Taufiq Yun Hin Yap

Acid fuchsin-interleaved Mg–Al-layered double hydroxide for the formation of an organic–inorganic hybrid nanocomposite

Abstract Layered organic–inorganic hybrid nanocomposite, containing an organic dye in an inorganic interlayer was prepared using acid fuchsin (AF) as a guest in Mg–Al layered double hydroxide inorganic host by a self-assembly technique, with the Mg–Al ratio in the mother liquor of 4 and pH=7.5. Powder X-ray diffractogram shows that the basal spacing of the Mg–Al layered double hydroxide with nitrate as the intergallery anion expanded from 8.9 to 17.1 A to accommodate the AF anion, for the formation of the Mg–Al layered double hydroxide-AF layered organic–inorganic hybrid nanocomposite (MAAF). Formation of such a material is useful for example for coating or controlled release purposes of dye for slow dyeing process.

A new xanthone from Garcinia nitida

A detailed chemical study on the stem bark of Garcinia nitida has led to the isolation of five xanthones. They are 1,6-dihydroxy-5-methoxy-6,6-dimethylpyrano[2′,3′:2,3]-xanthone (1), inophyllin B (2), osajaxanthone (3), 3-isomangostin (4) and rubraxanthone (5). The structures of these compounds were established using mainly 1-D and 2-D NMR spectroscopy (1H, 13C, DEPT, COSY, HMBC and HMQC) while molecular masses were determined via MS techniques; 1 is a new compound.