Abstract
Six new withanolide-type steroids, designated cilistols v, t, i, j, y and w (1-6, respectively), were obtained from the leaves of Solanum cilistum. Their respective structures were characterized by spectroscopic means as follows: Cilistol v (1) was (22R, 24Z)-1α, 3β, 22, 26-tetrahydroxyergost-5, 24-diene 26-O-β-D-glucopyranoside, which is regarded as the precursor of other withanolide-type steroids included in this title plant. Cilistol t (2) was (22R, 24S, 25R, 26S)-24, 25;22, 26-diepoxy-1α, 3β, 26-trihydroxyergost-5-ene 26-O-β-D-glucopyranoside, and cilistols j (3) and i (4) corresponded to the substances probably formed by the cleavage of the epoxy ring at C-24 and 25 of 2. Cilistol y (5) was 3-O-sulphonyl (22R, 24S, 25R, 26R)-1-oxo-24, 25; 22, 26-diepoxy-3β, 17α, 26-trihydroxyergost-5-ene 26-O-β-D-glucopyranoside, and cilistol w (6) corresponded to the substance obtained by the fission of the epoxy ring at C-24 and 25 of 5. The occurrence of these withanolide type steroids from Solanum genera is rare and worthy of note.
