Atkamine: A New Pyrroloiminoquinone Scaffold from the Cold Water Aleutian Islands Latrunculia Sponge

Abstract

A new pyrroloiminoquinone alkaloid, named atkamine, with an unusual scaffold was discovered from a cold, deep water Alaskan sponge Latrunculia sp. collected from the Aleutian Islands. Olefin metathesis was utilized to determine the location of the double bond in the hydrocarbon chain. The absolute configuration was determined by using computational approaches combing with the ECD (electronic circular dichroism) spectroscopy.

New Discorhabdin B Dimers with Anticancer Activity from the Antarctic Deep-Sea Sponge Latrunculia biformis

“…The ECD spectroscopy was first employed in the structural elucidation of discorhabdins by Grkovic et al in 2008 [9]. Since then, this technique has become particularly attractive and useful for confirming the absolute configuration of discorhabdins because of their conformationally rigid structures, strong UV absorption and circular dichroism properties [10,11,13,21]. So far, ECD spectroscopy is also one of the most effective techniques to secure the absolute configurations of discorhabdins-type alkaloids with a large number of stereogenic centers.…”

“…So far, Latrunculia sponges represent one of the major reservoirs of pyrroloiminoquinone-type alkaloids. More than 40 pyrroloiminoquinone alkaloids belonging to the subclasses tsitsikammamines, makaluvamines, and discorhabdins have been reported from this genus, the discorhabdins being the largest and the most diverse [5,8,13,14]. Discorhabdins are a unique class of nitrogenous pigments possessing a characteristic tetracyclic pyrido [2,3-h]pyrrolo [4,3,2-de]quinoline core bound to a cyclohexanone substituent at the spiro center C-6 [5].…”

Monanchocidin A From Subarctic Sponges of the Genus Monanchora and Their Promising Selectivity Against Melanoma in vitro

“…Monanchocidin A was compared against all publicly available NCI-60 data using the CellMiner Database Version 1.4 (Reinhold et al, 2012). Utilizing the Compare (Zhou et al, 2000) algorithm and Pearson correlation coefficients, it was found that monanchocidin A shared a 0.638 Pearson correlation with ptilomycalin A (Figure 6). A Pearson correlation value above 0.6 is considered somewhat statistically significant.…”

Enantioselective Synthesis of Indolines, Benzodihydrothiophenes, and Indanes by C−H Insertion of Donor/Donor Carbenes

“…[11] Growing interest in sulfur-containing heterocycles as anti-tumor agents emphasizes the need for new method development in this area. [12] To date, there is only a single report of a benzodihydrothiophene synthesis employing rhodium carbenes with acceptor-substituted diazo compounds. [13] The authors of this study hypothesize that the lack of development of this methodology is due to a propensity of the highly nucleophilic sulfur atom to attack the carbene directly to form an ylide.…”