Tamosterone
sulfate |
14-Epitamosterone sulfate |
The tamosterones were isolated from an Oceanapiid sponge of a new genus collected in the Tamil
Channel (X. Fu, M. L. G. Ferreira, F. J. Schmitz & M. Kelly, Tamosterone sulfates: a C-14 epimeric
pair of polyhydroxylated sterols from a new Oceanapiid sponge genus. Journal of Organic Chemistry
64: 6706-6709, 1999). They are similar to brassinosteroids
as they are 3-oxygenated steroidal 22a,23a-diols, but are distinct from them by
presenting an oxygenation pattern of rings A, B and D not seen in natural brassinosteroids, as well as 14b
stereochemistry in 14-epitamosterone sulfate.
Asterasterol A |
Herbarulide |
Asterasterol A (S. De
Marino, E. Palagiano, F. Zollo,
L. Minale & M. Iorizzi,
A novel sulfated steroid with a 7-membered 5-oxalactone B-ring from an
Antarctic starfish of the family Asteriidae, Tetrahedron
53: 8625-8628, 1997) and herbarulide (K. Krohn, C. Biele, H.-J. Aust, S. Draeger & B. Schulz, Herbarulide,
a ketodivinyllactone steroid with an unprecedented
homo-6-oxaergostane skeleton from the endophytic
fungus Pleospora herbarum, Journal of Natural Products
62: 629-630, 1999) are the two known natural steroids, besides brassinosteroids, that present a lactone
function in ring B, but with opposite regiochemistry
of that found in brassinosteroids.