Prostanoids from

Clavulones I and II are members of an unusual family of marine prostanoids from the coral Clavularia viridis which are biosynthesiied by a cationic (i.e. non-radical, non-endoperoxide) pathway. The total synthesis of clavulones I and II was accomplished from cyclopentadiene as SM goal. 

Cyclooxygenases. Figure 1 Pathways for the formation of prostanoids from arachidonic acid. Arachidonic acid is converted by cyclooxygenase to endoperoxides, which are acted upon by various synthesases to form the prostanoids. Prostacyclin and thromboxane are relatively unstable and break down rapidly to form the inactive metabolites 6-oxo-PGF1a and thromboxane B2, respectively. 

Prostaglandin outflow. Oil was administered to weanling male rats fed ad libitum a semisynthetic diet supplemented with 10% by weight of primrose oil, replaced partly or completely (25, 50, 75, or 100%) by hydrogenated coconut oil for 8 weeks. The release of prostanoids from the mesenteric vasculature was significantly reduced in the animals on the diet with the oil replaced by coconut oil "k... 

Watanabe K, Sekine M, Iguchi K (2003) Isolation and Structures of New Halogenated Prostanoids from the Okinawan Soft Coral Clavularia viridis. J Nat Prod 66 1434... 

Dorta E, Diaz-Marrero A-R, Cueto M, D Croz L, Mate JL, Darias J (2004) Carijenone, a Novel Class of Bicyclic Prostanoid from the Eastern Pacific Octocoral Carijoa multiflora. Org Lett 6 2229... 

Extraction and purification of prostanoids from animal tissues was insufficient because the tissue levels are very low. 

Figure 6.2. The biosynthesis of prostanoids from arachidonic acid. Free arachidonic acid is converted to the unstable intermediates PGG, and PGH, by cyclooxygenase (COX) enzymes. PGH, is then converted to the five primary prostanoids by specific synthases.

Synthesis of prostanoids from arachidonic acid. Both activities reside in one enzyme. 

Formation of biologically active prostanoids from PGHj. 342... 

Korbecki, J., I. Baranowska-Bosiacka et al. 2013. The effect of reactive oxygen species on the synthesis of prostanoids from arachidonic acid. J Physiol Pharmacol 64(4) 409-421. 

FIGURE 11.13 Solution asymmetric synthesis of six-membered ring prostanoids. (From Pelegrm, J.A.L. and Janda, K.D., Solution- and soluble-polymer supported asymmetric synthesis of six-membered ring prostanoids, Chem. Eur. J., 6, 1917, 2000.)... 

Fig. 9.2 Biosynthetic pathways of the synthesis of prostanoids from arachidonic acid by isoenzymes COX-1 and COX-2 catalysis...

Kobayashi, M., T. Yasuzawa, M. Yoshihara, B.W. Son, Y. Kyogoku, and I. Kitagawa Absolute Stereostructures of Claviridenone-A, -B, -C, and -D, Four Prostanoids from the Okinawan Soft Coral Clavularia viridis. Chem. Pharm. Bull. (Japan) 31, 1440 (1983). 

Kikuchi, H., Y. Tsukitani, K. Iguchi, and Y. Yamada Clavulones, New Type of Prostanoids from the Stolonifer Clavularia viridis Quoy and Gaimard. Tetrahedron Lett. 23, 5171 (1982). 

Dorta, E., Diaz-Marrero, A.R., Cueto, M., D Croz, L, Mate, J.L., and Darias,). (2004a) Carijenone, a novel class of bicyclic prostanoid from the Eastern Pacific octocoral Carijoa multiflom. Org. Lett., 6, 2229-2232. 

Iwashima, M., Okamoto, K., Kormo, F., and Iguchi, K. (1999) New marine prostanoids from the Okinawan soft coral, Clavularia viridis. J. Nat Prod., 62, 352-354. 

Kobayashi, M., Yasuzawa, T, Yoshihara, M., Son, B.W., Kyogoku, Y, and Mtagawa, I. (1983a) Absolute structures of daviridenones A, B, C, D, four prostanoids from the Okinawan soft coral Clavularia viridis. Chem. Pharm. Bull, 31,1440-1443. 

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