Keikipukalides, Furanocembrane Diterpenes from the Antarctic Deep Sea Octocoral Plumarella delicatissima

Abstract

During a 2013 cruise in the Southern Ocean we collected specimens of the octocoral Plumarella delicatissima between 800 and 950 m depth. Five new furanocembranoid diterpenes, keikipukalides A–E (1–5), the known diterpene pukalide aldehyde (6), and the known norditerpenoid ineleganolide (7) were isolated from the coral. These Plumarella terpenes lack mammalian cytotoxicity, while 2–7 display activity against Leishmania donovani between 1.9 and 12 μM. Structure elucidation was facilitated by one- and two-dimensional NMR spectroscopy and mass spectrometry, and keikipukalides A and E were confirmed by X-ray crystallography.

Biosynthetic Interrelationships within Polycyclic Cembranoids Isolated from Corals: Conjecture, Biomimetic Synthesis and Reality

“…Up until very recently a perplexing issue with the aforementioned biosynthetic proposals for plumarellide, rameswaralide and the mandapamates was that no FBC epoxide or similar precursor having 1,3‐diene functionality between C11 and C14 had been described in corals. This changed in 2018 when Baker et al uncovered the keikipukalides 56 and 57 (Figure ), displaying such unsaturation, in the deep sea octocoral Plumarella delicatissima collected from the “Plateau of Fascination” northeast of Stanley, Falkland Islands in the Southern Ocean. The characterisation of the keikipukalides has given some credence to, and confidence in the broad proposals put forward in Scheme and Scheme to plumarellide 9 and rameswaralide 10 .…”

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles

“…3 a) Diterpene Shore of Kilkee brown alga Bifurcaria bifurcate Ireland [ 29 ] L. donovani amastigotes (NA) A549 (> 50 μmol/L) Keikipukalides (1), Diterpene (Fig. 3 b) Antarctic deep-sea octocoral—Cnidaria Plumarella delicatissima Falkland Islands (Islas Malvinas) [ 30 ] L. donovani amastigotes (1.9–12 μmol/L) Keikipukalides (2–5), pukalide aldehyde (6), and norditerpenoid ineleganolide (7) L. amazonensis promastigotes (15.47 ± 0.26 and 36.81 ± 5.20 μmol/L) and T. cruzi epimastigotes ( 5.62 ± 2.48 and 35.29 ± 4.09 μmol/L) J774.A1 (23.4 ± 5.62 μmol/L and 69.98 ± 0.14 μmol/L) Spiralyde A (1) and 3,4-epoxy-7,18-dolabelladiene (2) (Fig. 3 c) Diterpene Off the coast (1.5 m) brown alga Dictyota spiralis Tunisia [ 31 ] L. amazonensis and T. cruzi (> 100.00 μmol/L) NT Compounds 3–6 P. falciparum strain Dd2 trophozoites (3.51, 2.11 and 0.8 µmol/L) NT Smenotronic acid (1), ilimaquinone (2), and pelorol (3) (Fig.…”

“…3 b). This family of diterpenes (2–7) exhibited antileishmanial activity against L. donovani (IC 50 = 1.9–12 μmol/L) and showed no cytotoxic effect against human lung carcinoma cells A549 (> 50 μmol/L) [ 30 ].…”

Use of Natural Products in Leishmaniasis Chemotherapy: An Overview

“…X-ray crystallography of all isolated terpenoids indicates the differences between Pulmarella sp. terpenoid chemical structure, which is an important first step in structure-activity studies that should be conducted in further research (Thomas et al, 2018).…”