Provided are a polypeptide having excellent 4-aminobenzoic acid hydroxylation activity and a method for using the same. The present invention provides a polypeptide having 4-aminobenzoic acid hydroxylation activity, consisting of the amino acid sequence represented by SEQ ID NO: 2 or an amino acid sequence having at least 47% identity thereto, and having an amino acid residue at position 47 of the amino acid sequence represented by SEQ ID NO: 2 or a position corresponding thereto being leucine.

Provided are a polypeptide having excellent 4-aminobenzoic acid hydroxylation activity and a method for using the same. The present invention provides a polypeptide having 4-aminobenzoic acid hydroxylation activity, consisting of the amino acid sequence represented by SEQ ID NO: 2 or an amino acid sequence having at least 47% identity thereto, and having an amino acid residue at position 47 of the amino acid sequence represented by SEQ ID NO: 2 or a position corresponding thereto being leucine.

The present disclosure relates to compounds of the general formula (I): wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, and R.sub.7 may be chosen from different substituents; n is 0, 1, or 2; and X is a hydroxymethyl or a carboxylic acid or a derivative thereof, such as a carboxylate, such as a carboxylic ester, a glyceride, an anhydride, a phospholipid, a carboxamide, a phospholipid, or a prodrug thereof; or a pharmaceutically acceptable salt, solvate, solvate of such salt or a prodrug thereof. The present disclosure also relates to pharmaceutical compositions and lipid compositions comprising at least one compound according to the present disclosure, and to such compounds for use as medicaments or for use in therapy, in particular for the treatment of diseases related to metabolic diseases and liver diseases, such as non-alcoholic fatty liver disease and cholestasis diseases.

A method for synthesizing 5,8-diamino-3,4-dihydro-2H-1-naphthalenone (Compound I), which method comprises: subjecting 2,5-diprotected aminophenylbutyric acid to the Friedel-Crafts reaction for ring closure, and then removing a protecting group on the amino group to obtain Compound I.

A method for synthesizing 5,8-diamino-3,4-dihydro-2H-1-naphthalenone (Compound I), which method comprises: subjecting 2,5-diprotected aminophenylbutyric acid to the Friedel-Crafts reaction for ring closure, and then removing a protecting group on the amino group to obtain Compound I.

The present disclosure relates to compounds of the general formula (I): ##STR00001##
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, and R.sub.7 may be chosen from different substituents; n is 0, 1, or 2; and X is a hydroxymethyl or a carboxylic acid or a derivative thereof, such as a carboxylate, such as a carboxylic ester, a glyceride, an anhydride, a phospholipid, a carboxamide, a phospholipid, or a prodrug thereof; or a pharmaceutically acceptable salt, solvate, solvate of such salt or a prodrug thereof. The present disclosure also relates to pharmaceutical compositions and lipid compositions comprising at least one compound according to the present disclosure, and to such compounds for use as medicaments or for use in therapy, in particular for the treatment of diseases related to metabolic diseases and liver diseases, such as non-alcoholic fatty liver disease and cholestasis diseases.