Isolation, structure elucidation, and cytotoxic evaluation of furanonaphthoquinones from in vitro plantlets and cultures of Streptocarpus dunnii.

Two new furanonaphthoquinones, (3R)-7-methoxy-α-dunnione (5) and (3R)-6-hydroxy-7-methoxy-α-dunnione (6), along with the known (3R)-dunnione (1), (3R)-α-dunnione (2), (3R)-7-hydroxy-α-dunnione (3), and 1-hydroxy-2-methylanthraquinone (4), were isolated from in vitro cultures of Streptocarpus dunnii. The structures of compounds 5 and 6 were established by spectroscopic means. This is the first report of hydroxylated furanonaphthoquinones in a Streptocarpus species.

Inhibition of LFA-1 mediated T-cell motility by naphthoquinones.

An in vitro T-cell migration assay has been established that can be used to study the effects of compounds on the development of T-cell polarisation with HuT-78 T lymphocytes. This assay indicates the ability of compounds tested to inhibit the inflammatory response by decreasing LFA-1-mediated T-cell motility. The effect of a series of naturally occurring quinone isolates on motility has been evaluated in this assay.