cochlear hair cell loss; eye diseases such as age related macular degeneration, diabetic macular edema or retinitis pigmentosa and diseases related to differentiation and growth of stem cell, such as hair loss, hematopoiesis related diseases and tissue regeneration related diseases.

Provided are a 1,3-di-substituted ketene compound having a structure as represented by formula (I) and an application thereof. Such a type of compound primarily activates peroxisome proliferator-activated receptor (PPAR) α, and also activates PPPAδ and PPPAγ. The compound may be used to treat various diseases associated with PPAR regulation and control abnormality, such as non-alcoholic fatty liver disease, and especially in treating non-alcoholic hepatitis, and may potentially be used in the treatment of diseases comprising diabetes, obesity, fibrotic diseases, cardiovascular diseases (comprising heart failure, atherosclerosis, and so on), kidney diseases (comprising chronic kidney disease, renal failure, and so on), and brain degenerative diseases (comprising Alzheimer's disease and so on), having great application value.

##STR00001##

Provided are a 1,3-di-substituted ketene compound having a structure as represented by formula (I) and an application thereof. Such a type of compound primarily activates peroxisome proliferator-activated receptor (PPAR) α, and also activates PPPAδ and PPPAγ. The compound may be used to treat various diseases associated with PPAR regulation and control abnormality, such as non-alcoholic fatty liver disease, and especially in treating non-alcoholic hepatitis, and may potentially be used in the treatment of diseases comprising diabetes, obesity, fibrotic diseases, cardiovascular diseases (comprising heart failure, atherosclerosis, and so on), kidney diseases (comprising chronic kidney disease, renal failure, and so on), and brain degenerative diseases (comprising Alzheimer's disease and so on), having great application value.

##STR00001##

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

A compound, or a pharmaceutically acceptable salt or ester thereof, having a formula I of:

R.sup.20(Z).sub.b(Y).sub.c(R.sup.21).sub.aXR.sup.22R.sup.23 wherein R.sup.20 is an aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocycloalkyl, substituted heterocycloalkyl, alkoxy, aryloxy, a silyl-containing group, a boryl-containing group, a phosphine-containing group, amino, a thio-containing group, a seleno-containing group, halide, or a nitro-containing group; Z is alkanediyl, substituted alkanediyl, cycloalkanediyl, or substituted cycloalkanediyl; Y is S, O, or NR.sup.10, wherein R.sup.10 is H or alkyl; R.sup.21 is alkanediyl, substituted alkanediyl, cycloalkanediyl, substituted cycloalkanediyl, alkadienyl, substituted alkadienyl, alkatrienyl, substituted alkatrienyl; X is C(O) or S(O)(O); R.sup.22 is a moiety that includes at least one divalent amino radical; R.sup.23 is an aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocycloalkyl, substituted heterocycloalkyl, alkoxy, aryloxy, a silyl-containing group, a boryl-containing group, a phosphine-containing group, amino, a thio-containing group, a seleno-containing group, halide, or a nitro-containing group; a is 0 or 1; b is 0 or 1; and c is 0 or 1; provided that if X is C(O) then Y is not S.