Boronia coerulescens

These compounds are almost exclusively accumulated in aerial parts and leaves from genera of the Rutaceae such as Bosistoa, Boronia, and Melicope, and rarely in Euodia and Zanthox-ylum. There is a strong tendency towards prenylation at the 7-OH or 4 -OH group. From aerial parts of Boronia coerulescens, a derivative with 3,4 -(9-prenylation was also described (compound 130, Table 12.4). Similarly, only one C-6-(9-derivative was reported from the aerial parts of Melicope. Two 7-epoxy derivatives have already been listed in the previous survey. Combination with methylenedioxy substitution is less frequent, concerning a few sources of Rutaceae and Asteraceae only. Probably, these constituents are partly accumulated externally. 

Ahsan, M. et al., Novel O-prenylated flavonoids from two varieties of Boronia coerulescens, Phytochemistry, 37, 259, 1994. 

OH-7-OMe-4 -OPr C21H22O5 354 4 -0-Prenylsakuranetin Boronia coerulescens Rutaceae Aerial 80... 

From a chemosystematic point of view, it is interesting to note that prenylated flavonoids such as microfolione (56) have been found in a species of the family Ptaeroxylaceae, because the relationships of this family with other families were disputed in the past. Most taxonomists considered the Ptaeroxylaceae closely related to families in the order Rutales to which the Rutaceae and Meliaceae belong, whereas others considered it related to the Sapindaceae. Flavonoid chemistry supports a close relationship to the Rutaceae and Meliaceae, as iso-prenylated flavanones also occur in these families, e.g., 58 and 98 in Boronia coerulescens ssp. spinescens, the farnesyl-bearing 121 (Figure 15.3) in B. ramosa (Rutaceae)," and flowerine (59) and flowerone (60) in Azadirachta indica (Meliaceae). Microfolione is one of the few new flavanones for which the (2i )-configuration has been determined. 

Constit. of Boronia coerulescens (Rutaceae). Pale yellow oil. 

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