Laurent Calcul

Dr. Laurent Calcul

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 December 2013 in Marine Drugs
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LCLaurent Calcul
Laurent Calcul
CWCarrie Waterman
Carrie Waterman
WMWai Sheung Ma
Wai Sheung Ma
MLMatthew D Lebar
Matthew D Lebar
CHCharles Harter
Charles Harter
Bill BakerBill Baker
Bill Baker
We conducted a screening campaign to investigate fungi as a source for new antimalarial compounds. A subset of our fungal collection comprising Chinese mangrove endophytes provided over 5000 lipophilic extracts. We developed an accelerated discovery program based on small-scale cultivation for crude extract screening and a high-throughput malaria assay. Criteria for hits were developed and high priority hits were subjected to scale-up cultivation. Extracts from large scale cultivation were fractionated and these fractions subjected to both in vitro malaria and cytotoxicity screening. Criteria for advancing fractions to purification were developed, including the introduction of a selectivity index and by dereplication of known metabolites. From the Chinese mangrove endophytes, four new compounds (14–16, 18) were isolated including a new dimeric tetrahydroxanthone, dicerandrol D (14), which was found to display the most favorable bioactivity profile.

11 June 2010 in Australian Journal of Chemistry
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LCLaurent Calcul
Laurent Calcul
KTKaren Tenney
Karen Tenney
JRJoseline Ratnam
Joseline Ratnam
JMJames H. McKerrow
James H. McKerrow
PCPhil Crews
Phil Crews
Four novel 9-N-methyladeninium diterpenoids, agelasine M (3), 2-oxo-agelasine B (4), gelasine A (5), and gelasine B (6) accompanied by the known-agelasine B (1) and F (2) were isolated from the marine sponge Agelas sp. collected in Papua New Guinea. Compounds 3–6 represent higher unsaturated 9-N-methyladeninium bicyclic diterpenoid derivatives including 5 and 6 as unusual norditerpenoid-agelasines. Their structures were elucidated through detailed physical data analyses and comparison with literature properties. All pure compounds were evaluated for inhibitory activity against Trypanosoma brucei as well as for cytotoxicity against Jurkat cells.

8 March 2022 in Marine Drugs
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SKSofia Kokkaliari
Sofia Kokkaliari
KPKim Pham
Kim Pham
NSNargess Shahbazi
Nargess Shahbazi
LCLaurent Calcul
Laurent Calcul
LWLukasz Wojtas
Lukasz Wojtas
Bill BakerBill Baker
Bill Baker
Five new alkaloids have been isolated from the lipophilic extract of the Antarctic tunicate Synoicum sp. Deep-sea specimens of Synoicum sp. were collected during a 2011 cruise of the R/V Nathanial B. Palmer to the southern Scotia Arc, Antarctica. Crude extracts from the invertebrates obtained during the cruise were screened in a zebrafish-based phenotypic assay. The Synoicum sp. extract induced embryonic dysmorphology characterized by axis truncation, leading to the isolation of aminopyrimidine substituted indolone (1–4) and indole (5–12) alkaloids. While the primary bioactivity tracked with previously reported meridianins A–G (5–11), further investigation resulted in the isolation and characterization of australindolones A–D (1–4) and the previously unreported meridianin H (12).

29 October 2023 in Life
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Maheen GullMaheen Gull
Maheen Gull
TFTian Feng
Tian Feng
BSBenjamin Smith
Benjamin Smith
LCLaurent Calcul
Laurent Calcul
Matthew PasekMatthew Pasek
Matthew Pasek
Reduced-oxidation-state phosphorus (reduced P, hereafter) compounds were likely available on the early Earth via meteorites or through various geologic processes. Due to their reactivity and high solubility, these compounds could have played a significant role in the origin of various organophosphorus compounds of biochemical significance. In the present work, we study the reactions between reduced P compounds and their oxidation products, with the three nucleosides (uridine, adenosine, and cytidine), with organic alcohols (glycerol and ethanolamine), and with the tertiary ammonium organic compound, choline chloride. These reactions were studied in the non-aqueous solvent formamide and in a semi-aqueous solvent comprised of urea: ammonium formate: water (UAFW, hereafter) at temperatures of 55–68 °C. The inorganic P compounds generated through Fenton chemistry readily dissolve in the non-aqueous and semi-aqueous solvents and react with organics to form organophosphites and organophosphates, including those which are identified as phosphate diesters. This dual approach (1) use of non-aqueous and semi-aqueous solvents and (2) use of a reactive inorganic P source to promote phosphorylation and phosphonylation reactions of organics readily promoted anhydrous chemistry and condensation reactions, without requiring any additive, catalyst, or other promoting agent under mild heating conditions. We also present a comparative study of the release of P from various prebiotically relevant phosphate minerals and phosphite salts (e.g., vivianite, apatite, and phosphites of iron and calcium) into formamide and UAFW. These results have direct implications for the origin of biological P compounds from non-aqueous solvents of prebiotic provenance.

27 June 2025 in Environments
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EBElzbieta Bialkowska-Jelinska
Elzbieta Bialkowska-Jelinska
PBPhilip van Beynen
Philip van Beynen
LCLaurent Calcul
Laurent Calcul
Shallow lakes are highly vulnerable to pollution due to their small water volume. Those that receive effluent from the drainfields of onsite wastewater treatment systems (septic tanks) may contain pharmaceuticals and personal care products (PPCPs) that escaped removal during treatment. This study examined the effects of seasonal rainfall variability on the assemblages and concentrations of fourteen PPCPs in two shallow lakes in West–Central Florida, USA: one surrounded by residents equipped with septic tanks and the other located within a nature preserve. Water samples were collected weekly during an 18-week interval from April to August 2021. Liquid chromatography–mass spectrometry analyses revealed the omnipresence of five PPCPs: theophylline, caffeine, cotinine, DEET, and testosterone, although acetaminophen, ibuprofen, and sulfamethoxazole were also common. Of all the PPCPs detected, theophylline, DEET, and acetaminophen concentrations were higher during the wet season in the septic tank-influenced lake, while caffeine, cotinine, and testosterone concentrations decreased. In the lake located in the nature preserve, theophylline, caffeine, and acetaminophen levels increased in the wet season. In contrast, cotinine, DEET, and testosterone levels decreased. Overall, more compounds were detected during the wet season, with highly hydrophobic PPCPs (fluoxetine, atorvastatin, and octocrylene) only present during this period.

8 July 2025 in Environments
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EBElzbieta Bialkowska-Jelinska
Elzbieta Bialkowska-Jelinska
PBPhilip van Beynen
Philip van Beynen
LCLaurent Calcul
Laurent Calcul
The use of pharmaceuticals and personal care products (PPCPs) is steadily growing as the world’s population both increases and ages. Many of these products are released into the environment via municipal wastewater treatment plants and onsite wastewater treatment systems (septic tanks). Consequently, it is essential to ascertain whether these contaminants pose any risk to aquatic organisms who live in the water bodies receiving this waste. Risk quotients (RQ) are a commonly used method to do so. For our pilot study, we undertook such analysis for three trophic levels: algae, crustaceans, and fish from two small lakes, one fed by septic tanks and the other not. This research was conducted in 2021 from the end of the dry season and through most of the wet season in west central Florida, USA. Of the 14 PPCPs measured, six had RQs that posed a risk to all three trophic levels. This risk increased during the wet season. Both lakes, regardless of whether they directly received PPCPs from septic tanks or not, had some level of risk. However, the lake without septic tanks had a smaller risk, both in elevated RQs and the occurrence to the various species. Of the PPCPs measured, DEET, caffeine, and theophylline posed the greatest risk.