The new chlorinated peptides sintokamides A to E (1-5) have been isolated from specimens of the marine sponge Dysidea sp. collected in Indonesia. Their structures were elucidated by a combination of spectroscopic and single-crystal X-ray diffraction analyses. Sintokamide A (1) is an inhibitor of N-terminus transactivation of the androgen receptor in prostate cancer cells.

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Background:Fucoxanthin is a potential tumor cytotoxic compound. However, mechanisms underlying the activities are unclear.Aim:This in silico study aimed to predict the main mechanism of fucoxanthin; whether with its binding to p53 gene, CDK2, or tubulin.Materials and Methods:In silico was studied by using Autodock-Vina's algorithms. The mechanisms being analyzed by comparison of fucoxanthin and native ligands binding energies in p53 gene (1RV1), CDK2 (1AQ1), and three binding sites of tubulin (1JFF-paclitaxel, 1SA0-colchicine, and 1Z2B-vinblastine site).Results:Autodock-Vina's algorithms were valid, as re-docking the native ligands to their receptors showed a RSMD value less than 2 A with binding energies of -11.5 (1RV1), -14.4 (1AQ1), -15.4 (1JFF), -9.2 (1SA0), and -9.7 (1Z2B) kcal/mol. Docking of fucoxanthin to subjected receptors were -6.2 (1RV1), -9.3 (1AQ1), -8.1 (1JFF), -9.2 (1SA0), and -7.2 (1Z2B) kcal/mol. Virtual analysis of fucoxanthin and tubulin binding structure showed the carboxyl moiety in fucoxanthin make a hydrogen bound with 355Val (2.61 A) and 354Ala (2.79 A) at tubulin.Conclusion:The results showed that binding energy of fucoxanthin could only reach the same level as with colchicine ligand in tubulin. Therefore, it may predict that the most probable fucoxanthin main mechanism is to bind tubulin, which causes microtubules depolimerization and cell cycle arrest.

Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan, sitotoksisitas dan kandungan fukosantin ekstrak etil asetat beberapa jenis rumput laut coklat. Aktivitas antioksidan dianalisis dengan menggunakan metode 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) sedangkan aktivitas sitotoksik diuji dengan menggunakan metode {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide} (MTT). Kadar fukosantin dianalisis menggunakan metode Kromatografi Cair Kinerja Tinggi (KCKT). Enam jenis rumput laut coklat yaitu Sargassum ilicifolium, Sargassum binderi, Turbinaria decurrens, Turbinaria ornata, Padina australis dan Hormophysa triquetra telah dikoleksi dari pantai Binuangeun, Propinsi Banten. Ekstrak P. australis menunjukkan aktivitas antioksidan yang paling tinggi diiikuti oleh H. triquetra dan T. decurrens. Hasil uji memperlihatkan bahwa ekstrak T. decurrens menghambat pertumbuhan sel HeLa dan T47D sedangkan H. triquetra hanya menghambat pertumbuhan sel T47D. Kadar fukosantin tertinggi dihasilkan oleh ekstrak H. triquetra sebesar 88,5 mg/g diikuti oleh T. decurrens, dan P. australis, berturut-turut sebesar 86,9 mg/g, dan 77,8 mg/g. Di lain sisi, kandungan fukosantin ekstrak S. ilicifolium, T. ornata, dan S. binderi relatif rendah (<20 ppm).

Crosslinked PEO hydrogel containing chitosan for wound dressing has been prepared by gamma radiation technique. Chitosan solutions with different concentration (0.5-2% w/v) have been blended with 5% aqueous solution of PEO and irradiated at the doses 20-40 kGy by gamma rays. The copolymers were characterized by Fourier transform infra red spectroscopy and their physico-chemical properties of hydrogels were evaluated in terms of gel fraction, swelling ratio, elongation at break and antimicrobial activities. It was found that under maximum condition of incorporation 1% chitosan with irradiation dose of 20 kGy, PEO-chitosan hydrogels with high gel fraction (85%), swelling ratio (10 g/g) and elongation at break (145%) were obtained. The examination of the microbe penetration shows that the prepared hydrogels can be considered as a good barrier against microbes. Thus, PEO-chitosan hydrogel showed satisfactory properties for use as a wound dressing.