A rhodamine based chemosensor for solvent dependent chromogenic sensing of cobalt (II) and copper (II) ions with good selectivity and sensitivity: Synthesis, filter paper test strip, DFT calculations and cytotoxicity.

A new chemosensor 1 was synthesized by reacting rhodamine B hydrazide and 2,3,4-trihydroxybenzaldehyde, which was then characterized by spectroscopic techniques and single crystal X-ray crystallography. Sensor 1 has the ability to sense Co2+/Cu2+ ions by "naked-eye" with an apparent colour change from colourless to pink in different solvent system, MeCN and DMF respectively. Furthermore, it can selectively detect Co2+/Cu2+ among wide range of different metal ions, and it exhibits low detection limit of 4.425 × 10-8 M and 1.398 × 10-7 M respectively. Binding mode of the two complexes were determined to be 1:1 stoichiometry for Co2+ complex and 1:2 stoichiometry for Cu2+ complex through Job's plot, IR spectroscopy, mass spectrometry and 1H NMR spectroscopy. Moreover, reversibility of the sensor 1 as copper (II) ion detector was determined by using EDTA and the results showed that sensor 1 can be reused for at least 6 cycles. Other than that, a low cost chemosensor test strips were fabricated for the convenient "naked-eye" detection of Co2+ and Cu2+ in pure aqueous media. The MTT assay was conducted in order to determine the cytotoxicity of sensor 1 towards human cell lines.

Macroline-Sarpagine Bisindole Alkaloids with Antiproliferative Activity from Alstonia penangiana.

A methanol extract of the stem bark of the Malayan Alstonia penangiana provided seven new bisindole alkaloids, comprising six macroline-sarpagine alkaloids (angustilongines E-K, 1-6) and one macroline-pleiocarpamine bisindole alkaloid (angustilongine L, 7). Analysis of the spectroscopic data (NMR and MS) of these compounds led to the proposed structures of these alkaloids. The macroline-sarpagine alkaloids (1-6) showed in vitro growth inhibitory activity against a panel of human cancer cell lines, inclusive of KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, HT-29, HCT 116, and A549 cells (IC50 values: 0.02-9.0 µM).

Antimelanogenesis and Anti-Inflammatory Activity of Selected Culinary-Medicinal Mushrooms.

Five culinary-medicinal mushrooms are commonly available in the Malaysian market: Agaricus bisporus (white and brown), Ganoderma lucidum, Hypsizygus marmoreus, Pleurotus floridanus, and P. pulmonarius. These species were selected for use in the current study, the aim of which was to investigate the antimelanogenesis and anti-inflammatory activity of these mushrooms in an attempt to evaluate their potential use in cosmeceuticals. Mushroom fruiting bodies were extracted with hot water, and the extracts were freeze-dried before testing. The antimelanogenesis activity of the extracts was determined by cell viability assay, measurement of intracellular melanin content, and cellular tyrosinase assay with B16F10 melanoma cells. The anti-inflammatory activity of the mushroom extracts was tested by measuring the levels of nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin-10 excreted by RAW264.7 macrophages. Brown A. bisporus reduced intracellular melanin content to the largest extent-up to 57.05 ± 3.90%-without a cytotoxic effect on B16F10 melanoma cells. This extract also reduced cellular tyrosinase activity to 17.93 ± 2.65%, performing better than kojic acid, the positive control. In parallel, the extract from brown A. bisporus, at the highest concentration tested, has appreciable anti-inflammatory activity through reductions of NO and TNF-α levels. The other 5 extracts showed moderate antimelanogenesis and anti-inflammatory activities. In summary, our findings show that A. bisporus (brown) extract has the potential to be used as an ingredient in whitening skincare products and to sooth the inflammatory response on the skin.