Chemical and Pharmacological Investigations of Metaxya rostrata

Abstract

In a bioassay-guided approach the chemical composition of rhizomes of Metaxya rostrata (Kunth C. Presl) was studied for the first time. Investigations of the cytotoxicity of extracts and fractions on SW480 colorectal carcinoma cells resulted in the isolation of two polyphenols Ð cinnamtannin B-1 and aesculitannin B. The structures of the compounds were elucidated by different NMR experiments. Additionally, sugars, common sterols, such as sitosterol, stigmasterol and campesterol, as well as chlorogenic acid and caffeic acid were identified in Metaxya rostrata.

2-Deprenyl-Rheediaxanthone B Isolated from Metaxya rostrata Induces Active Cell Death in Colorectal Tumor Cells

“…The polyphenols cinnamtannin B-1 and aesculitannin B have been isolated in a previous study. With an IC 50 of about 11 µM XB is much more effective in SW480 cells than the polyphenols, that induced cell death with an IC 50 of about 50 µM [20]. Viability of other colon carcinoma cell lines was similarly reduced by XB with IC 50 concentration ranging from 10–23 µM.…”

“…The plant is common in the rain forests of Central and South America and used in ethnic medicine for the treatment of intestinal ulcers and tumours [20], which made it a promising source of cytotoxic lead compounds. XB is not the only bioactive compound in Metaxya rostrata .…”

Two Unusual Methylidenecyclopropane Glucosides from Metaxya rostrata C.Presl

“…The fractions of different polarity (AcOEt fraction (0.75 g), BuOH fraction (26.35 g), and MeOHfraction (18.7 g)) were subjected to vacuum liquid chromatography (VLC) on silica (15 – 40 μm, Merck ) with AcOEt/MeOH/H 2 O mixtures of increasing polarity as mobile phases. All obtained fractions after these three fractionation steps were pooled according to their composition to 15 combined fractions [1]. Fr.…”

“…For the treatment of these diseases, a suspension of the dried rhizome of Metaxya rostrata in water is applied orally [1]. As tropical plants are a rich and promising source for new cytotoxic compounds [2], and no data were available on the chemical composition of this plant, the rhizomes of Metaxya rostrata were studied phytochemically.…”

“…In our previous investigation, an aqueous extract of the rhizomes was fractionated. Within this earlier study, two cytotoxic proanthocyanidins (cinnamtannin B-1 and aesculitannin B), common sterols, and sugars had been isolated [1]. Further separation of other fractions from the aqueous extract which did not show significant cytotoxicity should give a more detailed insight into the chemical composition of this plant.…”