Two Steroidal Alkaloids from a Sponge, Corticium Sp.

Abstract

Lokysterolamine A and B are two steroidal alkaloids isolated from an undescribed species of the sponge genus Corticium, collected in Sulawesi, Indonesia. Compound A is N,N-dimethyl- and B is N-acetyl-4 beta-hydroxy-3-epi-plakinamine A.

Metabolic fingerprinting as an indicator of biodiversity: towards understanding inter-specific relationships among Homoscleromorpha sponges

“…Plakinamine A and B, first reported from the genus Plakina (Rosser and Faulkner 1984) were afterwards identified in different specimens of the Corticium genus. Due to the high bioactivity displayed by specimens of the Corticium genus, an exhaustive chemical study was undertaken, which led to the isolation and characterization of numerous steroidal alkaloids called plakinamines (A-K), lokysterolamines and cortistatins (A-L) (Aoki et al 2006;Aoki et al 2007;Borbone et al 2002;De Marino et al 1999;Jurek et al 1994;Lee et al 2001;McCarthy et al 1992;Ridley and Faulkner 2003;Watanabe et al 2007). They display significant antimicrobial, cytotoxic and antiproliferative activities.…”

Isolation of Plakinamine I: A New Steroidal Alkaloid from the Marine Sponge Corticium sp. and Synthesis of an Analogue Model Compound

“…The bioactive chloroform extract (6.6 g) was fractionated in six runs by DCCC using CHCl 3 /MeOH/H 2 O (7:13:8) in the ascending mode (the lower phase was the stationary phase). Fractions (6 mL each) were collected and examined by TLC on SiO 2 3α-Azido-5α-cholestan-6-one (3): Et 3 N (7.6 mL, 54.6 mmol) and methanesulfonyl chloride (3.38 mL, 49.6 mmol) were sequentially added to a solution of 3β-hydroxy-5α-cholestan-6-one (2, 1.0 g, 2.48 mmol) in dry Et 2 O. The reaction mixture was cooled to -10°C for 10 min and was then stirred at room temperature for 3 h. The mixture was diluted with water and extracted with CHCl 3 .…”

“…The marine sponge Corticium sp. represents a prolific source of new steroidal alkaloids: [1][2][3][4][5][6][7] the majority are structurally related to plakinamine A, as they possess an amino group at C-3 and a cyclic imine functionality on the side chain of a C 29 steroidal framework. From the same sponge, two new derivatives featuring an unusual B(9a)-homo-19-nor steroidal nucleus have also been isolated.…”

Synthesis of (E)‐3‐Alkylidene‐1‐pyrrolines by the Rhodium‐ Catalyzed Cyclization of Terminal Alkynes with Homopropargylic Amines

“…The 3-alkylidene-1-pyrroline framework is stable and is frequently found in natural products such as lanopylines [1] and lokysterolamines, [2] in synthetic biologically active molecules, [3] and in photoisomerization molecules. [4] This unique structure can be prepared by the condensation of 1-pyrrolines with aldehydes [5] or enamines [6] in the absence or presence of an acid catalyst.…”

“…An NOE experiment confirmed the stereochemistry of 3aa as being an Eisomer. Whereas the addition of NH 4 BF 4 to the reaction mixture was required to afford 3aa when RhClA C H T U N G T R E N N U N G (PPh 3 ) 3 was used as a catalyst (entry 2), [Rh- 2 ]BF 4 /PPh 3 catalyzed the reaction, even in the absence of the ammonium salt (entry 3). These results indicate that a cationic rhodium complex can serve as an active catalytic species.…”