Sterol Ring System Oxidation Pattern in Marine Sponges

摘要: The marine sponges (Porifera) are a unique group of sedentary organisms from which several novel natural products reported, many have useful biological activities. In producing unusual sterols, they occupy preeminent position among the various groups organisms. polar sterols reported as at end year 2002 number about 250; their ring structure changing hundred times. oxidation pattern in sterol system, point view biogenesis seems to be mainly four types. Each sponge species is able produce fitting into one main biogenetic pathways viz., (i) 3β-hydroxy-Δ5-sterol pathway, (ii) 3β-hydroxy-Δ7-sterol (iii) 3β-hydroxy-Δ5,7-sterol and (iv) 3α-hydroxy pathway.