sarcophytol-a and sarcophine

The soft coral Sarcophyton glaucum is a rich resource of several bioactive cembranoids. Sarcophytol A (1) and sarcophine (2) are cembranoid diterpenes reported from this soft coral and extensively investigated for their cancer chemopreventive properties. This study aimed at investigating the antimetastatic potential of the major cembranoids, sarcophine (2) and 2-epi-16-deoxysarcophine (3), from the Red Sea soft coral S. glaucum. Biocatalytic transformation of 3 using Rhizopus stolonifer ATCC 6227a and Absidia spinosa ATCC 6648 afforded four new metabolites, 5-7 and 9, along with the known 9alpha-hydroxysarcophine (8). Sarcophine, 2-epi-16-deoxysarcophine, and metabolites 5-9 revealed significant antimetastatic activity against the highly metastatic mouse melanoma cell line (B16B15b). Cembranoids demonstrate a great potential for further development as antimetastatic agents.

Topics: 4-Butyrolactone; Animals; Anthozoa; Anticarcinogenic Agents; Diterpenes; Drug Screening Assays, Antitumor; Marine Biology; Melanoma; Mice; Molecular Structure; Tumor Cells, Cultured; Wound Healing

Cembranoids are natural diterpenes with 14-membered macrocyclic rings. The simplest natural cembranoid, (+)-cembrene, was isolated from pine oleoresin. Sarcophytols A and B are known cembranoids that inhibit tumor promotion. Sarcophine is a related cembranoid isolated from the Red Sea soft coral Sarcophyton glaucum. Sarcophine and its bioconversion products and semisynthetic derivatives are reported to possess cancer chemopreventive activity. Oxymercuration-demercuration of sarcophine using Hg(OAc)2 and NaBH4 afforded four new rearranged and hydroxylated products. Bromination of sarcophine with N-bromosuccinimide (NBS) furnished two new brominated and rearranged products. Reaction with iodine gave the known iso-sarcophinone and (+)-sarcophytoxin B. Structure elucidation was based on a combination of transition state modeling, molecular dynamics, mechanistic considerations, and 2D NMR data. The antiproliferative activity of the new products is also reported.

Topics: 4-Butyrolactone; Animals; Anthozoa; Antineoplastic Agents; Crystallography, X-Ray; Diterpenes; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Hydrocarbons, Brominated; Indian Ocean; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Stereoisomerism; Tumor Cells, Cultured

The natural cembranolide sarcophine (3) and its lactone ring-opened analogue (10) were oxidized using selenium dioxide under different reaction temperatures to prepare hydroxylated derivatives. Nine new compounds were obtained, six of them targeted hydroxylated derivatives. The determination of regio- and stereochemistry as well as the mechanistic considerations on the selectivity observed in these reactions are discussed on the basis of 2D NMR and molecular modeling. In preliminary in vitro tests on inhibition of EBV-EA activation, compounds 10 and 12-15 have shown higher activity than the known chemopreventive agent sarcophytol A.

Topics: 4-Butyrolactone; Animals; Anthozoa; Anticarcinogenic Agents; Antigens, Viral; Chemoprevention; Dose-Response Relationship, Drug; Egypt; Hydroxylation; Indian Ocean; Models, Molecular; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Selenium Compounds; Selenium Oxides; Stereoisomerism; Structure-Activity Relationship