The genus Chloranthus (Chloranthaceae) consists of 13 species and 5 varieties, which are mainly distributed in the eastern region of Asia [1]. Many plants in this genus have long been used as traditional medicinal herbs for the treatment of fractures, pulmonary tuberculosis, and neurasthenia [2]. To date, many chemical constituents have been isolated from the genus Chloranthus, while amides and their derivatives are rarely present in the genus, with only approximately seven analogs isolated from Chloranthus [3], [4], [5], [6], [7], [8], [9]. Chloranthus henryi var. hupehensis (Chloranthaceae) is a variant of C. henryi of this genus that grows mainly in Shaanxi, Hubei, and Gansu Provinces of China [1]. Phytochemical studies have shown that the main chemical constituents of the Chloranthus genus are sesquiterpenoids [10], [11]. Most of these compounds have good anti-inflammatory properties [10], [11]. Our previous phytochemical investigation of this plant afforded structurally diverse sesquiterpenoids, some of which also showed significant anti-inflammatory activities [6], [8], [9], [12], [13].

In the course of our continuous study on the new type of bioactive constituents of this genus, eleven new amides, including five amide dimers, four lignanamides and two amide monomers, were isolated (Fig. 1). Compounds 1–3 possess a unique cyclobutene skeleton by an unprecedented [2 + 2] cycloaddition of two dissimilar cinnamic acid amides. Compounds 4–5 are rare lignanamides formed by the tetrohydrofuran lignan with an amide moiety. Herein, we describe the isolation, structure elucidation, and plausible biogenetic pathways of eleven new compounds, as well as the anti-inflammatory activities of these compounds.