Antiparasitic Activity of Bromotyrosine Alkaloids and New Analogues Isolated from the Fijian Marine Sponge Aplysinella rhax

Abstract

Ten bromotyrosine alkaloids were isolated and characterised from the marine sponge Aplysinella rhax (de Laubenfels 1954) collected from the Fiji Islands, which included one new bromotyrosine analogue, psammaplin P and two other analogues, psammaplin O and 3-bromo-2-hydroxy-5-(methoxycarbonyl)benzoic acid, which have not been previously reported from natural sources. HR-ESI-MS, 1D and 2D NMR spectroscopic methods were used in the elucidation of the compounds. Bisaprasin, a biphenylic dimer of psammaplin A, showed moderate activity with IC 50 at 19 � 5 and 29 � 6 μM against Trypanzoma cruzi Tulahuen C4, and the lethal human malaria species Plasmodium falciparum clone 3D7, respectively, while psammaplins A and D exhibited low activity against both parasites. This is the first report of the antimalarial and antitrypanosomal activity of the psammaplin-type compounds. Additionally, the biosynthesis hypotheses of three natural products were proposed.

Inhibition of Quorum Sensing System inPseudomonas aeruginosaby Psammaplin A and Bisaprasin Isolated from the Marine SpongeAplysinella rhax

“…The marine sponge extract was partitioned between water and dichloromethane (50% v/v) using a modified Kupchan method previously described (Oluwabusola et al 2020)…”

“…an Agilent 6540 HRESI-TOF-MS coupled to an Agilent 1200 HPLC system. This procedure was explained in detail in the previous publication (Oluwabusola et al 2020).…”

“…Psammaplin A (1) is composed of two modified amino acids: a bromotyrosine containing an oxime group, and cysteamines that form the disulfide bridge (Rodriguez et al 1987). The bromotyrosine compound (1) and its derivatives have shown to possess good cytotoxicity against ovarian tumour cell lines (Tabudravu et al 2002), considerable antibacterial activity against gram-positive methicillin-resistant S. aureus, inhibition of DNA synthesis and the supercoiling activity of DNA gyrase ( Kim et al 1999), and antiparasitic activity (Oluwabusola et al 2020). The current study was conducted against the backdrop of interesting biological activities of these type of bromotyrosine compounds.…”

“…The compounds were previously isolated alongside psammaplins B - D (Rodriguez et al . 1987; Jimenez and Crews, 1991; Park et al ., 2003) and O - P , 3-bromo-2-hydroxyl-6-carbomethoxy benzoic acid (Oluwabusola et al . 2020), 2-(3-bromo-4-hydroxyphenyl) aceto-nitrile and 3-bromo-4-hydroxybenzoic acid from the methanolic extract of the marine sponge, Aplysinella rhax , collected from the Fiji islands and were subjected to QS inhibitory screening.…”

“…2002), considerable antibacterial activity against gram-positive methicillin-resistant S. aureus , inhibition of DNA synthesis and the supercoiling activity of DNA gyrase (Kim et al . 1999), and antiparasitic activity (Oluwabusola et al . 2020).…”