Ana Lourenço

Ana Lourenço
Universidade NOVA de Lisboa | NOVA · Department of Chemistry

Assistant Professor

About

41
Publications
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781
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Publications

Publications (41)
Article
Full-text available
A novel approach has been developed for the efficient synthesis of the unsymmetrical (2-aminopyrrolidin-1-yl)carboxamidine alkaloidal core found in Cernumidine ( 1 ) and its analogs ( 20a , 20c , 20f , 20i-o ). The key transformation...
Conference Paper
Full-text available
Once more under the auspices of the Sociedade Portuguesa de Química, two important fields of Chemistry are brought together into a single event, the 14th National Organic Chemistry Meeting and the 7th National Medicinal Chemistry Meeting. These conferences brought together both long-recognized experts and newcomers.
Article
Full-text available
Invasive species are currently a world menace to the environment, although the study of their chemistry may provide a means for their future beneficial use. From a study of Portuguese Acacia melanoxylon R. Br. five known compounds were isolated: lupeol, 3β-Z-coumaroyl lupeol, 3β-E-coumaroyl lupeol (dioslupecin A), kolavic acid 15-methyl ester and v...
Chapter
This chapter focuses on nitrogen heterocyclic compounds and describes synthetic routes in which a stereoselective aza‐Diels–Alder reaction represents the most suitable strategy for constructing chiral aza‐heterocyclic motifs. It illustrates the approaches using the asymmetric aza‐Diels–Alder reaction for the construction of natural products. The ch...
Article
Full-text available
Granulated cork was submitted to subcritical water extraction/hydrolysis in a semi-continuous reactor at temperatures in the range of 120–200 °C and with a constant pressure of 100 bar. The influence of temperature on the composition of the cork extracts obtained was assessed—namely, their content of carbohydrates and phenolics. The extraction yiel...
Article
Full-text available
In this review, a brief description of the invasive phenomena associated with plants and its consequences to the ecosystem is presented. Five worldwide invasive plants that are a threat to Portugal were selected as an example, and a brief description of each is presented. A full description of their secondary metabolites and biological activity is...
Article
Full-text available
The synthesis of an unreported 2-aminopyrrolidine-1-carboxamidine unit is here described for the first time. This unusual and promising structure was attained through the oxidative decarboxylation of amino acids using the pair of reagents, silver(I)/peroxydisulfate (Ag(I)/S2O82-) followed by intermolecular (in the case of l-proline derivative) and...
Article
Full-text available
Sesterterpenes form a small group of terpenoids that are mainly present in the marine world although they are also produced by terrestrial organisms such as fungi, and in minor extent higher plants, lichens and insects. Sesterterpenes are diverse and these compounds display significant biological activities such as anti-inflammatory, cytotoxic, ant...
Article
Full-text available
Tofacitinib is a Janus activated kinase (JAK) inhibitor approved for the treatment of rheumatoid arthritis and active psoriatic arthritis. Its synthesis normally involves long synthetic sequences due to the chirality associated to the piperidine ring. This review is a comprehensive analysis of the different synthetic methods used to prepare this ac...
Article
Full-text available
In this review a brief description of the invasive phenomena associated with algae and its consequences on the ecosystem are presented. Three examples of invasive algae of Southern Europe, belonging to Rodophyta, Chlorophyta, and Phaeophyta, were selected, and a brief description of each genus is presented. A full description of their secondary met...
Article
An efficient solid-phase synthesis approach is here reported for the first time to prepare the EGFR inhibitor Gefitinib. The five-step synthetic strategy used FMP resin as the solid support, and FTIR and colorimetric assays were used to track the reaction’s progress. Gefitinib was obtained with an overall yield of 40%.
Article
(R)‐Metacycloprodigiosin can exist in three different tautomeric forms, each with hydrogens at C9′ and C12 in syn or anti orientation. With the addition of HCl, this structural diversity reduces to syn‐(R)‐metacycloprodigiosin‐HCl (1a) and anti‐(R)‐metacycloprodigiosin‐HCl (1b), each with multiple conformers. Energetics and chiroptical properties,...
Conference Paper
In the last two decades, it has been observed an increasing low enrolment of students in chemistry teaching courses in secondary schools. On the one hand, because of the a negative connotation of chemistry, associated with the potentially toxic and pollutant chemical industry, and on the other hand, that the teaching of this subject is exclusively...
Article
This work was conducted to identify the major low molecular weight compounds present in the wine precipitate and to assess their potential contribution to wine protein haze formation. The heat-induced protein precipitate from a white Moscatel of Alexandria wine was subjected to alkaline hydrolysis. The major compound present was found to be caffeic...
Article
Full-text available
A comprehensive review on the chemistry of Spongia sp. is here presented, together with the biological activity of the isolated compounds. The compounds are grouped in sesquiterpene quinones, diterpenes, C21 and other linear furanoterpenes, sesterterpenes, sterols (including secosterols), macrolides and miscellaneous compounds. Among other reports...
Article
Analysis of the calculated and measured optical rotation (OR) together with other calculated chiroptical properties such as electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) of the prodigiosin alkaloid streptorubin B shows that these are dominated by the pseudoenantiomeric atropisomers anti-(S)-streptorubin B (1A) and syn...
Article
Full-text available
Grapevine is one of the most cultivated fruit crop worldwide with Vitis vinifera being the species with the highest economical importance. Being highly susceptible to fungal pathogens and increasingly affected by environmental factors, it has become an important agricultural research area, where gene expression analysis plays a fundamental role. Qu...
Article
Full-text available
A new naturally occurring isoflavone, derrone, was isolated from Ulex jussiaei (Leguminosae) together with the isoflavones ulexins A-C, lupalbigenin, isolupalbigenin, 7-O-methylso-lupalbigenin, isoderrone, ulexone A and isochandalone, the pterocarpans (6aR,11aR)-(-)-maackiain, (6aR,11aR)-(-)-2-methoxymaackiain and (6aR,11aR)-(-)-4-methoxymaackiain,...
Article
Full-text available
Triterpenoids with 31-norcycloartanone structure were isolated for the first time from the Solanum genus. Cycloeucalenone and 24-oxo-31-norcycloartanone were the main constituents of the dichloromethane extract of Solanum cernuum Vell. leaves [7% (w/w) and 1.47% (w/w)]. Both triterpenoids were tested against human tumour cell lines, and 24-oxo-31-n...
Article
Full-text available
Nine flavonoids have been isolated from Ulex jussiaei and U. minor (Leguminosae). From both species the isoflavonoids ulexin A and the new naturally occurring ulexin B have been identified, together with isoderrone, the pterocarpans (-)-maackiain and (-)-4-methoxymaackiain, and the chalcone isobavachromene. The pterocarpan (-)-2-methoxymaackiain wa...
Article
Full-text available
(-)-Agelasidine A was identified from the methanol extract of the marine sponge Agelas clathrodes for the first time together with zooanemonin, 1-carboxymethylnicotinic acid, hymenidin, mukanadins A and C, monobromodispacamide, agelasidine D, 2-amide-4-bromopyrrole, O-methyltryptophan and an agelasines mixture. The structures were characterized by...
Article
Full-text available
Cycloeucalenone (1) and 24-oxo-31-norcycloartanone (2) obtained from Solanum cernuum Vell. were assayed to explore their pharmacologic roles. Previous studies showed that (2) has selective activity against lung tumor cell line (NCIH460) which expresses high levels of COX-2, suggesting its role in inflammatory process, and also a link between chroni...
Article
Full-text available
The cytotoxicity-guided study of the dichloromethane and ethanol extracts of Thymus mastichina L. using the HCT colon cancer cell line allowed the identification of nine compounds, sakuranetin (1), sterubin (2), oleanolic acid (3), ursolic acid (4), lutein (5), beta-sitosterol (6), rosmarinic acid (7), 6-hydroxyluteolin-7-O-beta-glucopyranoside (8)...
Article
Full-text available
The development of new drugs that can be valuable for the evolution of diseases' treatment is a goal for different areas of research, namely natural products chemistry, molecular biology and biochemistry, pharmacology, medicinal chemistry, synthetic organic chemistry and analytical chemistry. Nature is the main source of compounds for pharmaceutica...
Article
Cernumidine and isocernumidine were identified in the ethanol extract of the leaves of Solanum cernuum Vell. together with four known phenolic compounds. The alkaloids have a natural (2-aminopyrrolidin-1-yl)carboxamidine alkaloidal base acylated with isoferulic (3-hydroxy-4-methoxycinnamic) acid with Z and E configurations, respectively. The struct...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
A study of the 1H and 13C NMR, spectra, variation of the molecular rotations and behavior in the CD exciton chirality method of several C-12 epimers of 12-hydroxy-, 12-acetory- and 12-benzoyloxy-neo-clerodane derivatives has been achieved, providing useful alternative methods for establishing the C-12 absolute configuration of this kind of compound...
Article
A direct process for the recovery of the alkaloid lupanine from the debittering wastewaters of Lupinus albus L. was studied. The wastewaters were 10-fold concentrated by a membrane process, osmotic evaporation, using a calcium chloride solution as the osmotic agent. The concentrated effluent was treated in a basic solid medium and extracted with et...
Article
Full-text available
Six species of Portuguese Ulex L. in a total of nineteen populations were studied by GC-EIMS as to their content in quinolizidine alkaloids. Sparteine, beta-isosparteine, jussiaeiine A, N-methylcytisine, cytisine, 5,6-dehydrolupanine, rhombifoline, lupanine, jussiaeiine B, N-formylcytisine, N-acetylcytisine, anagyrine, jussiaeiine C, jussiaeiine D,...
Article
A new enantioselective/inverse phase transfer catalysis (IPTC) reaction for the Markovnikov hydration of double bounds by an oxymercuration–demercuration reaction with cyclodextrins as catalysts was disclosed. Moderate ee (up to 32%) and yields (14–60%) were obtained for allylic amines and protected allylic alcohols as starting materials.
Article
A review of the structural identification and bioactivity of simple indolizidine and quinolizidine alkaloids isolated from amphibians, ants,fungi, plants and marine sources, covering the period from 1994 to 1999,is herein presented. Some of the new alkaloids do not have complete structural assignments due to the minute amounts that were isolated an...
Article
From the dichloromethane extract of Ulex airensis three new isoflavonoids, ulexin C (1), ulexin D (2), and 7-O-methylisolupalbigenin (3), were isolated and characterized by spectroscopic methods. Ulexin D (2) was also identified from the dichloromethane extract of Ulex europaeus ssp. europaeus. Together with these new metabolites, 18 compounds of p...
Article
From the dichloromethane extract of Ulex airensis three new isoflavonoids, ulexin C (1), ulexin D (2), and 7-O-methylisolupalbigenin (3), were isolated and characterized by spectroscopic methods. Ulexin D (2) was also identified from the dichloromethane extract of Ulex europaeus ssp. europaeus. Together with these new metabolites, 18 compounds of p...
Article
From an acidic extract of Ulex jussiaei four new quinolizidine alkaloids, jussiaeiines A (1), B (2), C (3), and D (4), were isolated and characterized by spectroscopic methods together with (-)-cytisine, (-)-N-methylcytisine, and (-)-anagyrine. The proposed biosynthetic origin of these new alkaloids is briefly discussed.
Article
From an acidic extract of Ulex-jussiaei four new quinolizidine alkaloids, jussiaeiines A (1), B (2), C (3), and D (4), were isolated and characterized by spectroscopic methods together with (-)-cytisine, (-)-N-methylcytisine, and (-)-anagyrine. The proposed biosynthetic origin of these new alkaloids is briefly discussed.
Article
A new pterocarpan has been isolated from Ulex parviflorus. The structure of this compound, (−)-2,3,4-trimethoxy-8,9-methylenedioxypterocarpan, was established by spectroscopic means. In addition, the known pterocarpans, (−)-maackiain, (−)-4-methoxymaackiain, (−)-2-methoxymaackiain, the isoflavone isoderrone and the triterpenoid soyasapogenol B were...
Article
Two new ceramides were identified among the chemical constituents of the fungus Phellinus pini. The structures of these compounds, N-(2'-hydroxynonacosanoyl)-D-erythro-1,3,4-trihydroxy-2-amino-octadecane and N-(2'-hydroxytriacontanoyl)-D-erythro-1,3,4-trihydroxy-2-amino-octadecane, were established by spectroscopic and chemical means. In addition,...
Article
A study of the 1H and 13C NMR, spectra, variation of the molecular rotations and behavior in the CD exciton chirality method of several C-12 epimers of 12-hydroxy-, 12-acetory- and 12-benzoyloxy-neo-clerodane derivatives has been achieved, providing useful alternative methods for establishing the C-12 absolute configuration of this kind of compound...
Article
Four newneo-clerodane diterpenoids have been isolated from the aerial parts ofTeucrium gracile. The structures of these compounds, 3β,19-diacetoxy-4α,18;15,16-diepoxy-6β-hydroxy-neo-cleroda-13(16),14-dien-20,12Solide (teugracilin A), 19-acetoxy-4α,18;15,16-diepoxy-3β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,12S-olide (3-O-deacetylteugracilin A),...
Article
Starting from montanin A (3) compound 11 was obtained by opening of the C-20,C-12 γ-lactone (6), oxidation of the C-12 hydroxyl group (9), relactonization to the β,γ-unsaturated γ-lactone (10) via the C-12 enol form, and final selective air oxidation of the α,β,β′-trialkyl furan to the corresponding α,β-unsaturated γ-lactone (11). Compound 11 was i...
Article
The absolute configurations of four previously isolated clerodane diterpenoids, montanin C, 12-epiteupolin II, teugnaphalodin and teubutilin B, have been established by chemical correlation with some derivatives of 19-acetylgnaphalin, a neo-clerodane whose absolute stereochemistry is known. The above four compounds also belong to the neo-clerodane...

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