http://www.mdpi.com/journal/marinedrugs/special_issues/alkaloid-analogs/ Submission All papers should be submitted to marinedrugs@mdpi.com with copy to the Editors. To be published continuously until the deadline and papers will be listed together at the special websites. Both, research articles and review articles are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editors for announcment on this website. Submitted papers should not have been published previously, nor be under consideration for publication elsewhere. All papers are refereed through a peer-review process. A guide for authors, sample copies and other relevant information for submitting papers are available on the Instructions for Authors page. Marine Drugs is an international peer-reviewed quarterly journal published by MDPI. Please visit the Instructions for Authors page before submitting a paper. Open Access publication fees are 1000 CHF per paper. English correction fees (250 CHF) will be added in certain cases (1250 CHF per paper for those papers that require extensive additional formatting and/or English corrections.). http://www.mdpi.com/1660-3397/8/8/2395/ There are several avenues by which promising bioactive natural products can be produced in sufficient quantities to enable lead optimization and medicinal chemistry studies. The total synthesis of natural products is an important, but sometimes difficult, approach and requires the development of innovative synthetic methodologies to simplify the synthesis of complex molecules. Various classes of natural product alkaloids are both common and widely distributed in plants, bacteria, fungi, insects and marine organisms. This mini-review will discuss the scope, mechanistic insights and enantioselectivity aspects of selected examples of recently developed one-pot methods that have been published in 2009 for the synthesis of substituted piperidines, quinolizidines, pyrrolidines, hexahydropyrrolizines, octahydroindolizines and g-lactams. In addition, progress on the synthesis of b-carboline (manzamine) alkaloids will also be discussed. http://www.mdpi.com/1660-3397/8/8/2395/ Tue, 24 Aug 2010 00:00:00 CEST Marine Drugs 2010-08-24 8 8 Review 2395 2416 1660-3397 New One-Pot Methodologies for the Modification or Synthesis of Alkaloid Scaffolds 2010-08-24 doi: 10.3390/md8082395 Amir E. Wahba Mark T. Hamann http://www.mdpi.com/1660-3397/8/7/2185/ Saxitoxin (STX) and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs). PSTs are the causative agents of paralytic shellfish poisoning (PSP) and are mostly associated with marine dinoflagellates (eukaryotes) and freshwater cyanobacteria (prokaryotes), which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids. http://www.mdpi.com/1660-3397/8/7/2185/ Tue, 20 Jul 2010 00:00:00 CEST Marine Drugs 2010-07-20 8 7 Review 2185 2211 1660-3397 Neurotoxic Alkaloids: Saxitoxin and Its Analogs 2010-07-20 doi: 10.3390/md8072185 Maria Wiese Paul M. D’Agostino Troco K. Mihali Michelle C. Moffitt Brett A. Neilan http://www.mdpi.com/1660-3397/8/2/269/ This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review, a detailed account of macro algae alkaloids with their structure and pharmacological activities is presented. The alkaloids found in marine algae may be divided into three groups: 1. Phenylethylamine alkaloids, 2. Indole and halogenated indole alkaloids, 3. Other alkaloids. http://www.mdpi.com/1660-3397/8/2/269/ Thu, 04 Feb 2010 00:00:00 CET Marine Drugs 2010-02-04 8 2 Review 269 284 1660-3397 Alkaloids in Marine Algae 2010-02-04 doi: 10.3390/md8020269 Kasım Cemal Güven Aline Percot Ekrem Sezik http://www.mdpi.com/1660-3397/7/4/833/ Agelasines, asmarines and related compounds are natural products with a hybrid terpene-purine structure isolated from numerous genera of sponges (Agela sp., Raspailia sp.). Some agelasine analogs and related structures have displayed high general toxicity towards protozoa, and have exhibited broad-spectrum antimicrobial activity against a variety of species, including Mycobacterium tuberculosis, and also an important cytotoxic activity against several cancer cell lines, including multidrug-resistant ones. Of particular interest in this context are the asmarines (tetrahydro[1,4]diazepino[1,2,3-g,h]purines), which have shown potent antiproliferative activity against several types of human cancer cell lines. This review summarizes the sources of isolation, chemistry and bioactivity of marine alkylpurines and their bioactive derivatives. http://www.mdpi.com/1660-3397/7/4/833/ Wed, 23 Dec 2009 00:00:00 CET Marine Drugs 2009-12-23 7 4 Review 833 849 1660-3397 Terpenyl-Purines from the Sea 2009-12-23 doi: 10.3390/md7040833 Marina Gordaliza http://www.mdpi.com/1660-3397/7/4/754/ Granulatimide and isogranulatimide are alkaloids obtained from marine sources which have been shown to inhibit cell-cycle G2-checkpoint, targeting more particularly checkpoint 1 kinase (Chk1). At a structural level, they possess a characteristic pyrrolocarbazole framework also shared by the well-known rebeccamycin and staurosporine microbial metabolites which have been described to inhibit topoisomerase I and diverse kinases, respectively. This review reports precisely on the synthesis and kinase inhibitory activities of pyrrolocarbazole-based analogues of granulatimide. http://www.mdpi.com/1660-3397/7/4/754/ Tue, 01 Dec 2009 00:00:00 CET Marine Drugs 2009-12-01 7 4 Review 754 786 1660-3397 Marine Pyrrolocarbazoles and Analogues: Synthesis and Kinase Inhibition 2009-12-01 doi: 10.3390/md7040754 Sébastien Deslandes Stefan Chassaing Evelyne Delfourne http://www.mdpi.com/1660-3397/7/2/258/ The Active Peptide from Shark Liver (APSL) was expressed in E. coli BL21 cells. The cDNA encoding APSL protein was obtained from shark regenerated hepatic tissue by RT-PCR, then it was cloned in the pET-28a expression vector. The expressed fusion protein was purified by Ni-IDA affinity chromatography. SDS-PAGE and HPLC analysis showed the purity of the purified fusion protein was more than 98%. The recombinant APSL (rAPSL) was tested for its biological activity both in vitro, by its ability to improve the proliferation of SMMC7721 cells, and in vivo, by its significant protective effects against acute hepatic injury induced by CCl4 and AAP (acetaminophen) in mice. In addition, the rAPSL could decrease the blood glucose concentration of mice with diabetes mellitus induced by alloxan. Paraffin sections of mouse pancreas tissues showed that rAPSL (3 mg/kg) could effectively protect mouse islets from lesions induced by alloxan, which indicated its potential application in theoretical research and industry. http://www.mdpi.com/1660-3397/7/2/258/ Mon, 22 Jun 2009 00:00:00 CEST Marine Drugs 2009-06-22 7 2 Article 258 267 1660-3397 Expression, Purification and Bioactivities Analysis of Recombinant Active Peptide from Shark Liver 2009-06-22 doi: 10.3390/md7020258 Zhengbing Lv Yu Ou Qian Li Wenping Zhang Boping Ye Wutong Wu