Astanga Hrudaya
तिक्तः कषायो मधुरस्तद्वदेव च शीतलाः। तिक्तः कटुः कषायश्च रूक्षा बद्धमलास्तथा॥३७॥
Cold Potency- Similarly Tikta (bitter), Kashaya (astringent) and Madhura (sweet) are cold in potency, each one more in their succeeding order. Ruksha- Tikta (bitter), Katu (pungent) and Kashaya (astringent) are dry and cause constipation (each one more so in their succeeding order)
english translation
tiktaH kaSAyo madhurastadvadeva ca zItalAH। tiktaH kaTuH kaSAyazca rUkSA baddhamalAstathA॥37॥
hk transliteration by Sanscript