Publications by authors named "Niamh O'Boyle"

Background: Limonene and linalool are used in cosmetic products for their floral scents, but their oxidation products are strong contact allergens whose mechanisms of action are still not fully understood.

Objectives: The effects of limonene hydroperoxide (Lim-2-OOH) and linalool hydroperoxides (Lin-6/7-OOH) on the lipid profile of a human keratinocyte cell line (HaCaT) were evaluated. 2,4-Dinitrofluorobenzene (DNFB) was also included.

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Chronic lymphocytic leukemia (CLL) is a malignancy of mature B cells, and it is the most frequent form of leukemia diagnosed in Western countries. It is characterized by the proliferation and accumulation of neoplastic B lymphocytes in the blood, lymph nodes, bone marrow and spleen. We report the synthesis and antiproliferative effects of a series of novel ethanoanthracene compounds in CLL cell lines.

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Biocatalysis is a valuable industrial approach in active pharmaceutical ingredient (API) manufacturing for asymmetric induction and synthesis of chiral APIs. Herein, we investigated synthesis of a panel of microtubule-destabilising antiproliferative β-lactam enantiomers employing a commercially available immobilised Candida antarctica lipase B enzyme together with methanol and MTBE. The β-lactam ring remained intact during chiral kinetic resolution reactions, plausibly due to a bulky N-1 phenyl substituent on the β-lactam ring substrate.

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Background: Cinnamic alcohol is a natural compound, widely used in fragrances, which can cause allergic contact dermatitis. Cinnamic alcohol lacks intrinsic reactivity and autoxidation or metabolic activation is necessary for it to act as a sensitizer.

Methods: Bioactivation of cinnamic alcohol was explored using human liver microsomes, human liver S9 and SkinEthic™ Reconstructed Human Epidermis.

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Many drugs are chiral with their chirality determining their biological interactions, safety, and efficacy. Since the 1980s, there has been a regulatory preference to bring single enantiomer to market. This perspective discusses trends related to chirality that have developed in the past decade (2013-2022) of new drug approvals.

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Chronic lymphocytic leukaemia (CLL) is a malignancy of the immune B lymphocyte cells and is the most common leukaemia diagnosed in developed countries. In this paper, we report the synthesis and antiproliferative effects of a series of ()-9-(2-nitrovinyl)anthracenes and related nitrostyrene compounds in CLL cell lines and also in Burkitt's lymphoma (BL) cell lines, a rare form of non-Hodgkin's immune B-cell lymphoma. The nitrostyrene scaffold was identified as a lead structure for the development of effective compounds targeting BL and CLL.

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The synthesis and biochemical activity of a series of chiral trans 3-hydroxyl β-lactams targeting tubulin is described. Synthesis of the series of enantiopure β-lactams was achieved using chiral derivatising reagent N-Boc-l-proline. The absolute configuration was determined as 3S,4S for (+) enantiomer 4EN1 and 3R,4R for (-) enantiomer 4EN2.

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A series of novel 3-(prop-1-en-2-yl)azetidin-2-one, 3-allylazetidin-2-one and 3-(buta-1,3-dien-1-yl)azetidin-2-one analogues of combretastatin A-4 (CA-4) were designed and synthesised as colchicine-binding site inhibitors (CBSI) in which the ethylene bridge of CA-4 was replaced with a β-lactam (2-azetidinone) scaffold. These compounds, together with related prodrugs, were evaluated for their antiproliferative activity, cell cycle effects and ability to inhibit tubulin assembly. The compounds demonstrated significant in vitro antiproliferative activities in MCF-7 breast cancer cells, particularly for compounds and , with IC values in the range 10-33 nM.

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The Group for the Promotion of Pharmaceutical Chemistry in Academia (GPA) held their 30th annual conference in August 2022 in Trinity College Dublin, Ireland. There were 9 keynote presentations, 10 early career researcher presentations and 41 poster presentations.

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The stilbene combretastatin A-4 (CA-4) is a potent microtubule-disrupting agent interacting at the colchicine-binding site of tubulin. In the present work, the synthesis, characterisation and mechanism of action of a series of 3-fluoro and 3,3-difluoro substituted β-lactams as analogues of the tubulin-targeting agent CA-4 are described. The synthesis was achieved by a convenient microwave-assisted Reformatsky reaction and is the first report of 3-fluoro and 3,3-difluoro β-lactams as CA-4 analogues.

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Lipids are an important constituent of skin and are known to be modified in many skin diseases including psoriasis and atopic dermatitis. The direct effects of common metallic contact allergens on the lipid composition of skin has never been investigated, to the best of our knowledge. We describe skin lipid profiles in the stratum corneum and viable epidermis of human skin from a female donor upon exposure to three metal allergens (nickel, cobalt and chromium) visualised using time-of-flight secondary ion mass spectrometry (ToF-SIMS), which allows for simultaneous visualisation of both the allergen and skin components such as lipids.

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Trans-β-lactam isomers have garnered much attention as anti-cancer microtubule targeting agents. Currently available synthetic methods are available for the preparation of enantiopure β-lactams and favour isomeric cis/trans β-lactam mixtures. Indirect chiral resolution offers the opportunity for isolation of exclusively enantiopure trans-β-lactams.

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We describe a novel nature-derived epoxy resin monomer (ERM) derived from the plant lignan pinoresinol. Epoxy resins are thermosetting materials in global usage owing to their excellent technical properties such as flexibility and durability. However, their adverse health effects are often not considered and affect users of epoxy resins worldwide.

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This Special Issue of is devoted to significant advances achieved in the field of Anticancer Drugs in 2021 [...

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The 29th Annual GPA (Group for the Promotion of Pharmaceutical chemistry in Academia) Conference was a virtual event this year due to the COVID-19 pandemic and spanned three days from Wednesday 25 to Friday 27 August 2021. The meeting brought together an international delegation of researchers with interests in medicinal chemistry and interfacing disciplines. Abstracts of keynote lectures given by the 10 invited speakers, along with those of the 8 young researcher talks and the 50 flash presentation posters, are included in this report.

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Antimitotic drugs that target tubulin are among the most widely used chemotherapeutic agents; however, the development of multidrug resistance has limited their clinical activity. We report the synthesis and biological properties of a series of novel 3-chloro-β-lactams and 3,3-dichloro-β-lactams (2-azetidinones) that are structurally related to the tubulin polymerisation inhibitor and vascular targeting agent, Combretastatin A-4. These compounds were evaluated as potential tubulin polymerisation inhibitors and for their antiproliferative effects in breast cancer cells.

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We report the synthesis and biochemical evaluation of compounds that are designed as hybrids of the microtubule targeting benzophenone phenstatin and the aromatase inhibitor letrozole. A preliminary screening in estrogen receptor (ER)-positive MCF-7 breast cancer cells identified 5-((2-1,2,3-triazol-1-yl)(3,4,5-trimethoxyphenyl)methyl)-2-methoxyphenol as a potent antiproliferative compound with an IC value of 52 nM in MCF-7 breast cancer cells (ER+/PR+) and 74 nM in triple-negative MDA-MB-231 breast cancer cells. The compounds demonstrated significant G/M phase cell cycle arrest and induction of apoptosis in the MCF-7 cell line, inhibited tubulin polymerisation, and were selective for cancer cells when evaluated in non-tumorigenic MCF-10A breast cells.

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Our skin is the interface between us and our environment - a flexible barrier that has evolved for protection, immunity, regulation and sensation. Once regarded as inert, we now know that it is a dynamic environment. Skin lipids are crucial to the structure and function of skin.

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A novel series of quinoline derivatives of combretastatin A-4 incorporating rigid hydrazone and a cyclic oxadiazole linkers were synthesized and have demonstrated potent tubulin polymerization inhibitory properties. Many of these novel derivatives have shown significant antiproliferative activities in the submicromolar range. The most potent compound, , demonstrated superior IC values ranging from 0.

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A series of related substituted 1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-ones have been characterized: 3-(4-fluoro-phen-yl)-4-(4-meth-oxy-phen-yl)-1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-one, CHFNO (), 3-(furan-2-yl)-4-(4-meth-oxy-phen-yl)-1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-one, CHNO (), 4-(4-meth-oxyphen-yl)-3-(naphthalen-1-yl)-1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-one, CHNO (), 3-(3,4-di-meth-oxy-phen-yl)-4-(4-meth-oxy-phen-yl)-1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-one, CHNO () and 4,4-bis-(4-meth-oxy-phen-yl)-3-phenyl-1-(3,4,5-tri-meth-oxy-phen-yl)azetidin-2-one, CHNO (). All of the compounds are racemic. The lactam and 3,4,5-tri-meth-oxy-phenyl rings are approximately co-planar and the orientation of the lactam and the 4-meth-oxy-phenyl substituent is approximately orthogonal.

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4-Aryl-4H-Chromene derivatives have been previously shown to exhibit anti-proliferative, apoptotic and anti-angiogenic activity in a variety of tumor models in vitro and in vivo generally via activation of caspases through inhibition of tubulin polymerisation. We have previously identified by Virtual Screening (VS) a 4-aryl-4H-chromene scaffold, of which two examples were shown to bind Estrogen Receptor α and β with low nanomolar affinity and <20-fold selectivity for α over β and low micromolar anti-proliferative activity in the MCF-7 cell line. Thus, using the 4-aryl-4H-chromene scaffold as a starting point, a series of compounds with a range of basic arylethers at C-4 and modifications at the C3-ester substituent of the benzopyran ring were synthesised, producing some potent ER antagonists in the MCF-7 cell line which were highly selective for ERα (compound 35; 350-fold selectivity) or ERβ (compound 42; 170-fold selectivity).

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A series of novel 1,4-diaryl-2-azetidinone analogues of combretastatin A-4 (CA-4) have been designed, synthesised and evaluated in vitro for antiproliferative activity, antiapoptotic activity and inhibition of tubulin polymerisation. Glucuronidation of CA-4 by uridine 5-diphosphoglucuronosyl transferase enzymes (UGTs) has been identified as a mechanism of resistance in cancer cells. Potential sites of ring B glucuronate conjugation are removed by replacing the B ring meta-hydroxy substituent of selected series of β-lactams with alternative substituents e.

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It is over 50 years since the discovery of microtubules, and they have become one of the most important drug targets for anti-cancer therapies. Microtubules are predominantly composed of the protein tubulin, which contains a number of different binding sites for small-molecule drugs. There is continued interest in drug development for compounds targeting the colchicine-binding site of tubulin, termed colchicine-binding site inhibitors (CBSIs).

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Special Issue "Anticancer Drugs".

Pharmaceuticals (Basel)

September 2019

The focus of this Special Issue of is on the design, synthesis, and molecular mechanism of action of novel antitumor, drugs with a special emphasis on the relationship between the chemical structure and the biological activity of the molecules. This Special Issue also provides an understanding of the biologic and genotypic context in which targets are selected for oncology drug discovery, thus providing a rationalization for the biological activity of these drugs and guiding the design of more effective agents. In this Special Issue of dedicated to anticancer drugs, we present a selection of preclinical research papers including both traditional chemotherapeutic agents and newer more targeted therapies and biological agents.

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