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Hydrangenol is an dihydroisocoumarin. It can found in Hydrangea macrophylla, as well as its 8-O-glucoside. (-)-hydrangenol 4'-O-glucoside and (+)-hydrangenol 4'-O-glucosidecan be found in Hydrangeae Dulcis Folium, the processed leaves of H. macrophylla var. thunbergii.
References
Effects of phyllodulcin, hydrangenol, and their 8-O-glucosides, and Thunberginols A and F from Hydrangea macrophylla SERINGE var. thunbergii MAKINO on passive cutaneous anaphylaxis reaction in rats. Matsuda H., Shimoda H., Yamahara J. and Yoshikawa M., Biological & pharmaceutical bulletin, 1999, vol. 22, no8, pp. 870-872, INIST1959604
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. Yoshikawa M, Uchida E, Chatani N, Kobayashi H, Naitoh Y, Okuno Y, Matsuda H, Yamahara J and Murakami N. Chem Pharm Bull (Tokyo). 1992 Dec;40(12), pp. 3352-3354, PMID1363465
Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside. Yoshikawa M, Matsuda H, Shimoda H, Shimada H, Harada E, Naitoh Y, Miki A, Yamahara J and Murakami N, Chem Pharm Bull (Tokyo). 1996 Aug;44(8), pp. 1440-1447, PMID8795265, INIST3226693