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Six new spiranoid withanolides, (20R,22R,23S)-5alpha-chloro-6beta,12beta,17beta,22-tetrahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (2), (20R,22R,23S)-5beta,6beta-epoxy-12beta,17beta,22-trihydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (3), (20R,22R,23S)-5beta,6beta-epoxy-4beta,12beta,17beta,22-tetrahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (4), (20R,22R,23S)-5alpha,6beta,12beta,17beta,22-pentahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (5), (20R,22R,23S)-6beta,12beta,17beta,22-tetrahydroxy-5alpha-methoxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (6), and (20R,22R,23S)-6beta,12beta,17beta,22-tetrahydroxy-2alpha,5alpha-epidioxy-1-oxo-12,23-cycloergosta-3,24-dien-26,23-olide (7), were isolated from the leaves of Jaborosa odonelliana. Compounds 2-7 were characterized by a combination of spectroscopic methods (1D and 2D NMR, MS) and molecular modeling.

Eight new withanolides were isolated from the aerial parts of Vassobia lorentzii and characterized by spectroscopic methods and with the aid of molecular modeling. The compounds were identified as (17S,20R,22R)-5beta,6beta:18,20-diepoxy-18-hydro xy-1-oxowitha-2,5, 24-trienolide (1); (17S,20R,22R)-18,20-epoxy-4beta, 18-dihydroxy-1-oxowitha-2,5,24-trienolide (2); (17S,18R,20R, 22R)-4beta-hydroxy-18,20-epoxy-18-methoxy-1-oxowitha-2,5, 24-trienolide (3); (17S,18S,20R,22R)-4beta-hydroxy-18, 20-epoxy-18-methoxy-1-oxowitha-2,5,24-trienolide (4); (17S,20R, 22R)-4beta-hydroxy-18,20-epoxy-1,18-dioxowitha-2,5,24-tri enolide (5); (17S,18R,20R,22R)-18,20-epoxy-18-methoxy-1,4-dioxowitha++ +-2,5, 24-trienolide (6); (17S,18S,20R,22R)-18,20-epoxy-18-methoxy-1, 4-dioxowitha-2,5,24-trienolide (7); and (17S,20R,22R)-5beta, 6beta-epoxy-4beta,18,20-trihydroxy-1-oxowitha-2,24-die nolide (8). Compounds 1 and 2 were obtained as epimeric mixtures at C-18.