Minor and trace sterols from marine invertebrates 29. (22E)-ergosta-5,22,25-trien-3 beta-ol and (22E,24R)-24,26-dimethylcholesta-5,22,25(27)-trien-3 beta-ol. Two new marine sterols from the sponge Pseudaxinella lunacharta

A new bioactive steroidal ketone from the South China Sea sponge Xestospongia testudinaria

A new steroidal ketone (1), with an ergosta-22,25-diene side chain, was obtained from the South China Sea marine sponge Xestospongia testudinaria. The structure of 1 was determined on the basis of detailed spectroscopic analysis and by comparison with literature. Compound 1 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC50 value of 4.27 ± 0.55 μM, which is comparable with the positive control oleanolic acid (IC50 = 2.63 ± 0.22 μM).

In Vitro Antiviral Activity of Marine Sponges Collected Off Brazilian Coast

This paper describes the in vitro antiviral evaluation of 27 different marine sponges (Porifera) collected off Brazilian coastline in the search for novel drug leads. With these sponges aqueous and organic extracts were prepared and tested for anti-herpetic (HSV-1, KOS strain), anti-adenovirus (human AdV serotype 5) and anti-rotavirus (simian RV SA11) activities. The evaluation of the cytotoxicity and potential antiviral activity of these extracts were performed by using MTT assay. Results were expressed as 50% cytotoxicity (CC50) and 50% effective (EC50) concentrations, respectively, in order to calculate the selectivity indices (SI=CC50/EC50) of each extract. From the 40 sponge extracts tested, 17 extracts showed antiviral action in different degrees. The results concerning the antiviral activity were obtained by using three different strategies: (1) simultaneous assay, when sponge extracts were added to the cells at the same time of the viruses; (2) pre treatment assay, when sponge extracts were added to the cells 15 h prior to the viruses infection; and (3) post treatment assay, when the viruses were added to the cells and remained during 2 h prior to the addition of sponge extracts. The antiviral assays with HSV-1/KOS and AdV-5 showed more promising results when the pre treatment test was employed. In relation to the RV-SA11 virus, only the simultaneous assay showed antiviral activity. The extracts presenting the most promising results were the aqueous extracts of Cliona sp., Agelas sp.2, Tethya sp., Axinella aff corrugata, Polymastia janeirensis and Protosuberites sp., and these extracts deserve special attention in further studies.