A. Jonathan Singh

ORCID: 0000-0003-1722-066X
Publications
Citations
Views
---
Saved
---
About
Contact & Profiles
Research Areas
  • Marine Sponges and Natural Products
  • Synthetic Organic Chemistry Methods
  • Microbial Natural Products and Biosynthesis
  • Cancer Treatment and Pharmacology
  • Click Chemistry and Applications
  • X-ray Diffraction in Crystallography
  • Plant biochemistry and biosynthesis
  • Crystallization and Solubility Studies
  • Synthesis and biological activity
  • SARS-CoV-2 and COVID-19 Research
  • Alkaloids: synthesis and pharmacology
  • Microtubule and mitosis dynamics
  • Multicomponent Synthesis of Heterocycles
  • Advanced Proteomics Techniques and Applications
  • Genomics and Phylogenetic Studies
  • Cancer-related Molecular Pathways
  • Synthesis and bioactivity of alkaloids
  • Cancer therapeutics and mechanisms
  • 14-3-3 protein interactions
  • Bacteriophages and microbial interactions
  • Histone Deacetylase Inhibitors Research
  • Protein Degradation and Inhibitors
  • Synthesis and Biological Evaluation
  • Traditional and Medicinal Uses of Annonaceae
  • Molecular Biology Techniques and Applications

Victoria University of Wellington
2013-2025

Maurice Wilkins Centre
2022-2025

University of Auckland
2024-2025

Institute of Genetics and Cancer
2020-2024

University of Edinburgh
2020-2024

Edinburgh Cancer Research
2022

Masaryk Memorial Cancer Institute
2021

University of Gdańsk
2020

National Cancer Institute
2016-2018

Center for Cancer Research
2016-2018

An important stage in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) life cycle is the binding of spike (S) protein to angiotensin converting enzyme-2 (ACE2) host cell receptor. Therefore, explore conserved features dynamics and identify potentially novel regions for drugging, we measured variability derived from 791 viral genomes studied its properties by molecular (MD) simulation. The findings indicated that S2 subunit (heptad-repeat 1 (HR1), central helix (CH), connector...

10.3390/jcm9051473 article EN Journal of Clinical Medicine 2020-05-14

Zampanolide (1), a 20-membered macrolide from Tongan marine sponge, stabilizes microtubules and blocks cells in G2/M of the cell cycle. is cytotoxic low nanomolar range induces microtubule bundles cells. It leads to tubulin assembly purified preparations not substrate for P-glycoprotein drug efflux pump. Zampanolide, with only four stereogenic centers, may be amenable large-scale synthetic preparation.

10.1021/jm901249g article EN Journal of Medicinal Chemistry 2009-10-30

Histone deacetylase inhibitors (HDACi) have been actively explored as anti-cancer agents due to their ability prevent deacetylation of histones, resulting in uncoiling chromatin and stimulation a range genes associated the regulation cell survival, proliferation, differentiation apoptosis. During past several years, many HDACi entered pre-clinical or clinical research with satisfying results. Out these, more than 8 novel hydroxamic acid based i.e., belinostat, abexinostat, SB939,...

10.2174/09298673113209990191 article EN Current Medicinal Chemistry 2013-07-23

The NMR-directed investigation of the New Zealand marine sponge Hamigera tarangaensis has afforded ten new compounds hamigeran family, and a 13-epi-verrucosane congener. Notably, F (6) possesses an unusual carbon–carbon bond between C-12 C-13, creating unprecedented skeleton within this class. In particular, structural features 6, H (10) J (12) imply diterpenoid origin, which allowed putative biogenesis three carbon skeletons to be proposed based on geranyl pyrophosphate. All hamigerans...

10.1039/c3ob41305e article EN Organic & Biomolecular Chemistry 2013-01-01

Imidazole-based compounds are attractive targets in the design of novel chemical structures for discovery new drugs. In current study, we have synthesized a series 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles by multicomponent reaction (MCR). Vanillin isovanillin derivatives were reacted with benzil/pyridil diverse amines ammonium acetate acetic acid at 50–110 °C 24 h to afford respective 55–70% yields. The molecules evaluated anti-cancer potential against National Cancer...

10.1039/c4md00277f article EN MedChemComm 2014-08-28

Peloruside B (2), a natural congener of peloruside A (1), was isolated in sub-milligram quantities from the New Zealand marine sponge Mycale hentscheli. promotes microtubule polymerization and arrests cells G2/M phase mitosis similar to paclitaxel, its bioactivity comparable that A. NMR-directed isolation, structure elucidation, confirmation by total synthesis, are described this article. The synthesis features Sharpless dihydroxylation, Brown's asymmetric allylboration reaction, reductive...

10.1021/jo9021265 article EN The Journal of Organic Chemistry 2009-12-03

The NMR-directed isolation and structure elucidation of nine new nitrogenous hamigeran diterpenoids from the New Zealand marine sponge Hamigera tarangaensis are described. Featured in this set oxazole-containing M (4) eight compounds (5a-6a 7a-8c) related to constitutional D (1). Moderate cytotoxicity low-micromolar range against HL-60 promyeloid leukemic cell line is reported for seven compounds. structural nature these suggests that their adducts derived an amino acid source has allowed...

10.1021/jo502370b article EN The Journal of Organic Chemistry 2014-11-25

The significant structural diversity and potent bioactivity of the fungal indole diterpenes (IDTs) has attracted considerable interest in their biosynthesis. Although substantial skeletal is generated by action noncanonical terpene cyclases, comparatively little known about these enzymes, particularly those involved generation subgroup containing emindole SA DA, which show alternate terpenoid skeletons. Here, we describe IDT biosynthetic machinery generating unusual architectures from...

10.1021/jacs.2c11170 article EN cc-by-nc-nd Journal of the American Chemical Society 2023-01-30

Sponges in the verongiid genus Pseudoceratina Carter are well-known producers of bioactive secondary metabolites. Chemical screening a Tongan P. cf. verrucosa Bergquist using NMR highlighted presence aromatic natural products. Subsequent extraction and purification yielded new bromotyrosine, purpuramine R (1), that exhibits moderate (MIC 16 µg/mL) antibacterial activity against Gram-positive Staphylococcus aureus. The E-geometry oxime was confirmed combination computational approaches....

10.3390/md23050186 article EN cc-by Marine Drugs 2025-04-27

Two new peloruside congeners (3 and 4) were isolated from wild aquacultured collections of the New Zealand marine sponge Mycale hentscheli. Small-scale reactions on A (1) have been performed, which along with isolation 3 4, give further insight into bioactive pharmacophore 1.

10.1039/c0ob01127d article EN Organic & Biomolecular Chemistry 2011-01-01

Herein we report on the Electrophile Induced Branching Cascade (EIBC), a new technique to produce variety of biologically important molecular scaffolds. Some compounds exhibit excellent activities against Mycobacterium smegmatis.

10.1039/c3cc45289a article EN Chemical Communications 2013-01-01

Four new compounds (2–5) structurally related to the microtubule-stabilizing agent (−)-zampanolide (1) have been isolated from Tongan marine sponge Cacospongia mycofijiensis. Three of these structures, zampanolides B–D (2–4), exhibit nanomolar cytotoxicity toward HL-60 cell line, are antimitotic, and induce in vitro tubulin polymerization at levels comparable 1. Zampanolide E (5), saturated C-8/C-9, was significantly less potent does not stabilize purified tubulin, even 10-fold higher...

10.1021/acs.jnatprod.8b00641 article EN Journal of Natural Products 2018-10-29

An important stage in SARS-CoV-2 life cycle is the fusion of spike(S) protein with ACE2 host-cell receptor. Therefore, to explore conserved features S dynamics and identify potentially novel regions for drugging, we measured variability derived from 791 viral genomes studied its properties by MD simulation. The findings indicated that S2 subunit (HR1, CH, CD domains) showed low variability, fluctuations MD, displayed a trimer cavity. By contrast, RBD domain, which typically targeted drug...

10.20944/preprints202004.0439.v1 preprint EN 2020-04-24

Moving from macroscale preparative systems in proteomics to micro- and nanotechnologies offers researchers the ability deeply profile smaller numbers of cells that are more likely be encountered clinical settings. Herein a recently developed microscale proteomic method, microdroplet processing one pot for trace samples (microPOTS), was employed identify changes ∼200 Barrett's esophageal following physiologic radiation stress exposure. From this small population cells, microPOTS confidently...

10.1021/acs.jproteome.0c00629 article EN cc-by Journal of Proteome Research 2021-01-25

Abstract Nodulisporic acids (NAs) are structurally complex potent antiinsectan indole diterpenes. We previously reported the biosynthetic gene cluster for these metabolites in Hypoxylon pulicicidum and functionally characterised first five steps of pathway. Here we reveal a highly array, furnishing multiple end products through expression components Penicillium paxilli . show that seven additional cluster‐encoded comprise machinery elaborate precursor NAF this branched The combined action...

10.1002/anie.202213364 article EN cc-by-nc-nd Angewandte Chemie International Edition 2022-10-06

Seven new members of the hamigeran family diterpenoids have been isolated from New Zealand marine sponge Hamigera tarangaensis. Among additions are R (1), considered to be first benzonitrile-based natural product, and S (2), dimeric structure in series. The formation 1 2 is thought occur via reaction G with a nitrogen source, where nitrile carbon derived terpenoid skeleton.

10.1021/acs.jnatprod.7b00960 article EN Journal of Natural Products 2018-01-26

1,2-Dehydropyrrolizidine alkaloids are common toxic metabolites isolated from plants within the Boraginaceae, in particular genera Heliotropium and Echium. Previous studies have deduced structures of these often potent bioactives based upon mass spectrometric evidence, but identifications not established conclusive connectivity configurational data. Herein, we describe isolation full structural characterization echivulgarine, occurring pollen Echium vulgare correct structure previously...

10.1021/acs.jafc.5b02402 article EN Journal of Agricultural and Food Chemistry 2015-08-04
Coming Soon ...