Antiprotozoal Linear Furanosesterterpenoids from the Marine Sponge Ircinia oros

Abstract

Chemical investigation of the marine sponge Ircinia oros yielded four linear furanosesterterpenoids, including the known metabolites ircinin-1 (1) and ircinin-2 (2) and two new compounds, ircinialactam E (3) and ircinialactam F (4). Their chemical structures were elucidated by using a combination of [α], NMR, HRMS, and FT-IR spectroscopy. The absolute configuration of C-18 in compounds 1-3 was identified as R by electronic circular dichroism (ECD) spectroscopy coupled with time-dependent density functional theory calculations. Compounds 1-4 showed moderate leishmanicidal, trypanocidal, and antiplasmodial activities (IC values 28-130 μM). This is the second report of rare glycinyl lactam derivatives 3 and 4 from the genus Ircinia.

Marine natural products

“…462 Linear furanosesterterpenoids are commonly reported from marine sponges. New variants were isolated from Ircinia 1167-1169, 463,464 Luffariella 1170, 1171 (ref. 465) and Psammocinia 1172-1174 (ref.…”

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…. positively influences the in vitro antiprotozoal activity" [92]; a new cyclic polyketide-peptide hybrid janadolide ( 94) from the Japanese marine cyanobaterium Okeania sp. which demonstrated very potent activity against T. brucei brucei, thus revealing potential for development as "new antitrypanosomal drugs" [93]; the cyclic pentapeptide malformin A1 (95) isolated from the Philippine marine seagrass-derived fungus Aspergillus tubingensis IFM 63452 highly active towards the parasite T. congolense and recommended as "an antiprotozoal agent" [94]; a novel azepino-diindole alkaloid rhodozepinone (96) isolated from a Red Sea marine sponge-derived bacterium Rhodococcus sp.…”

An Anti-Inflammatory 2,4-Cyclized-3,4-Secospongian Diterpenoid and Furanoterpene-Related Metabolites of a Marine Sponge Spongia sp. from the Red Sea

“…Marine sponges have been considered to be an important source for the discovery of structurally diverse bioactive secondary metabolites [1]. Many natural products from sponges have been shown to exhibit a variety of biological activities, such as antimicrobial [2][3][4][5], antiviral [6][7][8], antiprotozoal [8][9][10], cytotoxic [6,[11][12][13], anti-inflammatory [14][15][16], antioxidant [4,17,18], immunosuppressive [1,19,20], and antifeedant [21][22][23]. The genus Spongia (Spongidae) has been chemically investigated since 1971 [24] and the studies have led to the discovery of a series of furanoterpenes [24][25][26], spongian diterpenoids [27][28][29][30][31][32], scalarane sesterterpenoids [33][34][35], sesquiterpene quinones [36,37], along with other kinds of metabolites, for example, sterols [38][39][40] and macrolides…”