Tan-sûn phang-hiuⁿ khoân (單純芳香環; simple aromatic ring) sī chi̍t lūi iú-ki ê phang-hiuⁿ hoà-ha̍p-bu̍t. In tī hoà-ha̍k-siōng ê te̍k-sek sī lóng hâm-iú kiōng-ia̍h ê pêⁿ-bīn khoân-chōng thé-hē. Tián-hêng ê tan-sûn phang-hiuⁿ khoânū peⁿ-chìn kap ín-tó.