RESUMEN
Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder worldwide, and the therapeutic is focused on several approaches including the inhibition of fibril formation by small compounds, avoiding the formation of cytotoxic oligomers. Thus, we decided to explore the capacity of compounds carrying catechol moieties to inhibit the progression of α-synuclein. Overall, the compounds rosmarinic acid (1), carnosic acid (2), carnosol (3), epiisorosmanol (4), and rosmanol (5) avoid the progression of fibril formation assessed by Thiofavine T (ThT), and atomic force microscopy images showed that morphology is influenced for the actions of compounds over fibrillization. Moreover, ITC experiments showed a Kd varying from 28 to 51 µM, the ΔG showed that the reaction between compounds and α-syn is spontaneous, and ΔH is associated with an exothermic reaction, suggesting the interactions of hydrogen bonds among compounds and α-syn. Docking experiments reinforce this idea showing the intermolecular interactions are mostly hydrogen bonding within the sites 2, 9, and 3/13 of α-synuclein, and compounds 1 and 5. Thus, compound 1, rosmarinic acid, interestingly interacts better with site 9 through catechol and Lysines. In cultured Raw 264. 7 cells, the presence of compounds showed that most of them can promote cell differentiation, especially rosmarinic acid, and rosmanol, both preserving tubulin cytoskeleton. However, once we evaluated whether or not the aggregates pre-treated with compounds could prevent the disruption of microtubules of Raw 264.7 cells, only pre-treated aggregates with rosmarinic acid prevented the disruption of the cytoskeleton. Altogether, we showed that especially rosmarinic acid not only inhibits α-syn but stabilizes the remaining aggregates turning them into not-toxic to Raw 264.7 cells suggesting a main role in cell survival and antigen processing in response to external α-syn aggregates.
Asunto(s)
Cinamatos , Depsidos , Microtúbulos , Ácido Rosmarínico , alfa-Sinucleína , Depsidos/farmacología , Depsidos/química , Depsidos/aislamiento & purificación , Cinamatos/química , Cinamatos/farmacología , Cinamatos/síntesis química , Animales , Ratones , Células RAW 264.7 , Microtúbulos/efectos de los fármacos , Microtúbulos/metabolismo , Estructura Molecular , alfa-Sinucleína/metabolismo , alfa-Sinucleína/antagonistas & inhibidores , Relación Estructura-Actividad , Relación Dosis-Respuesta a Droga , Supervivencia Celular/efectos de los fármacos , Simulación del Acoplamiento MolecularRESUMEN
The phytochemical profile of Lepechinia meyenii (Walp.) Epling and Lepechina floribunda (Benth.) Epling obtained by liquid chromatography associated with high-resolution mass spectrometry is presented. Forty eight compounds were detected exhibiting a variety of salvianolic acids and abietane phenolic diterpenoids. A simple procedure by cold evaporative crystallization to purify rosmarinic acid from these botanical species was also shown.
Asunto(s)
Cinamatos/química , Cinamatos/aislamiento & purificación , Depsidos/química , Depsidos/aislamiento & purificación , Lamiaceae/química , Cromatografía Liquida , Espectrometría de Masas , Ácido RosmarínicoRESUMEN
Alzheimer´s disease (AD) is the most common form of dementia involving Aß and tau protein. So far, AD cure remains elusive, but considering that AD progresses throughout tau pathology, which turns tau protein an appropriate target, besides tau is also included in other neurodegenerative disorders named as tauopathies. Here, we have isolated seventeen compounds belonging to six lichens species. Due to scarce of spectroscopic data of the compound 5,7-dihydroxy-6-methylphthalide, we explained their structural elucidation based on NMR data. In this study, we show that only tenuiorin from Umbilicaria antarctica inhibited 50% of tau 4R at 100 µM. Then, we shown that molecular interactions of tenuiorin with the steric zipper model of the hexapeptide 306VQIVYK311 were studied by docking calculations and the results suggested that tenuiorin forms both hydrogen bonds with lysine and glutamine side chains and forms several hydrophobic interactions with valine and lysine from 306VQIVYK311 motif.
Asunto(s)
Ascomicetos/química , Depsidos/aislamiento & purificación , Líquenes/química , Resorcinoles/aislamiento & purificación , Proteínas tau/antagonistas & inhibidores , Enfermedad de Alzheimer/tratamiento farmacológico , Regiones Antárticas , Ascomicetos/metabolismo , Sitios de Unión , Depsidos/química , Humanos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Unión Proteica , Resorcinoles/química , Resorcinoles/metabolismo , Proteínas tau/metabolismoRESUMEN
Nine previously undescribed depsidones (simplicildones A-I) and one previously undescribed α-pyrone (simplicilopyrone) were isolated from the endophytic fungus Simplicillium sp. PSU-H41 along with 11 known compounds. Their structures were established by extensive spectroscopic analysis. Simplicildone A and known botryorhodine C displayed weak antibacterial against Staphylococcus aureus with equal MIC values of 32 µg/mL. Additionally, botryorhodine C was active against methicillin-resistant S. aureus with the same MIC value. Simplicildone C exhibited weak antifungal activity against Cryptococcus neoformans with an MIC value of 32 µg/mL. In addition, simplicildones A and C and botryorhodine C were noncytotoxic against noncancerous Vero cells.
Asunto(s)
Antibacterianos/aislamiento & purificación , Antifúngicos/aislamiento & purificación , Depsidos/aislamiento & purificación , Euphorbiaceae/química , Hevea/química , Lactonas/aislamiento & purificación , Pironas/aislamiento & purificación , Animales , Antibacterianos/química , Antibacterianos/farmacología , Antifúngicos/química , Antifúngicos/farmacología , Chlorocebus aethiops , Cryptococcus neoformans/efectos de los fármacos , Depsidos/química , Depsidos/farmacología , Lactonas/química , Lactonas/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Hojas de la Planta/química , Pironas/química , Pironas/farmacología , Staphylococcus aureus/efectos de los fármacos , Células VeroRESUMEN
Alzheimer's disease is a common tauopathy where fibril formation and aggregates are the hallmark of the disease. Efforts targeting amyloid-ß plaques have succeeded to remove plaques but failed in clinical trials to improve cognition; thus, the current therapeutic strategy is at preventing tau aggregation. Here, we demonstrated that four phenolic diterpenoids and rosmarinic acid inhibit fibrillization. Since, rosmarinic acid was the most active compound, we observe morphological changes in atomic force microscopy images after treatment. Hence, rosmarinic acid leads to a decrease in amide regions I and III, indicating that rosmarinic acid prevents ß-sheet assembly. Molecular docking study inside the steric zipper model of the hexapeptide 306VQIVYK311 involved in fibrillization and ß sheet formation, suggests that rosmarinic acid binds to the steric zipper with similar chemical interactions with respect to those observed for orange G, a known pharmacofore for amyloid.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Cinamatos/farmacología , Depsidos/farmacología , Proteínas tau/antagonistas & inhibidores , Enfermedad de Alzheimer/metabolismo , Cinamatos/química , Cinamatos/aislamiento & purificación , Depsidos/química , Depsidos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Humanos , Simulación del Acoplamiento Molecular , Estructura Molecular , Agregado de Proteínas/efectos de los fármacos , Conformación Proteica en Lámina beta , Rosmarinus/química , Relación Estructura-Actividad , Vibración , Proteínas tau/metabolismo , Ácido RosmarínicoRESUMEN
Lichens are a form of symbiont between a fungus and an alga or cyanobacterium, which contains a wide variety of organic compounds with certain secondary metabolite classes typical of these organisms. The Ramalina genus has approximately 246 species distributed around the World, of which in this review approximately 118 species with published chemical or biological activity studies of extracts or isolated compounds were cited. From the 153 mentioned compounds, only 27 passed were tested for biological activity, being usnic acid the most studied compound and the one showing the best results in almost all in vitro tests performed, although other compounds also presented excellent results as antimicrobial, antitumor and anti-inflammatory agents, among others. Extracts of several species also presented significant results in performed biological tests, demonstrating the potential that these organisms have, in particular, the gender Ramalina, to produce bioactive molecules that can be used as a model for the production of pharmaceuticals.
Asunto(s)
Líquenes/química , Líquenes/fisiología , Animales , Benzofuranos/aislamiento & purificación , Benzofuranos/farmacología , Depsidos/aislamiento & purificación , Depsidos/farmacología , HumanosRESUMEN
Rosmarinus officinalis, also named rosemary, is a native plant from the Mediterranean region that is useful for the treatment of inflammatory diseases. Studies using experimental models and/or in vitro tests have shown the important biological effects of rosemary. In this context, the mechanism of the anti-inflammatory activity of rosemary must be investigated to support the discovery of new substances with anti-inflammatory effects. The aim of the present study was to investigate the anti-inflammatory effects of crude extract oil free obtained from the leaves of rosemary in an animal model of inflammation, thus evaluating its medicinal use for the treatment of inflammatory conditions. Also its ethanol, hexane, and ethyl acetate fractions, as well as its isolated compounds carnosol and rosmarinic acid were analyzed. Swiss mice were used for the in vivo experiments. The effect of this herb on the inhibition of the leukocytes, exudation, myeloperoxidase, and adenosine-deaminase activities, nitrite/nitrate, interleukin 17A, and interleukin 10 levels and mRNA expression was determined. The crude extract and its derived fractions, in addition to its isolated compounds, inhibited leukocytes and decreased exudation and myeloperoxidase and adenosine-deaminase activities, as well as nitrite/nitrate and interleukin 17A levels and mRNA expression, besides increasing interleukin 10 levels and mRNA expression. Rosemary showed important anti-inflammatory activity by inhibiting leukocytes and decreasing exudation. These effects were associated with a decrease in the proinflammatory parameters (myeloperoxidase, adenosine-deaminase, nitrite/nitrate, and interleukin 17A) and an increase in the anti-inflammatory cytokine (interleukin 10). This study confirms the anti-inflammatory properties of rosemary and validates its use in folk medicine to treat inflammatory diseases such as rheumatism and asthma.
Asunto(s)
Antiinflamatorios/uso terapéutico , Mediadores de Inflamación/metabolismo , Inflamación/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Pleuresia/tratamiento farmacológico , Rosmarinus/química , Abietanos/aislamiento & purificación , Abietanos/farmacología , Abietanos/uso terapéutico , Adenosina Desaminasa/metabolismo , Animales , Antiinflamatorios/farmacología , Carragenina , Cinamatos/aislamiento & purificación , Cinamatos/farmacología , Cinamatos/uso terapéutico , Citocinas/genética , Citocinas/metabolismo , Depsidos/aislamiento & purificación , Depsidos/farmacología , Depsidos/uso terapéutico , Modelos Animales de Enfermedad , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/metabolismo , Leucocitos/metabolismo , Ratones , Ratones Endogámicos , Nitratos/metabolismo , Nitritos/metabolismo , Peroxidasa/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta , Pleuresia/inducido químicamente , Pleuresia/genética , Pleuresia/metabolismo , ARN Mensajero/metabolismo , Ácido RosmarínicoRESUMEN
CONTEXT: Despite several pharmacological applications of Rosmarinus officinalis L. (Lamiaceae), studies on its analgesic and anti-inflammatory properties have been scarce. OBJECTIVE: The aim of this work was to use in vivo models to evaluate the analgesic and anti-inflammatory activities of the aqueous extracts obtained from leaves (AEL) and stems (AES) of Rosmarinus officinalis, as well as its isolated compound--rosmarinic acid (RA). We also prepared and assessed the acetyl ester derivative of RA. MATERIALS AND METHODS: The analgesic activity was evaluated using abdominal constriction and formalin tests. For the evaluation of the anti-inflammatory effects, carrageenin-induced paw edema in rats were used. The extracts were used at doses of 100, 200 and 400 mg kg⻹ compounds were tested at 10, 20 and 40 mg kg⻹. RESULTS: Orally administered AEL, AES and RA were not significantly active at any of the doses tested during the abdominal constriction test; the acetyl ester derivative of RA displayed significant analgesic activity. In the carrageenin-induced paw edema assay, the acetyl derivative of RA at all the tested doses produced significant anti-inflammatory effects and reduced the number of paw licks in the second phase of the formalin test. DISCUSSION AND CONCLUSION: The results suggest that the analgesic effects of the acetyl derivative of RA operate via a peripheral-mediated mechanism. The acetyl ester derivative of RA is potentially applicable as a new lead compound for the management of pain and inflammation.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Cinamatos/uso terapéutico , Depsidos/uso terapéutico , Modelos Animales de Enfermedad , Neuralgia/prevención & control , Inflamación Neurogénica/prevención & control , Extractos Vegetales/uso terapéutico , Rosmarinus/química , Acetilación , Administración Oral , Animales , Antiinflamatorios no Esteroideos/aislamiento & purificación , Conducta Animal/efectos de los fármacos , Brasil , Cinamatos/administración & dosificación , Cinamatos/química , Cinamatos/aislamiento & purificación , Depsidos/administración & dosificación , Depsidos/química , Depsidos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Etnofarmacología , Masculino , Medicina Tradicional , Ratones , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Tallos de la Planta/química , Ratas , Ratas Wistar , Ácido RosmarínicoRESUMEN
Baccharis plants have been used since ancient times in American traditional medicine. Baccharis chilco is a perennial shrub of temperate regions of South America that grows well in rainfall forests of Colombia. Neither chemical composition nor biological studies of this plant have ever been reported. Two caffeoylquinic acid (CQA) derivatives, 5-O-[(E)-caffeoyl]quinic acid (1) and 3,5-di-O-[(E)-caffeoyl]quinic acid (3), and rosmarinic acid (2) have been isolated from B. chilco growing wild in Colombia, using the on-line HPLC-DAD-DPPH radical-scavenging detection technique as guidance. In the course of the purification work, L-chiro-inositol (4) was also isolated. Structures of the four isolated compounds were determined by spectroscopic methods. Antioxidants 2 and 3 exhibited high antiradical activities evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(.)) assay, although somewhat lower than that of the reference compound ascorbic acid. The on-line HPLC-DAD-DPPH technique allowed a rapid pinpointing of antioxidants in the studied EtOH extract, and the facile guided isolation of the target molecules.
Asunto(s)
Baccharis/química , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Compuestos de Bifenilo/química , Cromatografía Líquida de Alta Presión/métodos , Cinamatos/química , Cinamatos/aislamiento & purificación , Cinamatos/farmacología , Depsidos/química , Depsidos/aislamiento & purificación , Depsidos/farmacología , Depuradores de Radicales Libres/aislamiento & purificación , Radicales Libres/química , Inositol/química , Inositol/aislamiento & purificación , Inositol/farmacología , Picratos/química , Extractos Vegetales/aislamiento & purificación , Ácido Quínico/análogos & derivados , Ácido Quínico/química , Ácido Quínico/aislamiento & purificación , Ácido Quínico/farmacología , Ácido RosmarínicoRESUMEN
Solanum guaraniticum is a shrub belonging to the Solanaceae family popularly known in Brazil as jurubeba or false-jurubeba. The aim of this study was to evaluate the antioxidant activity of crude extract and chloroform, ethyl acetate and n-butanol fractions from its leaves, verifying the ability to remove reactive species and identify and quantify phenolic compounds. The ethyl acetate fraction showed the highest amount of total polyphenols (546.57 ± 2.35 mg gallic acid equivalent/g) and the lowest IC(50) (9.11 ± 0.75 µg/mL) by the DPPH method. Furthermore, the chloroform fraction presented the highest content of flavonoids (75.73 ± 0.34 mg rutin equivalents/g), tannins (56.03 ± 0.68 mg catechin equivalents/g) and alkaloids (10.79 ± 0.06 mg/g). This fraction was effective in the scavenging of reactive species by 2',7'-dichlorofluorescein diacetate assay, in addition to completely reducing protein carbonyl content and reducing lipid peroxidation at basal levels even at low concentrations. Chlorogenic, caffeic and rosmarinic acids were identified and quantified by HPLC/DAD. These results show that S. guaraniticum is rich in phenolic compounds and has potential as an antioxidant.
Asunto(s)
Depuradores de Radicales Libres/química , Extractos Vegetales/química , Hojas de la Planta/química , Solanum/química , Alcaloides/química , Alcaloides/aislamiento & purificación , Animales , Compuestos de Bifenilo/química , Proteínas Sanguíneas/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Ácidos Cafeicos/química , Ácidos Cafeicos/aislamiento & purificación , Ácido Clorogénico/química , Ácido Clorogénico/aislamiento & purificación , Cinamatos/química , Cinamatos/aislamiento & purificación , Depsidos/química , Depsidos/aislamiento & purificación , Flavonoides/química , Flavonoides/aislamiento & purificación , Fluoresceínas/química , Depuradores de Radicales Libres/aislamiento & purificación , Depuradores de Radicales Libres/farmacología , Concentración 50 Inhibidora , Peroxidación de Lípido/efectos de los fármacos , Masculino , Estrés Oxidativo/efectos de los fármacos , Picratos/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Plantas Medicinales/química , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Taninos/química , Taninos/aislamiento & purificación , Sustancias Reactivas al Ácido Tiobarbitúrico/química , Ácido RosmarínicoRESUMEN
Allergic asthma has emerged as an important public health problem of urban populations in developed countries. Very often herbal medicine is used to treat this widespread disease, due to the lack of efficacy and the important side effects related to the classical drugs in use. Along this line, Ocimum gratissimum (Og) is a plant widely used in Brazilian folk medicine to treat inflammatory disorders, such as asthma. In the present study we evaluated the immunomodulatory effects of Og and rosmarinic acid (RA, a polyphenolic compound) in a murine model of respiratory allergy induced by the Blomia tropicalis (Bt) mite. The respiratory allergy was induced in A/J mice by administration of Bt extract and the treatment was done using 25, 50 or 100mg/kg of an Og methanolic extract or using 2, 20 or 200mg/kg of RA. We then evaluated the changes induced by these drugs on immunological parameters related to the allergic process, which are up-regulated in this allergic model. The treatment of animals with 100mg/Kg Og and 200mg/Kg RA led to a significant reduction in the numbers of leukocytes/eosinophils in bronchoalveolar lavage (BAL); eosinophil peroxidase activity in BAL; presence of mucus in respiratory tract, histopathological changes in the lung, and IL-4 in BAL. These results suggest that the methanolic extract of Og and the polyphenol RA have therapeutic potential in this murine model of respiratory allergy to a clinically relevant human sensitizer allergen.
Asunto(s)
Cinamatos/uso terapéutico , Depsidos/uso terapéutico , Eosinófilos/inmunología , Factores Inmunológicos/uso terapéutico , Ocimum/química , Extractos Vegetales/uso terapéutico , Hipersensibilidad Respiratoria/tratamiento farmacológico , Sarcoptidae/inmunología , Animales , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Cinamatos/administración & dosificación , Cinamatos/aislamiento & purificación , Depsidos/administración & dosificación , Depsidos/aislamiento & purificación , Modelos Animales de Enfermedad , Peroxidasa del Eosinófilo/metabolismo , Eosinófilos/efectos de los fármacos , Eosinófilos/enzimología , Factores Inmunológicos/administración & dosificación , Factores Inmunológicos/aislamiento & purificación , Interleucina-4/inmunología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos , Extractos Vegetales/administración & dosificación , Extractos Vegetales/aislamiento & purificación , Hipersensibilidad Respiratoria/inmunología , Hipersensibilidad Respiratoria/patología , Mucosa Respiratoria/inmunología , Ácido RosmarínicoRESUMEN
Rosmarinic acid (RA) is a naturally occurring phenolic compound, which contributes to the beneficial and health-promoting effects of herbs, spices and medicinal plants. RA has shown several biological activities, such as hepatoprotective, anti-inflammatory, antiangiogenic, antitumor, antidepressant, antineurodegenerative, HIV-1 inhibitory and antioxidant effects. The aim of this study was to investigate the ability of RA to prevent chemically induced chromosome breakage or loss and primary DNA damage using the micronucleus and comet assays with V79 cells, respectively. The chemotherapeutic agent doxorubicin (DXR; 0.5 microg ml(-1)) was used as the DNA-damaging agent. The cultures were treated with different concentrations of RA (0.28, 0.56 and 1.12 mm) alone or in combination with DXR. The results showed that RA exerted no genotoxic effect, but significantly reduced the frequency of micronuclei and the extent of DNA damage induced by DXR at the three concentrations tested. The antioxidant activity of RA might be involved in the reduction of DXR-induced DNA damage observed in the present study.
Asunto(s)
Antimutagênicos/farmacología , Cinamatos/farmacología , Depsidos/farmacología , Animales , Antimutagênicos/química , Antimutagênicos/aislamiento & purificación , Antineoplásicos/toxicidad , Línea Celular , Quimioprevención , Rotura Cromosómica/efectos de los fármacos , Deleción Cromosómica , Cinamatos/química , Cinamatos/aislamiento & purificación , Ensayo Cometa , Cricetinae , Cricetulus , Daño del ADN/efectos de los fármacos , Depsidos/química , Depsidos/aislamiento & purificación , Doxorrubicina/toxicidad , Fibroblastos , Pruebas de Micronúcleos , Mutágenos/toxicidad , Concentración Osmolar , Hojas de la Planta/química , Rosmarinus/química , Ácido RosmarínicoRESUMEN
Four new depsidones, mollicellins K-N (1-4), and six known depsidones, mollicellins B (5), C (6), E (7), F (8), H (9), and J (10), along with two known sterols were isolated from the fungus Chaetomium brasiliense. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic data and chemical transformation. Among these isolates, 1-3, 5-7, and 10 exhibited antimalarial activity against Plasmodium falciparum. Only 1 exhibited antimycobacterial activity against Mycobacterium tuberculosis and antifungal activity against Candida albicans using in vitro assays. In addition, 1-10 showed cytotoxicity against the KB, BC1, NCI-H187, and five cholangiocarcinoma cell lines.
Asunto(s)
Antimaláricos/aislamiento & purificación , Antimaláricos/farmacología , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Antituberculosos/aislamiento & purificación , Antituberculosos/farmacología , Chaetomium/química , Depsidos/aislamiento & purificación , Depsidos/farmacología , Lactonas/aislamiento & purificación , Lactonas/farmacología , Animales , Antimaláricos/química , Antineoplásicos/química , Antituberculosos/química , Candida albicans/efectos de los fármacos , Depsidos/química , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Lactonas/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Mycobacterium tuberculosis/efectos de los fármacos , Resonancia Magnética Nuclear Biomolecular , Plasmodium falciparum/efectos de los fármacos , TailandiaRESUMEN
In addition to the free protein amino acid l-tyrosine, the expanding young leaves of Inga laurina accumulate high concentrations of three new depsides, galloyl, m-digalloyl, and m-trigalloyl l-tyrosine (1, 2, and 3). The structures of these compounds were determined on the basis of their spectroscopic properties and through degradation and derivatization experiments. They occur in young leaves at the following dry-weight mass percentages: tyrosine, 10.4%; 1, 3.1%; 2, 5.0%; 3, 1.3%. These concentrations are most consistent with chemical defense during the vulnerable expansion stage of leaf development. Neither free tyrosine nor its galloyl depsides are present in mature leaves.