Synthesis of novel 5,6-dehydrokawain analogs as osteogenic inducers and their action mechanisms

Phytochemical and pharmacological properties of the genus Alpinia from 2016 to 2023

Covering 2016 up to the end of 2023Alpinia is the largest genus of flowering plants in the ginger family, Zingiberaceae, and comprises about 500 species. Many Alpinia are commonly cultivated ornamental plants, and some are used as spices or traditional medicine to treat inflammation, hyperlipidemia, and cancers. However, only a few comprehensive reviews have been published on the phytochemistry and pharmacology of this genus, and the latest review was published in 2017. In this review, we provide an extensive coverage of the studies on Alpinia species reported from 2016 through 2023, including newly isolated compounds and potential biological effects. The present review article shows that Alpinia species have a wide spectrum of pharmacological activities, most due to the activities of diarylheptanoids, terpenoids, flavonoids, and phenolics.

Synthetic Kavalactone Analogues with Increased Potency and Selective Anthelmintic Activity against Larvae of Haemonchus contortus In Vitro

Kava extract, an aqueous rhizome emulsion of the plant Piper methysticum, has been used for centuries by Pacific Islanders as a ceremonial beverage, and has been sold as an anxiolytic agent for some decades. Kavalactones are a major constituent of kava extract. In a previous investigation, we had identified three kavalactones that inhibit larval development of Haemonchus contortus in an in vitro-bioassay. In the present study, we synthesized two kavalactones, desmethoxyyangonin and yangonin, as well as 17 analogues thereof, and evaluated their anthelmintic activities using the same bioassay as employed previously. Structure activity relationship (SAR) studies showed that a 4-substituent on the pendant aryl ring was required for activity. In particular, compounds with 4-trifluoromethoxy, 4-difluoromethoxy, 4-phenoxy, and 4-N-morpholine substitutions had anthelmintic activities (IC₅₀ values in the range of 1.9 to 8.9 µM) that were greater than either of the parent natural products-desmethoxyyangonin (IC₅₀ of 37.1 µM) and yangonin (IC₅₀ of 15.0 µM). The synthesized analogues did not exhibit toxicity on HepG2 human hepatoma cells in vitro at concentrations of up to 40 µM. These findings confirm the previously-identified kavalactone scaffold as a promising chemotype for new anthelmintics and provide a basis for a detailed SAR investigation focused on developing a novel anthelmintic agent.