Fractioning of Proanthocyanidins of Uncaria tomentosa. Composition and Structure-Bioactivity Relationship

In a previous study, the detailed low-molecular weight polyphenolic profile of the different plant parts (leaves, stem, bark and wood) of Uncaria tomentosa was reported, the leaves being the plant part with the highest phenolic content and presenting the most heterogenous proanthocyanidin composition. Further, cytotoxicity of leaves extracts in two cancer cell lines was also found to be higher than in the remaining parts of the plant. In the present study, fractioning of U. tomentosa leaves polyphenolic extracts was performed using Diaion® HP-20 resin and a detailed characterization and quantification of fractions (n = 5) was achieved using advanced analytical techniques such as Ultra-Performance Liquid Chromatography coupled with Electrospray Ionization and Triple Quadrupole (TQD) Tandem Mass Spectrometry (UPLC/TQ-ESI-MS) and 13C-NMR. Oxygen Radical Absorbance Capacity (ORAC) and cytotoxicity on gastric adenocarcinoma AGS and colon adenocarcinoma SW20 cell lines were also determined in the different fractions. Results showed selective distribution of 32 non-flavonoid and flavonoid phenolics among the different fractions. ORAC varied between 3.2 and 11.8 µmol TE/mg in the different fractions, whereas IC50 of cytotoxicity on gastric adenocarcinoma AGS and colon adenocarcinoma SW20 cell lines best values were between 71.4 and 75.6 µg/mL. Fractions rich in proanthocyanidins also showed the highest bioactivity. In fact, significant positive correlation was found between total proanthocyanidins (TP) quantified by UPLC-DAD and ORAC (R 2 = 0.970), whereas significant negative correlation was found between TP and cytotoxicity towards AGS (R 2 = 0.820) and SW620 (R 2 = 0.843) adenocarcinoma cell lines. Among proanthocyanidins, propelargonidin dimers were of particular interest, showing significant correlation with cytotoxic selectivity on both gastric AGS (R 2 = 0.848) and colon SW620 (R 2 = 0.883) adenocarcinoma cell lines. These results show further evidence of the bioactivity of U. tomentosa proanthocyanidin extracts and their potential health effects.Agencia Española de Cooperación Internacional para el Desarrollo/[A/023397/09]/AECID/EspañaAgencia Española de Cooperación Internacional para el Desarrollo/[A/030037/10]/AECID/EspañaCosta Rica-USA Foundation/[]/CRUSA/Costa RicaConsejo Superior de Investigaciones Científicas/[CR0024]/CSIC/EspañaUniversidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Flavonoids and Ellagitannins Characterization, Antioxidant and Cytotoxic Activities of Phyllantus acuminatus Vahl.

The phenolic composition of leaves from Phyllanthus acuminatus L., a plant commonly used in Costa Rica as traditional medicine, was studied using UPLC-ESI-MS on an enriched phenolic extract. A total of 20 phenolic compounds were identified, comprising eight flavonoids (two flavanones—pinocembrin isomers and six derivatives from apigenin, chrysin, quercetin, and kaempferol); seven ellagitannins, two flavan-3-ols (prodelphinidin B dimer and (epi)gallocatechin); and three phenolic acids (ellagic acid, trimethylellagic acid, and ferulic acid). All of these compounds are reported for the first time in P. acuminatus, while previously reported in the genus Phyllanthus. Antioxidant evaluation was performed for P. acuminatus phenolic extract obtaining DPPH results with a remarkably low IC50 value of 0.15 µg/mL. Also, cytotoxicity on gastric AGS and colon SW20 adenocarcinoma cell lines was evaluated, and highly promising results were obtained, with IC50 values of 11.3 µg/mL and 10.5 µg/mL, respectively. Furthermore, selectivity index values obtained when comparing cytotoxicity on normal Vero cells was SI > 20 for both cancer cell lines, indicating a particularly high selectivity. Additionally, Justicidin B, a metabolite extensively studied for its antitumoral activity, was isolated from a non-polar extract of P. acuminatus, and comparatively evaluated for both bioactivities. The DPPH value obtained for Justicidin B was moderate (IC50 = 14.28 µg/mL), while cytotoxicity values for both AGS (IC50 = 19.5 µg/mL) and SW620 (IC50 = 24.8 µg/mL) cell lines, as well as selectivity when compared with normal Vero cells (SI = 5.4 and 4.2 respectively), was good, but lower than P. acuminatus extract. These preliminary results suggest that P. acuminatus enriched phenolic extract containing flavonoids, ellagitannins, flavan-3-ols, and phenolic acids, reported for the first time in this plant, could be of interest for further cancer cytotoxicity studies to elucidate structure–bioactivity relationships, and the molecular mechanisms and pathways.Consejo Nacional de Rectores/[Ref 115B0653]/CONARE/Costa RicaUniversidad de Costa Rica/[]/UCR/Costa RicaInstituto Tecnológico de Costa Rica/[]/TEC/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Polyphenolic Characterization and Antioxidant Activity of Malus domestica and Prunus domestica Cultivars from Costa Rica

The phenolic composition of skin and flesh from Malus domestica apples (Anna cultivar) and Prunus domestica plums (satsuma cultivar) commercial cultivars in Costa Rica, was studied using Ultra Performance Liquid Chromatography coupled with High Resolution Mass Spectrometry (UPLC-DAD-ESI-MS) on enriched-phenolic extracts, with particular emphasis in proanthocyanidin and flavonoids characterization. A total of 52 compounds were identified, including 21 proanthocyanidins ([(+)-catechin and (−)-epicatechin]) flavan-3-ols monomers, five procyanidin B-type dimers and two procyanidin A-type dimers, five procyanidin B-type trimers and two procyanidin A-type trimers, as well as one procyanidin B-type tetramer, two procyanidin B-type pentamers, and two flavan-3-ol gallates); 15 flavonoids (kaempferol, quercetin and naringenin derivatives); nine phenolic acids (protochatechuic, caffeoylquinic, and hydroxycinnamic acid derivatives); five hydroxychalcones (phloretin and 3-hydroxyphloretin derivatives); and two isoprenoid glycosides (vomifoliol derivatives). These findings constitute the first report of such a high number and diversity of compounds in skins of one single plum cultivar and of the presence of proanthocyanidin pentamers in apple skins. Also, it is the first time that such a large number of glycosylated flavonoids and proanthocyanidins are reported in skins and flesh of a single plum cultivar. In addition, total phenolic content (TPC) was measured with high values observed for all samples, especially for fruits skins with a TPC of 619.6 and 640.3 mg gallic acid equivalents/g extract respectively for apple and plum. Antioxidant potential using 2,2-diphenyl-1-picrylhidrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods were evaluated, with results showing also high values for all samples, especially again for fruit skins with IC50 of 4.54 and 5.19 µg/mL (DPPH) and 16.8 and 14.6 mmol TE/g (ORAC) respectively for apple and plum, indicating the potential value of these extracts. Significant negative correlation was found for both apple and plum samples between TPC and DPPH antioxidant values, especially for plum fruits (R = −0.981, p < 0.05) as well as significant positive correlation between TPC and ORAC, also especially for plum fruits (R = 0.993, p < 0.05) and between both, DPPH and ORAC antioxidant methods (R = 0.994, p < 0.05).Universidad de Costa Rica/[115-B4-515]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

UPLC-HRMS Polyphenolic Characterization, Contents and Antioxidant Activity of Zingiber officinale Roscoe rhizomes from Costa Rica

Zingiber offcinale Roscoe rhizomes have been associated with multiple health benefits, such as blocking blood clotting, digestive and antinausea effects and aid in respiratory conditions. These effects have been linked with their polyphenolic main metabolites, gingerols and shogaols. Herewith, we report a detailed study on the polyphenolic profile and in the contents of main gingerols and shogaol as well as the antioxidant activity of extracts from Z. offcinale rhizomes (n = 17) produced in Costa Rica. Using UPLC-QTOF-ESI MS, a total of 34 polyphenols were identified, grouped in twelve types of structures. In addition, our findings on the main metabolites using UPLC-DAD show all rhizomes complying with total gingerols (TG) content established by the United States Pharmacopeia (USP). At individual level, samples SR-1 and NR-4 show the higher contents and also exhibit the highest Folin-Ciocalteu (FC) reducing capacity results as well as the best DPPH antioxidant values. In addition, Pearson correlation analysis results showed positive correlation (p < 0.05) between TG and 6-gingerol with FC results and negative correlation (p < 0.05) between 6-gingerol, TG and FC with DPPH results. In turn, Principal Component Analysis (PCA) indicated variability in the composition associated with their region of origin and confirmed that NR-3, NR-4, and especially SR-1 stand out significatively, showing the highest PC1 because of its particularly high TG, 6-gingerol and antioxidant activities. Finally, results from controlled experimental plots of Z. officinale rhizomes (n = 6) indicated influence on metabolites content with higher values for shorter harvest time and high tunnel cultivation. Therefore, our findings indicate the value of Z. officinale in the elaboration of products with potential benefits for health, delivering extracts with higher levels of gingerols than previous reports and exhibiting high antioxidant activity.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

HRMS characterization, antioxidant and cytotoxic activities of polyphenols in Malus domestica cultivars from Costa Rica

There is increasing interest in research into fruits as sources of secondary metabolites because of their potential bioactivities. In this study, the phenolic profiles of Malus domestica Anna and Jonagold cultivars from Costa Rica were determined by Ultra Performance Liquid Chromatogra phy coupled with High Resolution Mass Spectrometry (HRMS) using a quadrupole-time-of-flight analyzer (UPLC-QTOF-ESI MS), on enriched-phenolic extracts from skins and flesh, obtained through Pressurized Liquid Extraction (PLE). In total, 48 different phenolic compounds were identified in the skin and flesh extracts, comprising 17 flavan-3-ols, 12 flavonoids, 4 chalcones, 1 glycosylated isoprenoid and 14 hydroxycinnamic acids and derivatives. Among extracts, the flesh of Jonagold exhibits a larger number of polyphenols and is especially rich in procyanidin trimers, tetramers and pentamers. Evaluating total phenolic content (TPC) and antioxidant activities using ORAC and DPPH procedures yields higher values for this extract (608.8 mg GAE/g extract; 14.80 mmol TE/g extract and IC50 = 3.96 µg/mL, respectively). In addition, cytotoxicity evaluated against SW620 colon cancer cell lines and AGS gastric cancer cell lines also delivered better effects for Jonagold flesh (IC50 = 62.4 and 60.0 µg/mL, respectively). In addition, a significant negative correlation (p < 0.05) was found between TPC and cytotoxicity values against SW620 and AGS adenocarcinoma (r = −0.908, and −0.902, respectively). Furthermore, a significant negative correlation (p < 0.05) was also found between the number of procyanidins and both antioxidant activities and cytotoxicity towards SW620 (r = −0.978) and AGS (r = −0.894) cell lines. These results align with Jonagold flesh exhibiting the highest abundance in procyanidin oligomers and yielding better cytotoxic and antioxidant results. In sum, our findings suggest the need for further studies on these Costa Rican apple extracts—and particularly on the extracts from Jonagold flesh—to increase the knowledge on their potential benefits for health.Universidad de Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Polyphenolic QTOF-ESI MS characterization and the antioxidant and cytotoxic activities of Prunus domestica.

There is an increased interest in plum research because of their metabolites’ potential bioactivities. In this study, the phenolic profiles of Prunus domestica commercial cultivars (Methley, Pisardii and Satsuma) in Costa Rica were determined by Ultra Performance Liquid Chromatogra phy coupled with High Resolution Mass Spectrometry using a quadrupole-time-of-flight analyzer (UPLC-ESI-QTOF MS) on enriched phenolic extracts obtained through Pressurized Liquid Extraction (PLE) under acidic and neutral extraction conditions. In total, 41 different phenolic compounds were identified in the skin and flesh extracts, comprising 11 flavan-3-ols, 14 flavonoids and 16 hydrox ycinnamic acids and derivatives. Neutral extractions for the skins and flesh from all of the cultivars yielded a larger number of compounds, and were particularly rich in the number of procyanidin trimers and tetramers when compared to the acid extractions. The total phenolic content (TPC) and antioxidant potential using the DPPH and ORAC methods exhibited better results for neutral extracts with Satsuma skins and Methley flesh, which showed the best values (685.0 and 801.6 mg GAE/g extract; IC50 = 4.85 and 4.39 µg/mL; and 12.55 and 12.22 mmol TE/g extract, respectively). A Two-Way ANOVA for cytotoxicity towards AGS gastric adenocarcinoma and SW620 colon adenocar cinoma indicated a significant difference (p < 0.05) for PLE conditions, with better results for neutral extractions, with Satsuma skin delivering the best results (IC50 = 60.7 and 46.7 µg/mL respectively) along with Methley flesh (IC50 = 76.3 and 60.9 µg/mL, respectively). In addition, a significant positive correlation was found between TPC and ORAC (r = 0.929, p < 0.05), as well as a significant negative correlation (p < 0.05) between TPC and cytotoxicity towards AGS and SW620 cell lines (r = −0.776, and −0.751, respectively). A particularly high, significant, negative correlation (p < 0.05) was found between the number of procyanidins and cytotoxicity against the AGS (r = −0.868) and SW620 (r = −0.855) cell lines. Finally, the PCA clearly corroborated that neutral extracts are a more homogenous group exhibiting higher antioxidant and cytotoxic results regardless of the part or cultivar; therefore, our findings suggest that PLE extracts under neutral conditions would be of interest for further studies on their potential health benefits.Universidad de Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Curcumin Hybrid Lipid Polymeric Nanoparticles: Antioxidant Activity, Immune Cellular Response, and Cytotoxicity Evaluation.

Poor solubility and short biological half-life present a challenge that needs to be overcome in order to improve the recognized bioactivities of curcumin (CUR), the main phenolic compounds derived from the roots of Curcuma longa. However, drug delivery systems have proven to be an excellent strategy to improve and obtain greater bioavailability. Our previous studies on curcuminoid hybrid nanoparticles have shown promising results by significantly increasing the solubility of desmethoxycurcumin (DMC) and bisdemethoxycurcumin (BDM). In this contribution, we performed a detailed characterization of a CUR as well as in vitro and in vivo studies. The developed method produced CUR loaded nanoparticles with an average size of 49.46 ± 0.80. Moreover, the FT-IR analysis confirmed the encapsulation, and TEM images showed their spherical shape. The NP achieved an encapsulation efficiency greater than 99%. Further, the release studies found that the NPs obtained a significantly higher release than the pure compounds in water. In vivo delayed-type hypersensitivity (DTH) studies showed promising results by enhancing the immune activity response of CUR in NP compared to bulk CUR. Furthermore, we report a significant increase in antioxidant activity for CUR-NP in aqueous solution compared to free CUR. Finally, an important in vitro cytotoxic effect on gastric AGS and colon SW620 adenocarcinoma cell lines was found for CUR-NP while empty carrier nanoparticles are observed to exhibit low cytotoxicity, indicating the potential of these CUR-PLU NPs for further studies to assess their phytotherapeutic applications.National Laboratory of Nanotechnology (LANOTEC).Ministerio de Ciencia, Innovación, Tecnología y Telecomunicaciones (MICITT)Universidad de Costa Rica/[115-C0-001]/UCR/Costa RicaUniversidad de Costa Rica/[115-C1-515]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Farmaci

Proanthocyanidin Characterization, Antioxidant and Cytotoxic Activities of Three Plants Commonly Used in Traditional Medicine in Costa Rica: Petiveria alliaceae L., Phyllanthus niruri L. and Senna reticulataWilld

The phenolic composition of aerial parts from Petiveria alliaceae L., Phyllanthus niruri L. and Senna reticulata Willd., species commonly used in Costa Rica as traditional medicines, was studied using UPLC-ESI-TQ-MS on enriched-phenolic extracts. Comparatively, higher values of total phenolic content (TPC), as measured by the Folin-Ciocalteau method, were observed for P. niruri extracts (328.8 gallic acid equivalents/g) than for S. reticulata (79.30 gallic acid equivalents/g) whereas P. alliaceae extract showed the lowest value (13.45 gallic acid equivalents/g). A total of 20 phenolic acids and proanthocyanidins were identified in the extracts, including hydroxybenzoic acids (benzoic, 4-hydroxybenzoic, gallic, prochatechuic, salicylic, syringic and vanillic acids); hydroxycinnamic acids (caffeic, ferulic, and p-coumaric acids); and flavan-3-ols monomers [(+)-catechin and (−)-epicatechin)]. Regarding proanthocyanidin oligomers, five procyanidin dimers (B1, B2, B3, B4, and B5) and one trimer (T2) are reported for the first time in P. niruri, as well as two propelargonidin dimers in S. reticulata. Additionally, P. niruri showed the highest antioxidant DPPH and ORAC values (IC50 of 6.4 μg/mL and 6.5 mmol TE/g respectively), followed by S. reticulata (IC50 of 72.9 μg/mL and 2.68 mmol TE/g respectively) and P. alliaceae extract (IC50 >1000 μg/mL and 1.32 mmol TE/g respectively). Finally, cytotoxicity and selectivity on gastric AGS and colon SW20 adenocarcinoma cell lines were evaluated and the best values were also found for P. niruri (SI = 2.8), followed by S. reticulata (SI = 2.5). Therefore, these results suggest that extracts containing higher proanthocyanidin content also show higher bioactivities. Significant positive correlation was found between TPC and ORAC (R2 = 0.996) as well as between phenolic content as measured by UPLC-DAD and ORAC (R2 = 0.990). These findings show evidence for the first time of the diversity of phenolic acids in P. alliaceae and S. reticulata, and the presence of proanthocyanidins as minor components in latter species. Of particular relevance is the occurrence of proanthocyanidin oligomers in phenolic extracts from P. niruri and their potential bioactivityUniversidad de Costa Rica/[115-B0-653]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Characterization and Isolation of Piperamides from Piper nigrum cultivated in Costa Rica

The piperamides profile of Piper nigrum cultivated in Costa Rica was studied using Ultra Perfor-mance Liquid Chromatography coupled with Electrospray Ionization Quadrupole Time-of-Flight High Resolution Mass Spectrometry (UPLC-ESI-QTOF-HRMS) on enriched-piperamides extracts. A total of 31 different piperamides were identified, 24 of them with a methylenedioxyphenyl moiety, including piperine and nine other compounds with the characteristic piperidine ring, as well as guineensine, retrofractamide B and eight other piperamides with an N-isobutyl group. In addition, piperyline and two other compounds with a pyrrolidine ring as well as piperflaviflorine B, holding a N-2-methylbutyl chain, were characterized. In turn, pellitorine and six other piperamides exhib-iting a long olefinic chain instead of the methylenedioxyphenyl group, were also tentatively iden-tified. In addition, quantification was performed using UPLC coupled with Diode Array Detector (UPLC-DAD), with 15 piperamides being quantified, including piperine, piperyline, piperanine, and piperloguminine with values within the range of previous reports, while results obtained for guineensine (276.5 - 421.0 mg/100 g dry material) and pellitorine (414.4 - 725.0 mg/100 g dry ma-terial) are higher than those reported in the literature. Additionally, preparative and semi-preparative High Performance Liquid Chromatography (HPLC) separations allowed to iso-late, besides piperine, four other piperamides, which were identified through HRMS, 1H and 13C Nuclear Magnetic Resonance (NMR), including retrofractamide B, guineensine, pellitorine, and (2E,4E,12Z)-N-isobutyl-octadeca-2,4,12-trienamide, with yields of 134.0 mg/100 g dry material, 209.7 mg/100 g dry material, 361.8 mg/100 g dry material and 467.0 mg/100 g dry material, re-spectively, with all these values higher than those reported in previous studies in the literature. The findings constitute the first report of such a number and diversity of compounds in P. nigrum cul-tivated in Costa Rica.Universidad de Costa Rica/[115-B6-163]/UCR/Costa RicaUniversidad de Costa Rica/[115-C0-001]/UCR/Costa RicaUniversidad de Costa Rica/[115-C3-005]/UCR/Costa RicaUniversidad de Costa Rica/[ED-2033]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Polyphenolic HRMS Characterization, Contents and Antioxidant Activity of Curcuma longa rhizomes from Costa Rica

Curcuma longa constitutes an important source of secondary metabolites that have been associated with multiple health benefits. For instance, curcumin, demethoxycurcumin and bisdemethoxy-curcumin, have been found to perform important biological activities, such as anti-inflammatory, antioxidant, anticancer, antimicrobial, antihypertensive and anticoagulant. These promising results prompted this research to evaluate the polyphenols of C. longa rhizomes in Costa Rica. The present work reports a comprehensive study on the polyphenolic profile and the contents of the three main curcuminoids as well as the antioxidant activity of extracts from C. longa rhizomes (n = 12) produced in Costa Rica. Through UPLC-QTOF-ESI MS, a total of 33 polyphenols were identified, grouped in eight types of structures. In addition, our findings on the main curcuminoids using UPLC-DAD show all rhizomes complying with total curcuminoids (TC) content established by the United States Pharmacopeia (USP). At individual level, samples NW-3 and NE-1 show the higher contents (118.7 and 125.0 mg/g dry material), representing more than twice the average values of the lowest samples. These samples also exhibit the highest Folin-Ciocalteu (FC) reducing capacity results as well as the best DPPH (IC50 15.21 and 16.07 µg extract/mL) and NO (IC50 between 52.5 and 54.3 µg extract/mL) antioxidant values. Further, Pearson correlation analysis findings indicated positive correlation (p < 0.05) between TC, CUR with FC results (r = 0.833 and r = 0.867 respectively) and negative correlation (p < 0.05) between CUR, TC and FC with DPPH results (r = -0.898, r = -0.911, and r = -0.890, respectively) and between NO results and DPPH (r = -0.805, p < 0.05). Finally, results for Principal Component Analysis (PCA) showed composition variability associated with their re-gion of origin with products from the Northeastern (NE) region exhibiting higher average values for FC, TC and antioxidant activities. Further, PCA confirmed that two samples, namely NE-1 and NW-3 stand out by presenting the highest PC1 due to their particularly high TC, CUR and anti-oxidant activities. Consequently, our findings agree with previous results indicating the importance of C. longa extracts to elaborate products with potential benefits for health, while delivering extracts with higher levels of curcuminoids than previous reports and exhibiting high antioxidant activity.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin