Enzymatic catalysis of the Diels-Alder reaction in the biosynthesis of natural products.

Folk herbal medicines from tribal area of Rajasthan, India

Effect of Helicteres isora root extracts on glucose tolerance in glucose-induced hyperglycemic rats

Chloropestolide A, an antitumor metabolite with an unprecedented spiroketal skeleton from Pestalotiopsis fici.

Activity-guided fractionation of Theobroma grandiflorum (“cupuacu”) seeds resulted in the identification of two new sulfated flavonoid glycosides, theograndins I (1) and II (2). In addition, nine k...

New bioactive polyphenols from Theobroma grandiflorum ("cupuaçu").

During a chemical study of Indonesian medicinal plants, we examined the constituents of fruits of Helicteres isora L. (Sterculiaceae), one of the famous Jamu medicines. From a water extract of the fruits, we isolated three new neolignans, helisterculins A (1) and B (2) and helisorin (3), and elucidated their structures by spectral analyses. Helisterculins A (1) and B (2) are (7.5′,8.2′)-neolignans with a bicyclo[2.2.2]octene C-framework, while helisorin (3) is a (6.4′,7.5′,8.2′)-neolignan with a very rare 4,4a,9,9a-tetrahydro-3,9-methano-3H-fluorene C-framework. The natural product with the latter C-framework has no literature precedent. The neolignans 1 – 3 showed weak inhibitory activity against reverse transcriptase from avian myeloblastosis virus.

Helisterculins A and B, Two New (7.5′,8.2′)-Neolignans, and Helisorin, the First (6.4′,7.5′,8.2′)-Neolignan, from the Indonesian Medicinal PlantHelicteres isora

Yukiko Kawashima

Papers

Helisterculins A and B, Two New (7.5′,8.2′)-Neolignans, and Helisorin, the First (6.4′,7.5′,8.2′)-Neolignan, from the Indonesian Medicinal PlantHelicteres isora