Allan Patrick Macabeo

Allan Patrick Macabeo
University of Santo Tomas | UST · Department of Chemistry

Doctor of Science (Organic Chemistry)

About

121
Publications
40,340
Reads
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1,196
Citations
Introduction
Allan Patrick G. Macabeo was born in Ilocos Sur, Philippines. He received his BSc degree in chemistry in 1999 from the University of Santo Tomas. In 2011, he was awarded his Doctor of Natural Science in organic chemistry from the University of Regensburg (Bayern, Germany) under the supervision of Prof. Dr. Oliver Reiser. He undertook postdoctoral studies as an Alexander von Humboldt Fellow working with Prof. Dr. Marc Stadler at the Helmholtz Center for Infection Research, Braunschweig, Germany from 2017−2018. Prof. Macabeo has held an academic position at the University of Santo Tomas since 2001 and during this time has won a number of awards, including the Outstanding Young Scientist and TWAS awards in Chemistry in 2015. The Macabeo research group explores numerous interests within the scope of organic chemistry (e.g., medicinal chemistry, natural product isolation from medicinal plants and fungi, and drug development), utilizes computational chemical biology to probe and understand drug-biomolecule interactions, and makes new synthetic methodology concepts to facilitate construction of pharmaceutically relevant scaffolds (design of new synthetic transformations).
Additional affiliations
May 2017 - present
Helmholtz Centre for Infection Research
Position
  • Fellow
December 2015 - January 2016
Nagoya City University
Position
  • Fellow
June 2014 - present
University of Santo Tomas
Position
  • Professor (Associate)
Education
October 2007 - April 2011
Universität Regensburg
Field of study
  • Organic Chemistry

Publications

Publications (121)
Article
Full-text available
Laying the groundwork on preliminary structure–activity relationship study relating to the disruptive activity of cytochalasan derivatives on mammalian cell actin cytoskeleton, we furthered our study on the cytochalasans of the Dothideomycetes fungus, Sparticola triseptata. A new cytochalasan analog triseptatin (1), along with the previously descri...
Preprint
Breast cancer is the leading cause of cancer-related deaths among women. With the clinical success of several synthetic aromatase inhibitors (AIs) as therapeutic agents in post-menopausal estrogen receptor-positive breast cancer, natural products have been tapped in search of chemically diverse compounds with potential better effectiveness against...
Article
Full-text available
Since the efficiency in the transcription of the HIV genome contributes to the success of viral replication and infectivity, we investigated the downregulating effects of the spirobisindole alkaloids globospiramine (1), deoxyvobtusine (2), and vobtusine lactone (3) from the endemic Philippine medicinal plant, Voacanga globosa, during HIV gene trans...
Article
Full-text available
The global pandemic disease COVID-19 commands a number of host immunological responses to deadly cytokine-storm manifestations. Mitigation of incoming infectious comorbidities ushered by immunosuppression such as tuberculosis (TB) is warranted including the requirement of new drugs. Employment of computational screening methods and intricate select...
Article
Full-text available
Tuberculosis (TB) and cancer are among the maladies with high morbidity and mortality rates to date. This prompted the utilization of natural products in the discovery and development of new anti-TB and anticancer derivatives. In this study, we explored the antitubercular and antiproliferative activities of extracts and tetrahydrobisbenzylisoquinol...
Preprint
Full-text available
The novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) emerged in December 2019 leading to a global pandemic and lockdowns in different countries including the Philippines. There is an oral antiviral treatment, Paxlovid, produced by Pfizer that is currently authorized for emergency use to treat COVID-19. However, there is still a nece...
Preprint
Full-text available
Hyperreactive inflammatory response occurs when there is excessive activation of NF-κB leading to a pathologic cascade of inflammatory reactions. Thus, we investigated the inflammatory modulating potentials of the Philippine medicinal endemic plant Uvaria alba. ELISA was initially performed to measure levels of proinflammatory mediators (NO and PGE...
Article
Full-text available
The unprecedented global health threat of SARS-CoV-2 has sparked a continued interest in discovering novel anti-COVID-19 agents. To this end, we present here a computer-based protocol for identifying potential compounds targeting RNA-dependent RNA polymerase (RdRp). Starting from our previous study wherein, using a virtual screening campaign, we id...
Preprint
Full-text available
The unprecedented global health threat of SARS-CoV-2 has sparked a continued interest to discover novel anti-COVID-19 agents. To this end, we present here a computer-based protocol for identifying potential compounds targeting RNA-dependent RNA polymerase (RdRp). Starting from our previous study in which, by a virtual screening campaign, we identif...
Article
Full-text available
Axenic fermentation on solid rice of the saprobic fungus Sparticola junci afforded two new highly oxidized naphthalenoid polyketide derivatives, sparticatechol A (1) and sparticolin H (2) along with sparticolin A (3). The structures of 1 and 2 were elucidated on the basis of their NMR and HR-ESIMS spectroscopic data. Assignment of absolute configur...
Article
The ongoing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has been proven to be more severe than the previous coronavirus outbreaks due to the virus’ high transmissibility. With the emergence of new variants, this global phenomenon took on a more dramatic turn with many countries recently experiencing higher surges of confir...
Article
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A short, asymmetric synthesis of tetrahydro-2H-furo[3,2-b]pyrrole derivatives and (−)-Geissman–Waiss lactone starting from meso-cyclohexadiene epoxide is described. Pivotal transformations in the developed synthetic procedure include asymmetric epoxide ring opening to install the requisite 1S,5S stereocenters and oxidative lactonization/lactamizati...
Article
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The phenolic natural product magnolol exhibits neuroprotective properties through β-amyloid toxicity in PC-12 cells and ameliorative effects against cognitive deficits in a TgCRND8 transgenic mice model. Its bioavailability and blood–brain barrier crossing ability have been significantly improved using the metal–organic framework (MOF) UiO-66(Zr) a...
Article
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In this paper, we review the effects of large-scale neonicotinoid contaminations in the aquatic environment on non-target aquatic invertebrate and vertebrate species. These aquatic species are the fauna widely exposed to environmental changes and chemical accumulation in bodies of water. Neonicotinoids are insecticides that target the nicotinic typ...
Article
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The severity of the COVID-19 pandemic has necessitated the search for drugs against SARS-CoV-2. In this study, we explored via in silico approaches myxobacterial secondary metabolites against various receptor-binding regions of SARS-CoV-2 spike which are responsible in recognition and attachment to host cell receptors mechanisms, namely ACE2, GRP78...
Article
Full-text available
The use of chemicals to boost food production increases as human consumption also increases. The insectidal, nematicidal and acaricidal chemical carbofuran (CAF), is among the highly toxic carbamate pesticide used today. Alongside, copper oxide nanoparticles (CuO) are also used as pesticides due to their broad-spectrum antimicrobial activity. The o...
Article
Full-text available
Background: Accessing COVID-19 vaccines is a challenge despite successful clinical trials. This burdens the COVID-19 treatment gap, thereby requiring accelerated discovery of anti-SARS-CoV-2 agents. This study explored the potential of anti-HIV reverse transcriptase (RT) phytochemicals as inhibitors of SARS-CoV-2 non-structural proteins (nsps) by...
Article
Sparticols A (1) and B (2), two catechol-bearing naphthalenedioxy derivatives, were isolated from the submerged culture of the Spanish broom inhabiting Dothideomycetes fungus, Sparticola junci. The structures of 1 and 2 were established by NMR spectroscopic analysis and high-resolution mass spectrometry. The 8S absolute configuration of their β-hyd...
Article
Full-text available
Artificial sweeteners are widely used food ingredients in beverages and drinks to lower calorie intake which in turn helps prevent lifestyle diseases such as obesity. However, as their popularity has increased, the release of artificial sweetener to the aquatic environment has also increased at a tremendous rate. Thus, our study aims to systematica...
Article
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This mini-review is dedicated to the summary of results of the EU-funded Project “Golden Mycological Triangle” (acronym GoMyTri), which was carried out in collaboration of three research infrastructures in Germany, the Netherlands and Thailand during the years 2014-2018. The cooperation explored the mycological and microbiological biodiversity of E...
Article
Full-text available
Purpose: The purpose of this study was to evaluate the intraocular pressure (IOP) reduction efficiency of hyaluronic acid-chitosan-latanoprost link nanoparticle (HA-CS-latanoprost link NP) formulated eye drops. Methods: The IOP reduction study was performed in 24 normotensive albino rabbits. The test animals were randomized and grouped according...
Article
Inhibition of the major cyclic adenosine monophosphate-metabolizing enzyme PDE4 has shown potential for the discovery of drugs for cancer, inflammation, and neurodegenerative disorders such as Alzheimer’s disease. As a springboard to explore new anti-cancer and anti-Alzheimer’s chemical prototypes from rare Annonaceae species, the present study eva...
Article
Full-text available
Inhibition of the major cyclic adenosine monophosphate-metabolizing enzyme PDE4 has shown potential for the discovery of drugs for cancer, inflammation, and neurodegenerative disorders such as Alzheimer’s disease. As a springboard to explore new anti-cancer and anti-Alzheimer’s chemical prototypes from rare Annonaceae species, the present study eva...
Article
Full-text available
As a nicotinoid neurotoxic insecticide, imidacloprid (IMI) works by disrupting nerve transmission via nicotinic acetylcholine receptor (nAChR). Although IMI is specifically targeting insects, nontarget animals such as the freshwater shrimp, Neocaridina denticulata, could also be affected, thus causing adverse effects on the aquatic environment. To...
Article
Full-text available
Citation: Magpantay, H.D.; Malaluan, I.N.; Manzano, J.A.H.; Quimque, M.T.; Pueblos, K.R.; Moor, N.; Budde, S.; Bangcaya, P.S.; Lim-Valle, D.; Dahse, H.-M.; et al. Antibacterial and COX-2 Inhibitory Tetrahydrobisbenzylisoquinoline Alkaloids from the Philippine Medicinal Plant Phaeanthus ophthalmicus. Plants 2021, 10, 462.
Preprint
Full-text available
Background: Accessing COVID-19 vaccines is a challenge despite successful clinical trials. This burdens the COVID-19 treatment gap, thereby requiring accelerated discovery of anti-SARS-CoV-2 agents. Thus, this study explored the potential of anti-HIV reverse transcriptase (RT) phytochemicals as inhibitors of SARS-CoV-2 non-structural proteins (nsps...
Preprint
p>Background: Accessing COVID-19 vaccines is a challenge despite successful clinical trials. This burdens the COVID-19 treatment gap, thereby requiring accelerated discovery of anti-SARS-CoV-2 agents. Thus, this study explored the potential of anti-HIV reverse transcriptase (RT) phytochemicals as inhibitors of SARS-CoV-2 non-structural proteins (ns...
Preprint
Full-text available
The severity of the COVID-19 pandemic necessitated the search for drugs against the causative viral agent, SARS-CoV-2. Among the promising targets is the viral surface of SARS-CoV-2 adorned by spike proteins appearing as crown-like structures known for their function in viral attachment and entry mechanisms. To exploit the potential of previously r...
Preprint
The severity of the COVID-19 pandemic necessitated the search for drugs against the causative viral agent, SARS-CoV-2. Among the promising targets is the viral surface of SARS-CoV-2 adorned by spike proteins appearing as crown-like structures known for their function in viral attachment and entry mechanisms. To exploit the potential of previously r...
Preprint
Full-text available
Artificial sweeteners are widely used food ingredients in beverages and drinks to lower calorie intake which in turn prevent lifestyle diseases such as obesity. Epidemiological evidences suggest that an overdose of artificial sweeteners could result to adverse effects after consumption. Thus, our study aims to systematically explore the potential a...
Preprint
div>Aims: To evaluate the in vitro antiproliferative, anticholinesterase and anti-phosphodiesterase activities of the sub-extracts of Uvaria alba (family Annonaceae) and explore putative binding mechanisms of its chemical constituents in silico. Main methods: U. alba sub-extracts, obtained by solvent-solvent partition, were subjected to antiproli...
Article
Full-text available
The novel coronavirus SARS-CoV2, the causative agent of the pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide necessitated the discovery of new substances for anti-COVID-...
Article
Full-text available
Bioavailability plays an important role in drug activity in the human body, as certain drug amounts should be present to elicit activity. However, low bioavailability of drugs leads to negligible use for human benefit. In this study, the diversely active neolignan, magnolol, was impregnated onto a Zr-based organometallic framework [Uio-66(Zr)] to i...
Preprint
Full-text available
The novel coronavirus SARS-CoV2, the causative agent of the worldwide pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide have necessitated the need to discover substances...
Preprint
The novel coronavirus SARS-CoV2, the causative agent of the worldwide pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide have necessitated the need to discover substances...
Article
Full-text available
Pseudopalawania siamensis gen. et sp. nov., from northern Thailand, is introduced based on multi-gene analyses and morphological comparison. An isolate was fermented in yeast malt culture broth and explored for its secondary metabolite production. Chromatographic purification of the crude ethyl acetate (broth) extract yielded four tetrahydroxanthon...
Article
Chromatographic purification of the DCM sub-extract of Uvaria grandiflora led to the isolation and characterization of a new polyoxygenated cyclohexane derivative, grandifloranol (1), together with five known compounds. Among the compounds isolated, zeylenone (3) showed moderate antitubercular activity against Mycobacterium tuberculosis H37Rv with...
Article
Full-text available
The alpha-glucosidase-and lipase-inhibitory activities of three phenalenones (1-3) and one phenylpropanoid (4) from the ethyl acetate extracts of a Pseudolophiostoma sp. are described. They represent the first secondary metabolites reported from the genus Pseudolophiostoma. Scleroderolide (1) and sclerodione (2) exhibited potent alpha-glucosidase-a...
Article
Two new -pyrone derivatives, udagawanones A (1) and B (2), along with the known compounds (Z)-4-hydroxy-3-(3-hydroxy-3-methylbut-1-en-1-yl)benzoic acid (3), isosclerone (4), cyclo-(L-Leu-L-Pro) (5), and cyclo-(L-Pro-L-Tyr) (6), were isolated from cultures of the endophyte Neurospora udagawae. Their structures were elucidated by extensive spectrosc...
Article
To explore the chemical diversity of metabolites from new species of Dothideomycetes, the ex-type strain of Sparticola junci was investigated. Seven highly oxygenated and functionalized spirodioxynaphthalene natural products incorporating carboxyalkylidene-cyclopentanoid (1-4), carboxyl-functionalized oxabicyclo[3.3.0]octane (5-6), and annelated 2-...
Article
Full-text available
Background: Infection with Mycobacterium tuberculosis, the causative agent of TB, is responsible for one of the global epidemics. Thus, new drugs are needed that do not confer cross-resistance with the currently administered front-line therapeutics. Quinoline-based natural products and synthetic derivatives have been extensively explored for antitu...
Article
Full-text available
Endophytic fungi are less explored in terms of their pharmacological applications, thus screening their phytochemical constituents and biological activities is of interest. In this study, the endophytic fungi Nigrospora and Colletotrichum spp. were isolated from the leaves of Uvaria grandiflora. The identity of the endophytes was established by mol...
Article
Background Electrophilic compounds bearing Michael acceptors present great promise in anticancer drug discovery. Methods Drawing inspirations from cytotoxic Piper lactam alkaloids, twelve N-acylated butyro- and valerolactams were prepared and evaluated for antiproliferative and cytotoxic activities against the normal human umbilical vein endotheli...
Article
Full-text available
Fungi are an understudied, biotechnologically valuable group of organisms. Due to the immense range of habitats that fungi inhabit, and the consequent need to compete against a diverse array of other fungi, bacteria, and animals, fungi have developed numerous survival mechanisms. The unique attributes of fungi thus herald great promise for their ap...
Article
Full-text available
Numerous gatherings of a new species of the genus Gibellula, closely resembling the monotypic, neotropical G. mirabilis were encountered in Thailand. The taxon was cultured successfully although no in vitro sporulation was observed. The new species, Gibellula gamsii, could be distinguished from closely related other Gibellula species on the basis o...
Article
Full-text available
The methanolic extract of Callyspongia samarensis (MCS) significantly inhibited β-secretase 1 (IC50 99.82 µg/mL) in a dose-dependent manner and demonstrated a noncompetitive type of inhibition. Furthermore, it exhibited the highest AMPK activation (EC50 14.47 μg/mL) as compared with the standard, Aspirin (EC50 >100 μg/mL). HPLC/ESI-MS analysis of M...
Presentation
Syzygium lineatum or “lubeg” is a popular nutraceutical plant in the Apayao region known for its traditional antioxidant and cancer-healing properties. In this study, a bioassay-guided approach was undertaken to investigate the anti-cancer principles from lubeg. Thus, crude extraction of the air-dried leaves followed by fractionation afforded three...
Article
Full-text available
Roussoella species are well recorded from both monocotyledons and dicotyledons. As part of a research program to discover biologically active compounds from plant-associated Dothideomycetes in Thailand, the strain Roussoella sp. (MFLUCC 17-2059), which represents an undescribed species, was isolated from Clematis subumbellata Kurz, fermented in yea...
Article
Two new chlorine-containing polyoxygenated seco-cyclohexenes, albanols A (1) and B (2), along with the oxepinone metabolite grandiuvarone (3) were isolated from the endemic Philippine Annonaceae plant Uvaria alba. Both new compounds exhibited modest antitubercular activity. Compound 1 showed cytostatic activity (ranging from 1-50 μM) against HeLa c...
Article
Full-text available
This synthetic work reports a concise, asymmetric synthesis of b -amino- g -butyrolactone acetic acid – D-leucine hybrid 1 which will serve as model starting template sub-unit for preparing a/g foldameric oligopeptides containing unnatural g -amino acid residues. The synthesis of cis-substituted 1 was successfully achieved in six linear steps with...
Article
Phytochemical study on the Philippine endemic Annonaceae plant Uvaria valderramensis afforded a new highly oxygenated seco-cyclohexene derivative, valderepoxide (1), along with the six known compounds uvamalols D (2) and G (3), grandiuvarone (4), 2′-hydroxy-3′,4′,6′-trimethoxychalcone (5), valderramenol B (6) and benzoic acid. The structure of 1 wa...
Article
Phthalates are the most common form of plasticizers. Due to the ease with which phthalates diffuse from their plastics and the sheer volume of plastics that have been introduced to the environment, they represent one of the most ubiquitous and persistent chemicals known. Phthalates are known to have several toxic effects. The study was carried out...
Article
Full-text available
Different derivatives based on the betulinic acid triterpenoidal scaffold were synthesized and characterized spectroscopically. The derivatives including synthetic intermediates were evaluated for their cytotoxic activity against the human colorectal carcinoma cell line (HCT116) using a colorimetric sulforhodamine assay (SRB). Among the synthesized...
Article
Phthalates are the most common form of plasticizers. Due to the ease with which phthalates diffuse from their plastics and the sheer volume of plastics that have been introduced to the environment, they represent one of the most ubiquitous and persistent chemicals known. Phthalates are known to have several toxic effects. The study was carried out...
Article
Full-text available
Among the known organocatalyst manifolds, the organocatalytic utility of 2- pyridylimidazolines has been less explored. In this study, a collection of chiral 2-pyridyl-2-imidazolines (picolinylimidazolines) were screened for organocatalytic activity towards enantioselective direct Aldol reaction. The chiral imidazolines (1a-1d) were prepared throug...