ISSN 1880-7682 Volume 13, No. 4 August 2015 ISME/GLOMIS Electronic Journal (ISSN 1880-7682) is published by International Society for Mangrove Ecosystems (ISME). Available on-line at http://www.glomis.com. Headquarters: c/o Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0129 Japan. 12 ISME/GLOMIS Electronic Journal An electronic journal dedicated to enhance public awareness on the importance of mangrove ecosystems ____________________________________________________________________________________ Botany, uses, chemistry and bioactivities of mangrove plants I: Rhizophora stylosa Mami Kainuma 1 , Mio Kezuka 1 , Tomomi Inoue 2 , Eric W.C. Chan 3 , Joseph Tangah 4 , Shigeyuki Baba 1 & Hung Tuck Chan 1 1 Secretariat, International Society for Mangrove Ecosystems, c/o Faculty of Agriculture, University of the Ryukyus, Okinawa, 903-0129 Japan (e-mail: isme@mangrove.or.jp) 2 Centre for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba 305-0053, Japan 3 Faculty of Applied Sciences, UCSI University, Cheras 56000, Kuala Lumpur, Malaysia 4 Forest Research Centre, Sabah Forestry Department, Sandakan 90009, Sabah, Malaysia Introduction Mangrove species of Rhizophora (R. apiculata, R. mucronata and R. mangle) are endowed with chemical constituents of terpenoids, flavonoids, phenolic acids and steroids (Wu et al., 2008; Nebula et al., 2013). They possess antioxidant (Bunyapraphatsara et al., 2003; Sánchez, et al., 2006; Rahim et al., 2008; Ravikumar & Gnanadesigan, 2012), antibacterial (Melchor et al., 2001; Howlader et al., 2013; Annapoorani et al., 2013), anti- viral (Premanathan et al., 1999), anti-ulcer (Perera, et al., 2001; de Armas, et al., 2005; Berenguer et al., 2006; de-Faria, et al., 2012), analgesic (Rohini & Das, 2009; Howlader, et al., 2013), anti-inflammatory (Rohini & Das, 2009, 2010; Prabhu et al., 2012), cytotoxic (Prabhu et al., 2012; Howlader, et al., 2013), anti-diabetic (Ramanathan et al., 2008; Alikunhi et al., 2012), diuretic (Howlader, et al., 2013), hepato-protective (Ravikumar & Gnanadesigan, 2012.), anti-diarrheal (Rohini & Das, 2010), and wound healing (Fernandez et al., 2002; de Armas et al., 2005) properties. Metabolites and bioactivities of Rhizophoraceae including Rhizophora stylosa have only been reviewed by Nebula et al. (2013). In a review of natural products from mangrove flora by Wu et al. (2008), information on R. apiculata and R. mucronata was presented but not on R. stylosa. In this note, the chemistry and bioactivities of R. stylosa, which are lesser known, are updated with some description of its botany and uses. Results of a DNA analysis of R. stylosa from Kiribati are included. Botany and Uses Rhizophora stylosa Griff. occurs on sand flats or rocky promontories fronting the sea (Chan, 1996; Chan & Wong, 2009; Nilus et al., 2010; Ng & Chan, 2012a). Under such exposed conditions, trees have gnarled growth with no clear bole and extensive prop roots looping outwards (Figure 1, left). In young trees, the bark is reddish brown while in old trees, the bark is greyish black and fissured. The leaf blade is broadly elliptic, apex with prominent mucronate spike, pale green midrib and clear black dots at the under surface. (Figure 1, right). Inflorescences are branched 2−4 times with 4−8 cream-colored buds borne on elongated peduncle. Flowers have four white petals with woolly margins and elongated style of 4−5 mm. Fruits are ovate and brown when ripe. Hypocotyls are cylindrical, warty with pointed tip, 30 cm in length, and collars are bulbous and yellow in colour.