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Olga Lock

Pontificia Universidad Catolica del Peru, Departamento de ciencias. Sección Química, Faculty Member

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My name is Olga R. Lock Sing. I am a Chemical Engineer and a Doctor in Chemical Sciences. My main research topic is Phytochemistry. I study the chemistry of Peruvian plants, their use in medicine and/or dyeing. I have published 100+ papers and invited to participate in 150+ international and national conferences.

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Kristen J Gremillion

Ohio State University

Centro de Investigacion y Estudios Avanzados del IPN

University of Karachi

José G Teixeira Junior

Universidade Federal de Uberlândia

Calicut University

Chemistry International

University of East London

Gwen Robbins Schug

University of North Carolina at Greensboro

Gabriel Gutierrez-Alonso

University of Salamanca

Macquarie University

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Books by Olga Lock

QUIMICA 25 AÑOS DE REALIZACIONES

by NADIA GAMBOA and Olga Lock

Papers by Olga Lock

$Research paper thumbnail of Protective effect of dried latex and alkaloid fraction of Croton palanostigma against gastric mucosal injury induced by ethanol in rats$

Protective effect of dried latex and alkaloid fraction of Croton palanostigma against gastric mucosal injury induced by ethanol in rats

Estudio químico-farmacológico de la werneria poposa philippi

Boletin De La Sociedad Quimica Del Peru, 1998

Sing de Ugaz, O.L., Colorantes Naturales. Lima, Perú., Fondo Editorial, 1997. 274p

Boletín de la Sociedad Química del Perú, 1997

Química y Farmacología de Smallanthus sonchifolius (Poepp.) H. Rob. ("Yacón")

This review article covers the present knowledge on the chemistry and biological activities of Sm... more This review article covers the present knowledge on the chemistry and biological activities of Smallanthus sonchifolius (Poepp.) H. Rob. A description of the chemical compounds reported in the scientific literature (i.e. oligofructans, phenolic compounds and terpenes) is included. The biological activities of the crude extracts of leaves and roots from yacon are discussed.

Article Antioxidant Bibenzyl Derivatives from Notholaena nivea Desv

Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-gui... more Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-guided fractionation of a CHCl 3-MeOH extract of Notholaena nivea Desv. (Pteridaceae) aerial parts. The structures were elucidated by NMR, ESIMS and other spectral analyses. Their antioxidative effects towards superoxide, lipidic peroxidation and the 2,2'-azino-bis-3-ethilbenzothiazoline-6-sulfonic acid (ABTS) radical were assayed. Results showed that the compound 3,12-dihydroxy-5-methoxybibenzyl (6) is the most active compound in the ABTS free-radical scavenging test, while in the coupled oxidation of β-carotene and linoleic acid assay the compound 5,12-dihydroxy-3-methoxydibenzyl-6carboxylic acid (1) exerted the highest activity after 1h. A superoxide anion enzymatic test was also carried out and the results were confirmed by an inhibition of xanthine oxidase activity assay. The putative protective role played by compounds 1 and 6 on the injurious effects of reactive oxygen metabolites on the intestinal epithelium, using a Caco-2 human cell line, was investigated. H 2 O 2-induced alterations were prevented by preincubating the cells with compounds 1 and 6.

Química y Farmacología del Piper aduncum L. ("Matico")

This review article covers the present knowledge on the chemistry and biological activities of Pi... more This review article covers the present knowledge on the chemistry and biological activities of Piper aduncurn and its synonyms P. angustifoliurn and P. elongaturn. More than 50 compounds have been isolated from these species, which can be grouped as chromenes, phenylpropanoids, benzoic acid derivatives and flavonoids. The biological activities of the crude extracts, and the compounds isolated from them, are discussed. Palabras claves: Piper aduncum, matico, antim icrobiano, Piper angustifolium, Piper elongatum

Química y Farmacología de Physalis peruviana L. (''Aguaymanto'')

This review article covers the present knowledge on the chemistry and biological activities of Ph... more

Revalorizando el uso milenario del sacha inchi (Plukenetia volubilis L.) para la nutrición, la salud y la cosmética

Química y farmacología del Croton lechleri Muell.Arg., ("Sangre de grado")

La presente publicacion pretende dar una vision del conocimiento cientifico quimico- biologico de... more La presente publicacion pretende dar una vision del conocimiento cientifico quimico- biologico del Croton lechleri Muell. Arg., "sangre de grado", esperando asi brindar un aporte para su mejor conocimiento y aprovechamiento. Del Croton lechleri se han reportado constituyentes quimicos como alcaloides, fenolicos, diterpenos y esteroides. Asimismo, los reportes cientificos indican que se han realizado diversos ensayos biologicos para evaluar su actividad antimicrobiana, antioxidante, antimutagen ica, citotoxica, anti inflamatoria, inmunomoduladora y cicatrizante. Se discuten los resultados reportados.

Federación Latinoamericana de Asociaciones Químicas

Chemistry International -- Newsmagazine for IUPAC, 2013

T he Federación Latinoamericana de Asociaciones Químicas (FLAQ) is the representative body for sc... more T he Federación Latinoamericana de Asociaciones Químicas (FLAQ) is the representative body for scientific partnerships and/or chemical professionals of the nations of Latin America. Founded in 1959, FLAQ promotes exchanges between higher educational institutions to respond to urgent development responsibilities in Latin America, encourages research and international meetings on chemical problems, generates media coverage of advances in chemistry, and organizes the Latin American Chemistry Congress. Different types of groups belong to the FLAQ. In some countries, such as Bolivia,

Phytochemistry and biological activities of Werneria and Xenophyllum species

Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are us... more Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are used in traditional medicine of Latin America for the treatment of mountain sickness, hypertension and gastrointestinal disorders. Only a small number of species of these genera have been studied, leading to the isolation of compounds belonging to the classes of benzofurans, chromenes, acetophenones, coumarates, diterpenes and pyrrolizidine alkaloids. Some of the plant extracts and/or compounds have shown antimicrobial, anti-HIV, hypotensive and photoprotective activities.

Química y Farmacología de Lepidium meyenii Walp ("Maca'')

$Research paper thumbnail of Efecto protector de lÆtex desecado y fracciÛn alcaloidea de Croton palanostigma frente a injuria de mucosa gÆstrica inducida por etanol en ratas$

Efecto protector de lÆtex desecado y fracciÛn alcaloidea de Croton palanostigma frente a injuria de mucosa gÆstrica inducida por etanol en ratas

RESUMEN OBJETIVOS: Evaluar el grado de protección de necrosis de la mucosa gástrica por etanol, c... more RESUMEN OBJETIVOS: Evaluar el grado de protección de necrosis de la mucosa gástrica por etanol, con látex desecado y fracciones alcaloideas de C. palanostigma, en un modelo experimental estandarizado en ratas. Evaluar toxicidad subcrónica. MATERIAL Y MÉTODOS: Se evaluó 60 animales, administrándoles uno de 6 pretratamientos: solución salina, látex desecado de C. palanostigma 120 mg/kg, fracción alcaloidea de C. palanostigma 20 mg/kg, 35 mg/kg y 50 mg/kg y sucralfato 500 mg/kg. Una hora más tarde se aplicó por vía intragástrica 2 mL de etanol al 100%. Se realizó evaluación macroscópica y microscópica de las lesiones gástricas. Se evaluó la toxicidad subcrónica a la dosis de 0,12, 0,40 y 1,20 mL/kg, por el período de 30 días, con estudios bioquímicos e histopatológicos de los órganos. RESULTADOS: El pretratamiento con látex y las fracciones alcaloideas y el sucralfato redujo significativamente la necrosis hemorrágica inducida por el etanol. La toxicidad subcrónica en la dosis mayor mostró riesgo de esteatosis hepática. CONCLUSIÓN: En nuestras condiciones experimentales el C. palanostigma y la taspina presentaron importante efecto protector y potencial terapéutico. En toxicidad subcrónica, la dosis mayor presentó riesgo de esteatosis hepática. Palabras claves: Mucosa gástrica; Plantas medicinales; Agentes antiulcerosos; Modelos animales de enfermedad. PROTECTIVE EFFECT OF DRIED SAP AND ALKALOID FRACTION OF Croton palanostigma AGAINST ACUTE ETHANOL-INDUCED GASTRIC MUCOSA INJURY SUMMARY OBJECTIVE: The gastric protective abilities of dried sap and alkaloid fraction of Croton palanostigma and sucralfate against ethanol-induced necrosis was compared by means of standard experimental rat model. Subchronic toxicity was determined. MATERIAL AND METHODS: A pretreatment with either saline solution, dried sap of C. palanostigma 120 mg/kg, alkaloid fraction of C. palanostigma 20 mg/kg, 35 mg/kg y 50 mg/kg or sucralfate was given to 60 rats. Intragastric administration of 2 mL of 100% ethanol was accomplished one hour later. A gastrectomy was perfomed four hours later followed by macroscopic and histological evaluation of the gastric lesions. Subchronic toxicity was determined with doses of 0,12, 0,40 and 1,20 mL/kg of sap for a 30-day period with biochemical and histopathologic study of the organs. RESULTS: Pretreatment with dried sap and alkaloid fractions of C. palanostigma and sucralfate resulted in a significant reduction of ethanol-induced gastric mucosa necrosis. Subchronic toxicity with C. palanostigma largest dose showed risk of liver steatosis. CONCLUSION: In the present study, dried sap and alkaloid fraction of C. palanostigma and sucralfate showed a significative protective effect, being potentially useful as a therapeutic tool. Subchronic toxicity in higher doses showed risk of liver steatosis.

El género wernería y sus metabolitos secundarios

Revista De Quimica, Feb 20, 2013

El género wernería y sus metabolitos secundarios

Revista De Quimica, Feb 20, 2013

Compendium of Medicinal and Aromatic Plants- The Americas

TOVAR Torres, Doraliza. Líquenes fijadores de nitrógeno atmosférico y sus ficobiontes en cultivo. Lima : CONCYTEC, 1996. 157 p

Revista De Quimica, Apr 1, 2013

Esta obra está dirigida a científicos del área de biología, química, agronomía y personas interes... more

Moléculas que endulzan

Revista De Quimica, Feb 22, 2013

La Revista de la Sociedad Química del Perú: 75 Aniversario

Revista De La Sociedad Quimica Del Peru, 2009

QUIMICA 25 AÑOS DE REALIZACIONES

by NADIA GAMBOA and Olga Lock

$Research paper thumbnail of Protective effect of dried latex and alkaloid fraction of Croton palanostigma against gastric mucosal injury induced by ethanol in rats$

Protective effect of dried latex and alkaloid fraction of Croton palanostigma against gastric mucosal injury induced by ethanol in rats

Estudio químico-farmacológico de la werneria poposa philippi

Boletin De La Sociedad Quimica Del Peru, 1998

Sing de Ugaz, O.L., Colorantes Naturales. Lima, Perú., Fondo Editorial, 1997. 274p

Boletín de la Sociedad Química del Perú, 1997

Química y Farmacología de Smallanthus sonchifolius (Poepp.) H. Rob. ("Yacón")

This review article covers the present knowledge on the chemistry and biological activities of Sm... more This review article covers the present knowledge on the chemistry and biological activities of Smallanthus sonchifolius (Poepp.) H. Rob. A description of the chemical compounds reported in the scientific literature (i.e. oligofructans, phenolic compounds and terpenes) is included. The biological activities of the crude extracts of leaves and roots from yacon are discussed.

Article Antioxidant Bibenzyl Derivatives from Notholaena nivea Desv

Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-gui... more Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-guided fractionation of a CHCl 3-MeOH extract of Notholaena nivea Desv. (Pteridaceae) aerial parts. The structures were elucidated by NMR, ESIMS and other spectral analyses. Their antioxidative effects towards superoxide, lipidic peroxidation and the 2,2'-azino-bis-3-ethilbenzothiazoline-6-sulfonic acid (ABTS) radical were assayed. Results showed that the compound 3,12-dihydroxy-5-methoxybibenzyl (6) is the most active compound in the ABTS free-radical scavenging test, while in the coupled oxidation of β-carotene and linoleic acid assay the compound 5,12-dihydroxy-3-methoxydibenzyl-6carboxylic acid (1) exerted the highest activity after 1h. A superoxide anion enzymatic test was also carried out and the results were confirmed by an inhibition of xanthine oxidase activity assay. The putative protective role played by compounds 1 and 6 on the injurious effects of reactive oxygen metabolites on the intestinal epithelium, using a Caco-2 human cell line, was investigated. H 2 O 2-induced alterations were prevented by preincubating the cells with compounds 1 and 6.

Química y Farmacología del Piper aduncum L. ("Matico")

This review article covers the present knowledge on the chemistry and biological activities of Pi... more This review article covers the present knowledge on the chemistry and biological activities of Piper aduncurn and its synonyms P. angustifoliurn and P. elongaturn. More than 50 compounds have been isolated from these species, which can be grouped as chromenes, phenylpropanoids, benzoic acid derivatives and flavonoids. The biological activities of the crude extracts, and the compounds isolated from them, are discussed. Palabras claves: Piper aduncum, matico, antim icrobiano, Piper angustifolium, Piper elongatum

Química y Farmacología de Physalis peruviana L. (''Aguaymanto'')

This review article covers the present knowledge on the chemistry and biological activities of Ph... more

Revalorizando el uso milenario del sacha inchi (Plukenetia volubilis L.) para la nutrición, la salud y la cosmética

Química y farmacología del Croton lechleri Muell.Arg., ("Sangre de grado")

La presente publicacion pretende dar una vision del conocimiento cientifico quimico- biologico de... more La presente publicacion pretende dar una vision del conocimiento cientifico quimico- biologico del Croton lechleri Muell. Arg., "sangre de grado", esperando asi brindar un aporte para su mejor conocimiento y aprovechamiento. Del Croton lechleri se han reportado constituyentes quimicos como alcaloides, fenolicos, diterpenos y esteroides. Asimismo, los reportes cientificos indican que se han realizado diversos ensayos biologicos para evaluar su actividad antimicrobiana, antioxidante, antimutagen ica, citotoxica, anti inflamatoria, inmunomoduladora y cicatrizante. Se discuten los resultados reportados.

Federación Latinoamericana de Asociaciones Químicas

Chemistry International -- Newsmagazine for IUPAC, 2013

T he Federación Latinoamericana de Asociaciones Químicas (FLAQ) is the representative body for sc... more T he Federación Latinoamericana de Asociaciones Químicas (FLAQ) is the representative body for scientific partnerships and/or chemical professionals of the nations of Latin America. Founded in 1959, FLAQ promotes exchanges between higher educational institutions to respond to urgent development responsibilities in Latin America, encourages research and international meetings on chemical problems, generates media coverage of advances in chemistry, and organizes the Latin American Chemistry Congress. Different types of groups belong to the FLAQ. In some countries, such as Bolivia,

Phytochemistry and biological activities of Werneria and Xenophyllum species

Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are us... more Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are used in traditional medicine of Latin America for the treatment of mountain sickness, hypertension and gastrointestinal disorders. Only a small number of species of these genera have been studied, leading to the isolation of compounds belonging to the classes of benzofurans, chromenes, acetophenones, coumarates, diterpenes and pyrrolizidine alkaloids. Some of the plant extracts and/or compounds have shown antimicrobial, anti-HIV, hypotensive and photoprotective activities.

Química y Farmacología de Lepidium meyenii Walp ("Maca'')

$Research paper thumbnail of Efecto protector de lÆtex desecado y fracciÛn alcaloidea de Croton palanostigma frente a injuria de mucosa gÆstrica inducida por etanol en ratas$

Efecto protector de lÆtex desecado y fracciÛn alcaloidea de Croton palanostigma frente a injuria de mucosa gÆstrica inducida por etanol en ratas

RESUMEN OBJETIVOS: Evaluar el grado de protección de necrosis de la mucosa gástrica por etanol, c... more RESUMEN OBJETIVOS: Evaluar el grado de protección de necrosis de la mucosa gástrica por etanol, con látex desecado y fracciones alcaloideas de C. palanostigma, en un modelo experimental estandarizado en ratas. Evaluar toxicidad subcrónica. MATERIAL Y MÉTODOS: Se evaluó 60 animales, administrándoles uno de 6 pretratamientos: solución salina, látex desecado de C. palanostigma 120 mg/kg, fracción alcaloidea de C. palanostigma 20 mg/kg, 35 mg/kg y 50 mg/kg y sucralfato 500 mg/kg. Una hora más tarde se aplicó por vía intragástrica 2 mL de etanol al 100%. Se realizó evaluación macroscópica y microscópica de las lesiones gástricas. Se evaluó la toxicidad subcrónica a la dosis de 0,12, 0,40 y 1,20 mL/kg, por el período de 30 días, con estudios bioquímicos e histopatológicos de los órganos. RESULTADOS: El pretratamiento con látex y las fracciones alcaloideas y el sucralfato redujo significativamente la necrosis hemorrágica inducida por el etanol. La toxicidad subcrónica en la dosis mayor mostró riesgo de esteatosis hepática. CONCLUSIÓN: En nuestras condiciones experimentales el C. palanostigma y la taspina presentaron importante efecto protector y potencial terapéutico. En toxicidad subcrónica, la dosis mayor presentó riesgo de esteatosis hepática. Palabras claves: Mucosa gástrica; Plantas medicinales; Agentes antiulcerosos; Modelos animales de enfermedad. PROTECTIVE EFFECT OF DRIED SAP AND ALKALOID FRACTION OF Croton palanostigma AGAINST ACUTE ETHANOL-INDUCED GASTRIC MUCOSA INJURY SUMMARY OBJECTIVE: The gastric protective abilities of dried sap and alkaloid fraction of Croton palanostigma and sucralfate against ethanol-induced necrosis was compared by means of standard experimental rat model. Subchronic toxicity was determined. MATERIAL AND METHODS: A pretreatment with either saline solution, dried sap of C. palanostigma 120 mg/kg, alkaloid fraction of C. palanostigma 20 mg/kg, 35 mg/kg y 50 mg/kg or sucralfate was given to 60 rats. Intragastric administration of 2 mL of 100% ethanol was accomplished one hour later. A gastrectomy was perfomed four hours later followed by macroscopic and histological evaluation of the gastric lesions. Subchronic toxicity was determined with doses of 0,12, 0,40 and 1,20 mL/kg of sap for a 30-day period with biochemical and histopathologic study of the organs. RESULTS: Pretreatment with dried sap and alkaloid fractions of C. palanostigma and sucralfate resulted in a significant reduction of ethanol-induced gastric mucosa necrosis. Subchronic toxicity with C. palanostigma largest dose showed risk of liver steatosis. CONCLUSION: In the present study, dried sap and alkaloid fraction of C. palanostigma and sucralfate showed a significative protective effect, being potentially useful as a therapeutic tool. Subchronic toxicity in higher doses showed risk of liver steatosis.

El género wernería y sus metabolitos secundarios

Revista De Quimica, Feb 20, 2013

El género wernería y sus metabolitos secundarios

Revista De Quimica, Feb 20, 2013

Compendium of Medicinal and Aromatic Plants- The Americas

TOVAR Torres, Doraliza. Líquenes fijadores de nitrógeno atmosférico y sus ficobiontes en cultivo. Lima : CONCYTEC, 1996. 157 p

Revista De Quimica, Apr 1, 2013

Esta obra está dirigida a científicos del área de biología, química, agronomía y personas interes... more

Moléculas que endulzan

Revista De Quimica, Feb 22, 2013

La Revista de la Sociedad Química del Perú: 75 Aniversario

Revista De La Sociedad Quimica Del Peru, 2009

Revalorizando el uso milenario del sacha inchi (Plukenetia volubilis L) para la nutrición, la salud y la cosmética

Revista De Fitoterapia, 2013