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Huxley C, Wibowo M, Lum KY, Gordon S, D'Hyon S, Guan H, Wang X, Chen Y, Si M, Wang M, White JM, Wahi K, Wang Q, Holst J, Davis RA. Synthesis of bilocularin A carbamate derivatives and their evaluation as leucine transport inhibitors in prostate cancer cells. PHYTOCHEMISTRY 2020; 179:112478. [PMID: 32805621 DOI: 10.1016/j.phytochem.2020.112478] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/08/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Large-scale extraction of the leaves of the Australian rainforest tree Maytenus bilocularis followed by extensive purification studies afforded the targeted and abundant dihydro-β-agarofuran, bilocularin A, in sufficient quantities (>500 mg) for detailed semi-synthetic chemistry. Eight bilocularin A carbamate analogues were synthesised using a series of commercially available isocyanate reagents in high purity (>95%) and variable yields (9-91%). All previously undescribed analogues were spectroscopically characterised using NMR, UV, IR and MS data. One compound afforded crystalline material and subsequent single crystal X-ray analysis (Cu-Kα) confirmed the chemical structure along with the absolute configuration. All compounds were evaluated for anti-proliferative activity against the human prostate cancer cell line LNCaP; none of the compounds showed significant (>50%) growth inhibition at 20 μM. Compounds were also tested for their ability to inhibit leucine transport in LNCaP cells, and two analogues showed moderate activity with IC50 values of 8.9 and 8.5 μM. This is the first reported synthesis of dihydro-β-agarofuran carbamate derivatives.
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Affiliation(s)
- Cohan Huxley
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Mario Wibowo
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Kah Yean Lum
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Shelly Gordon
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Sebastian D'Hyon
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Hanyu Guan
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Xueyi Wang
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Yuxi Chen
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Mingran Si
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Mengchao Wang
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Jonathan M White
- School of Chemistry and Bio 21 Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kanu Wahi
- Translational Cancer Metabolism Laboratory, School of Medical Sciences and Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Qian Wang
- Translational Cancer Metabolism Laboratory, School of Medical Sciences and Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Jeff Holst
- Translational Cancer Metabolism Laboratory, School of Medical Sciences and Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia.
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Natural Compounds from the Marine Brown Alga Caulocystis cephalornithos with Potent In Vitro-Activity against the Parasitic Nematode Haemonchus contortus. Pathogens 2020; 9:pathogens9070550. [PMID: 32659883 PMCID: PMC7400099 DOI: 10.3390/pathogens9070550] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Eight secondary metabolites (1 to 8) were isolated from a marine sponge, a marine alga and three terrestrial plants collected in Australia and subsequently chemically characterised. Here, these natural product-derived compounds were screened for in vitro-anthelmintic activity against the larvae and adult stages of Haemonchus contortus (barber's pole worm)-a highly pathogenic parasitic nematode of ruminants. Using an optimised, whole-organism screening system, compounds were tested on exsheathed third-stage larvae (xL3s) and fourth-stage larvae (L4s). Anthelmintic activity was initially evaluated on these stages based on the inhibition of motility, development and/or changes in morphology (phenotype). We identified two compounds, 6-undecylsalicylic acid (3) and 6-tridecylsalicylic acid (4) isolated from the marine brown alga, Caulocystis cephalornithos, with inhibitory effects on xL3 and L4 motility and larval development, and the induction of a "skinny-straight" phenotype. Subsequent testing showed that these two compounds had an acute nematocidal effect (within 1-12 h) on adult males and females of H. contortus. Ultrastructural analysis of adult worms treated with compound 4 revealed significant damage to subcuticular musculature and associated tissues and cellular organelles including mitochondria. In conclusion, the present study has discovered two algal compounds possessing acute anthelmintic effects and with potential for hit-to-lead progression. Future work should focus on undertaking a structure-activity relationship study and on elucidating the mode(s) of action of optimised compounds.
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