Lpa receptor agonists and antagonists and methods of use

A method for treating diarrhea in a human or animal subject, the method comprising administering to the subject a pharmaceutical composition comprising a compound of formula (I)

• wherein,
• X1 is R1—Y1-A-;
• X2 is —Z1—P(S)(OH)2;
• X3 is hydrogen;
• A is a direct link, (CH2)k with k being an integer from 1-30, or O;
• Y1 is (CH2)l with l being an integer from 1-30;
• Z1 is —O—;
• Q1 and Q2 are independently selected from the group consisting of H2, ═NR4, ═O, or —NR5R6;
• R1 is independently a straight or branched-chain C2 to C30 alkenyl, an aromatic or heteroaromatic ring with or without mono-, di-, or tri-substitutions of the ring, an acyl group substituted by a C1 to C30 alkyl oran aromatic or heteroaromatic ring, an arylalkyl including straight or branched-chain C1 to C30 alkyl, an aryloxyalkyl including straight or branched-chain C1 to C30 alkyl,
• and
• R2, R3, R4, R5, R6, R7, and R8 are independently hydrogen, a straight or branched-chain C1 to C30 alkyl, a straight or branched-chain C2 to C30 alkenyl, an aromatic or heteroaromatic ring with or without mono-, di-, or tri-substitutions of the ring, an acyl including a C1 to C30 alkyl or aromatic or heteroaromatic ring, an arylalkyl including straight or branched-chain C1 to C30 alkyl, or an aryloxyalkyl including straight or branched-chain C1 to C30 alkyl.