Cucumaria conicospermium

Another example of an holothurin containing aglycon 51 with a (3-acetoxy group at C-16, Cucumarioside A2-5 (51c), was isolated from the sea cucumber Cucumaria conicospermium, collected in the Sea of Japan [71]. The same aglycone has been found earlier only in Cucumarioside Aq-1, isolated from Cucumaria japonica [72]. 

Fig. (31). Structures of non-holostane glycosides from the sea cucumbers Cucumaria koraiensis and Cucumaria conicospermium...

Six holothurins that lack a lactone function and have a shortened side chain have been isolated from sea cucumbers Cucumaria koraiensis, Cucumaria conicospermium and Duasmodactyla kurilensis. Cucumarioside Aj-2 (63a) [71] and Koreoside A (63b) [100], Fig. (31) contain a double bond while Cueumarioside Aa-3 (64a) [71], Isokoreoside A (64b) [71] and Kurilosides A (64c) and C (64d) [101], Fig. (32) contain a double bond. Kurilosides A (64c) and C (64d) contain a 16a-acetoxy group. 

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