2.4.9. Clade Asterids

Plants in this clade yield antimicrobial triterpenes (Table S2).

In the order Ericales, the ethanol extract of the bark of the true mangrove tree *Diospyros littorea* (R. Br.) Kosterm. (Ebenaceae) developed halos with *Streptococcus* sp., *S. aureus*, *Aeromonas hydrophila*, and *Vibrio parahaemolyticus* [62].

Antimicrobial principles in the Lecythidaceae are mainly triterpene saponins that are soluble in polar organic and aqueous extracts, explaining why plants in the genus *Barringtonia* J.R. Forst. & G. Forst. are antibacterial and antifungal. The methanol extract of leaves of *Barringtonia acutangula* (L.) Gaertn. hindered *C. albicans* and *Candida tropicalis* with the MIC values of 31.2 and 62.5 μg/mL, respectively [202,203]. Other examples include the methanol extract of *Barringtonia asiatica* (L.) Kurz [204] or *Barringtonia racemosa* (L.) Spreng [205,206]. Other antimicrobial principles are oleanane triterpenes such as germanicol caffeoyl ester (**61**), camelliagenone (**62**), and germanicol (**63**) in *B. asiatica* (Table S2) [207] or lupeol (**40**) (Table S2) [208]. These are mainly lipophilic, where activities in non-polar extracts as exemplified with the petroleum ether extract of the stem bark of *B. asiatica* that strongly restrained *B. subtilis* with the MIC value of 25 μg/mL, respectively [209]. Other lipophilic to mid-polar principles in *B. racemosa* are neo-clerodane diterpenes such as nasimalun A (**64**) [204,208,210]. The aqueous extract suppressed HSV-1 (IC50: 23 μg/mL) [211].

The ethanol extract of the bark (500 μg/disc) of the true mangrove tree *Aegiceras corniculatum* (L.) Blanco (Aegicerataceae) developed a halo with a broad spectrum of bacteria [28], while the hexane extract of leaves inhibited the growth of *Mycobacterium tuberculosis* (H37Rv) with the MIC value of 50 μg/mL [212]. The oleanane triterpene acornine 2 (**65**) isolated from the bark hindered yeasts and filamentous fungi (Table S2) [212]. The ethanol extract of fruits inhibited NDV and SFV [130].
