Arecatannins are a class of condensed tannins in the sub-class procyanidins contained in the seeds of Areca catechu also called betel nut. The arecatannin-type natural products from Ceylonese cassia bark and Areca seed are examples polyphenols by both current definitions, and fit the distinct definition of a polymeric phenol as well.
^Screening of various plant extracts used in ayurvedic medicine for inhibitory effects on human immunodeficiency virus type 1 (HIV-1) protease. Ines Tomoco Kusumoto, Takeshi Nakabayashi1, Hiroaki Kida, Hirotsugu Miyashiro, Masao Hattori, Tsuneo Namba and Kunitada Shimotohno, Phytotherapy Research, Volume 9, Issue 3, May 1995, pp. 180–184, doi:10.1002/ptr.2650090305