Hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii as a new type of anti-diabetic compound. Hailong Zhang, Hisashi Matsuda, Chihiro Yamashita, Seikou Nakamura and Masayuki Yoshikawa, European Journal of Pharmacology, Volume 606, Issues 1–3, 15 March 2009, Pages 255–261, doi:10.1016/j.ejphar.2009.01.005
Yoshikawa, M.; Uchida, E.; Chatani, N.; Kobayashi, H.; Naitoh, Y.; Okuno, Y.; Matsuda, H.; Yamahara, J. et al. (1992). "Thunberginols C, D, and E, New Antiallergic and Antimicrobial Dihydroisocoumarins, and Thunberginol G 3'-O-Glucoside and (-)-Hydrangenol 4'-O-Glucoside, New Dihydroisocoumarin Glycosides, from Hydrangeae Dulcis Folium" (pdf). Chemical and Pharmaceutical Bulletin 40 (12): 3352–3354. doi:10.1248/cpb.40.3352. PMID 1363465.