Baccharis genus flavonoids from

To date more than 100 species from the large genus Baccharis have been investigated chemically. The most widespread compounds are clerodane diterpene derivatives, but labdane derivatives have also been isolated. Furthermore, typical acetylenic compounds, baccharis oxide, a unique triterpene, and derivatives of hydroxyacetophenone are present, although it is mainly other biologically active constituents, e.g. flavonoids, sesquiterpenes and essential oils that have been reported in the last years. The constituents of Baccharis species compiled from different sources are presented below. 

The most widespread flavonoids reported in the Baccharis genus are flavones, but flavonols and flavanones have also been isolated. For example, Kupchan and Baverschmidt [74] reported the isolation and identification of two methylated flavonols, 3,4 -dimethoxy-3 ,5,7-trihydroxyflavone, Fig. (43) and centaureidin, Fig. (44) from B. sarolhroides. 

Tortoriello and Aguilar-Santamaria [120] investigated in detail the spasmolytic mechanisms of action of one of these plants, B. serraefolia. The results suggest that the extract does not interact with classical receptors and its effects, at least that produced on smooth muscle, may be due to a probable interference with calcium influx and/or calcium release from an intracellular store. Different chemical compounds, such as clerodane diterpenes and flavonoids, which are typical constituents from the Baccharis genus, have been considered as the active principles of many spasmolytic drugs. A bioassay-monitored fractionation of an extract from B. genistelloides yielded a mixture that blocked the calcium-induced contractions of KCl-depolarized rat portal vein preparations [121], Pharmacological tests of two pure compounds isolated from the mixture revealed a dilactonic clerodane-diterpene, Fig. (70) as the active compound. 

---