Hiroyuki Yamazaki , Defny S. Wewengkang , Teruaki Nishikawa , Henki Rotinsulu , Remy E. P. Mangindaan and Michio Namikoshi
Article: Two New Tryptamine Derivatives, Leptoclinidamide and (-)-Leptoclinidamine B, from an Indonesian Ascidian Leptoclinides dubius
Mar. Drugs 2012, 10(2), 349-357; doi:10.3390/md10020349 - published online 10 February 2012
Show/Hide AbstractAbstract: Two new tryptamine-derived alkaloids, named as leptoclinidamide (1) and (-)-leptoclinidamine B (2), were isolated from an Indonesian ascidian Leptoclinides dubius together with C²-α-D-mannosylpyranosyl-L-tryptophan (3). The structure of 1 was assigned on the basis of spectroscopic data for 1 and its N-acetyl derivative (4). Compound 1 was an amide of tryptamine with two β-alanine units. Although the planar structure of 2 is identical to that of the known compound (+)-leptoclinidamine B (5), compound 2 was determined to be the enantiomer of 5 based on amino acid analysis using HPLC methods. Compounds 1 to 4 were evaluated for cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells, but none of the compounds showed activity.

Yongxiang Song , Jiajian Wang , Hongbo Huang , Lin Ma , Jun Wang , Yucheng Gu , Lan Liu and Yongcheng Lin
Article: Four Eremophilane Sesquiterpenes from the Mangrove Endophytic Fungus Xylaria sp. BL321
Mar. Drugs 2012, 10(2), 340-348; doi:10.3390/md10020340 - published online 6 February 2012
Show/Hide AbstractAbstract: Three new eremophilane sesquiterpenes (1–3) were isolated from the mangrove endophytic fungus Xylaria sp. BL321 together with 07H239-A (4), a known analogue of the new compounds. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. Compound 4 showed activation activity on α-glucosidase at 0.15 μM (146%), and then, 4 gradually produced inhibitory activity on α-glucosidase with increasing concentration, and the IC₅₀ value is 6.54 μM.

Erick J. Nuñez-Vazquez , Armando Garcia-Ortega , Angel I. Campa-Cordova , Isabel Abdo de la Parra , Lilia Ibarra-Martinez , Alejandra Heredia-Tapia and Jose L. Ochoa
Article: Toxicity of Cultured Bullseye Puffer Fish Sphoeroides annulatus
Mar. Drugs 2012, 10(2), 329-339; doi:10.3390/md10020329 - published online 3 February 2012
Show/Hide AbstractAbstract: The toxin content in various life cycle stages of tank-cultivated bullseye puffer (Sphoeroides annulatus) were analyzed by mouse bioassay and ESI-MS spectrometry analysis. The presence of toxin content was determined in extracts of sperm, eggs, embryo, larvae, post-larvae, juvenile, pre-adult, and adult fish, as well as in food items used during the cultivation of the species. Our findings show that only the muscle of juveniles, the viscera of pre-adults, and muscle, liver, and gonad of adult specimens were slightly toxic ( < 1 mouse unit). Thus, cultivated S. annulatus, as occurs with other cultivated puffer fish species, does not represent a food safety risk to consumers. This is the first report of toxin analysis covering the complete life stages of a puffer fish under controlled conditions.

Yongxin Li , Ying Xu , Lingli Liu , Zhuang Han , Pok Yui Lai , Xiangrong Guo , Xixiang Zhang , Wenhan Lin and Pei-Yuan Qian
Article: Five New Amicoumacins Isolated from a Marine-Derived Bacterium Bacillus subtilis
Mar. Drugs 2012, 10(2), 319-328; doi:10.3390/md10020319 - published online 3 February 2012
Show/Hide AbstractAbstract: Four novel amicoumacins, namely lipoamicoumacins A–D (1–4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature.

Shang-Kwei Wang and Chang-Yih Duh
Article: New Cytotoxic Cembranolides from the Soft Coral Lobophytum michaelae
Mar. Drugs 2012, 10(2), 306-318; doi:10.3390/md10020306 - published online 31 January 2012
Show/Hide AbstractAbstract: Six new cembranolides, michaolides L–Q (1–6), and a known cembranolide, lobomichaolide (7) were isolated from the CH₂Cl₂ extract of the soft coral Lobophytum michaelae. Their structures were established by extensive spectral analysis. The anti-HCMV (human cytomegalovirus) activity of 1–7 and their cytotoxicity against selected cell lines were evaluated.

Francisco Rafael Nieto , Enrique José Cobos , Miguel Ángel Tejada , Cristina Sánchez-Fernández , Rafael González-Cano and Cruz Miguel Cendán
Review: Tetrodotoxin (TTX) as a Therapeutic Agent for Pain
Mar. Drugs 2012, 10(2), 281-305; doi:10.3390/md10020281 - published online 31 January 2012
Show/Hide AbstractAbstract: Tetrodotoxin (TTX) is a potent neurotoxin that blocks voltage-gated sodium channels (VGSCs). VGSCs play a critical role in neuronal function under both physiological and pathological conditions. TTX has been extensively used to functionally characterize VGSCs, which can be classified as TTX-sensitive or TTX-resistant channels according to their sensitivity to this toxin. Alterations in the expression and/or function of some specific TTX-sensitive VGSCs have been implicated in a number of chronic pain conditions. The administration of TTX at doses below those that interfere with the generation and conduction of action potentials in normal (non-injured) nerves has been used in humans and experimental animals under different pain conditions. These data indicate a role for TTX as a potential therapeutic agent for pain. This review focuses on the preclinical and clinical evidence supporting a potential analgesic role for TTX. In addition, the contribution of specific TTX-sensitive VGSCs to pain is reviewed.