Olga Lock | Pontificia Universidad Catolica del Peru (original) (raw)

Books by Olga Lock

Papers by Olga Lock

Boletin De La Sociedad Quimica Del Peru, 1998

Boletín de la Sociedad Química del Perú, 1997

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.

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.

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

This review article covers the present knowledge on the chemistry and biological activities of Ph... more This review article covers the present knowledge on the chemistry and biological activities of Physalis peruviana L.A description of the chemical compounds reported in the scientific literature is included. The biological activities of the crude extracts and pure compounds are discussed.

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.

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,

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.

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.

Revista De Quimica, Feb 20, 2013

Revista De Quimica, Feb 20, 2013

Revista De Quimica, Apr 1, 2013

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

Revista De Quimica, Feb 22, 2013

Revista De La Sociedad Quimica Del Peru, 2009

Boletin De La Sociedad Quimica Del Peru, 1998

Boletín de la Sociedad Química del Perú, 1997

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.

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.

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

This review article covers the present knowledge on the chemistry and biological activities of Ph... more This review article covers the present knowledge on the chemistry and biological activities of Physalis peruviana L.A description of the chemical compounds reported in the scientific literature is included. The biological activities of the crude extracts and pure compounds are discussed.

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.

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,

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.

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.

Revista De Quimica, Feb 20, 2013

Revista De Quimica, Feb 20, 2013

Revista De Quimica, Apr 1, 2013

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

Revista De Quimica, Feb 22, 2013

Revista De La Sociedad Quimica Del Peru, 2009

Revista De Fitoterapia, 2013