Chemical constituents of Viscum coloratum (Kom.) Nakai and their cytotoxic activities.

A new diarylheptanoid, (1 R,2S,3S,5S)-2,3-dihydroxy-3',3''-dimethoxy-4'-de-O-methylcentrolobine (1) and a new bisabolane-type sesquiterpenoid, (1 R,7S)-1,12,13-trihydroxybisabola-3,10-diene (2), together with nineteen known compounds (3-21) were isolated from the EtOH extract of the stems and branches of Viscum coloratum (Kom.) Nakai. Their structures were elucidated by extensive analysis of 1 D and 2 D NMR spectra and from the HRESIMS. All the compounds were evaluated for their cytotoxic activity against eight human tumor cell lines.

Polyphenolic compounds from Malus hupehensis and their free radical scavenging effects.

One new 4-chromanone glycoside, 5-O-ß-d-glucopyranoside-4-chromanone (1), together with 21 known polyphenols, was isolated from the leaves of Malus hupehensis. Their structures were elucidated on the basis of extensive spectroscopic methods including NMR (1D and 2D), mass (ESIMS and HRESIMS), IR, and by comparison with the data reported in the literature. Some of the isolated compounds were screened for antioxidant activity. Compounds 18 and 14 exhibited significant antioxidant activities with SC50 values 2.73 and 2.91 µg/mL, respectively, while 17, 19, 11, 7, 20, 22, 12 and 13 exhibited moderate activities with SC50 values ranging from 5.24-11.86 µg/mL. The HPLC fingerprint profiles of the leaves and fruits extracts were also analysed, which showed that the constituents were almost the same in both the extracts except for the content of phlorizin which was present in higher amount in the leaves.