The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meli... more The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meliaceae), was assayed as a plant-growth inhibitory compound against monocotyledonous and dicotyledonous seeds. This compound inhibited germination, seed respiration, and seedling dry weights of some plant species (Lolium multiflorum, var. Hercules, Triticum vulgare, var. Salamanca, Physalis ixocarpa, and Trifolium alexandrinum). Our results indicate that cedrelanolide interferes with monocot preemergence properties, mainly energy metabolism of the seeds at the level of respiration. In addition, the compound inhibits photophosphorylation, H+ uptake, and noncyclic electron flow. This behavior might be responsible for its plant-growth inhibitory properties and its possible role as an allelopathic agent.
The roots and aerial parts of Tephrosia crassifolia afforded an isopropenyldihydrofuran biflavano... more The roots and aerial parts of Tephrosia crassifolia afforded an isopropenyldihydrofuran biflavanol and a new chalcone. The structures and relative configuration were established by spectroscopic and chemical methods, and confirmed by X-ray diffraction. Crassifolin is the second 3,4″ ether-linked biflavan-4-ol to be isolated from the genus Tephrosia.
American journal of physiology. Renal physiology, 2007
Acute renal failure (ARF) is a clinical syndrome characterized by deterioration of renal function... more Acute renal failure (ARF) is a clinical syndrome characterized by deterioration of renal function over a period of hours or days. The principal causes of ARF are ischemic and toxic insults that can induce tissue hypoxia. Transcriptional responses to hypoxia can be inflammatory or adaptive with the participation of the hypoxia-inducible factor 1alpha and the expression of specific genes related to oxidative stress. The production of peroxynitrites and protein nitrotyrosylation are sequelae of oxidative stress. In several clinical and experimental conditions, inflammatory responses have been related to cyclooxygenase (COX)-2, suggesting that its activation might play an important role in the pathogenesis and progression of nephropathies such as ARF. In the kidney, renin and bradykinin participate on the regulation of COX-2 synthesis. With the hypothesis that in ARF there is an increase in the expression of agents involved in adaptive and inflammatory responses, the distribution patter...
... Chemical volatiles have so many functions: in plant reproduction, attracting pollinators or s... more ... Chemical volatiles have so many functions: in plant reproduction, attracting pollinators or seed dispersers; in chemical defense, repelling insects, avoiding bacterial or fungi phytopathogen colonization, attracting natural enemies of herbivores; or using them like intra and inter ...
The aim of this work was to isolate and identify the antifungal compounds present in the hexanic ... more The aim of this work was to isolate and identify the antifungal compounds present in the hexanic extract of the aerial parts of Gymnosperma glutinosum. The antifungal activity against six pathogenic fungi was determined in accordance with the inhibition of radial growth method. Four of those fungi Aspergillus niger, Candida albicans, Fusarium sporotrichum and Trichophyton mentagrophytes are of clinical importance
We tested the hypothesis that inhibition of EP3 receptors enhances cyclooxygenase (COX)-2 express... more We tested the hypothesis that inhibition of EP3 receptors enhances cyclooxygenase (COX)-2 expression in the thick ascending limb (TAL) induced by hypertonic stimuli. COX-2 protein expression in the outer medulla increased approximately twofold in mice given free access to 1% NaCl in the drinking water for 3 days. The increase was associated with an approximate threefold elevation in COX-2 mRNA accumulation and an increase in PGE2 production by isolated medullary (m)TAL tubules from 77.3 ± 8.4 to 165.7 ± 10.8 pg/mg protein. Moreover, administration of NS-398 abolished the increase in PGE2 production induced by 1% NaCl. EP3 receptor mRNA levels also increased approximately twofold in the outer medulla of mice that ingested 1% NaCl. The selective EP3 receptor antagonist L-798106 increased COX-2 mRNA by twofold in mTAL tubules, and the elevation in COX-2 protein induced by 1% NaCl increased an additional 50% in mice given L-798106. COX-2 mRNA in primary mTAL cells increased twofold in response to media made hypertonic by the addition of NaCl (400 mosmol/kg H2O). L-798106 increased COX-2 mRNA twofold in isotonic media and fourfold in cells exposed to 400 mosmol/kg H2O. PGE2 production by mTAL cells increased from 79.3 ± 4.6 to 286.7 ± 6.3 pg/mg protein after challenge with 400 mosmol/kg H2O and was inhibited in cells transiently transfected with a lentivirus short hairpin RNA construct targeting exon 5 of COX-2 to silence COX-2. Collectively, the data suggest that local hypertonicity in the mTAL is associated with an increase in COX-2 expression concomitant with elevated EP3 receptor expression, which limits COX-2 activity in this segment of the nephron.
The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meli... more The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meliaceae), was assayed as a plant-growth inhibitory compound against monocotyledonous and dicotyledonous seeds. This compound inhibited germination, seed respiration, and seedling dry weights of some plant species (Lolium multiflorum, var. Hercules, Triticum vulgare, var. Salamanca, Physalis ixocarpa, and Trifolium alexandrinum). Our results indicate that cedrelanolide interferes with monocot preemergence properties, mainly energy metabolism of the seeds at the level of respiration. In addition, the compound inhibits photophosphorylation, H+ uptake, and noncyclic electron flow. This behavior might be responsible for its plant-growth inhibitory properties and its possible role as an allelopathic agent.
The roots and aerial parts of Tephrosia crassifolia afforded an isopropenyldihydrofuran biflavano... more The roots and aerial parts of Tephrosia crassifolia afforded an isopropenyldihydrofuran biflavanol and a new chalcone. The structures and relative configuration were established by spectroscopic and chemical methods, and confirmed by X-ray diffraction. Crassifolin is the second 3,4″ ether-linked biflavan-4-ol to be isolated from the genus Tephrosia.
American journal of physiology. Renal physiology, 2007
Acute renal failure (ARF) is a clinical syndrome characterized by deterioration of renal function... more Acute renal failure (ARF) is a clinical syndrome characterized by deterioration of renal function over a period of hours or days. The principal causes of ARF are ischemic and toxic insults that can induce tissue hypoxia. Transcriptional responses to hypoxia can be inflammatory or adaptive with the participation of the hypoxia-inducible factor 1alpha and the expression of specific genes related to oxidative stress. The production of peroxynitrites and protein nitrotyrosylation are sequelae of oxidative stress. In several clinical and experimental conditions, inflammatory responses have been related to cyclooxygenase (COX)-2, suggesting that its activation might play an important role in the pathogenesis and progression of nephropathies such as ARF. In the kidney, renin and bradykinin participate on the regulation of COX-2 synthesis. With the hypothesis that in ARF there is an increase in the expression of agents involved in adaptive and inflammatory responses, the distribution patter...
... Chemical volatiles have so many functions: in plant reproduction, attracting pollinators or s... more ... Chemical volatiles have so many functions: in plant reproduction, attracting pollinators or seed dispersers; in chemical defense, repelling insects, avoiding bacterial or fungi phytopathogen colonization, attracting natural enemies of herbivores; or using them like intra and inter ...
The aim of this work was to isolate and identify the antifungal compounds present in the hexanic ... more The aim of this work was to isolate and identify the antifungal compounds present in the hexanic extract of the aerial parts of Gymnosperma glutinosum. The antifungal activity against six pathogenic fungi was determined in accordance with the inhibition of radial growth method. Four of those fungi Aspergillus niger, Candida albicans, Fusarium sporotrichum and Trichophyton mentagrophytes are of clinical importance
We tested the hypothesis that inhibition of EP3 receptors enhances cyclooxygenase (COX)-2 express... more We tested the hypothesis that inhibition of EP3 receptors enhances cyclooxygenase (COX)-2 expression in the thick ascending limb (TAL) induced by hypertonic stimuli. COX-2 protein expression in the outer medulla increased approximately twofold in mice given free access to 1% NaCl in the drinking water for 3 days. The increase was associated with an approximate threefold elevation in COX-2 mRNA accumulation and an increase in PGE2 production by isolated medullary (m)TAL tubules from 77.3 ± 8.4 to 165.7 ± 10.8 pg/mg protein. Moreover, administration of NS-398 abolished the increase in PGE2 production induced by 1% NaCl. EP3 receptor mRNA levels also increased approximately twofold in the outer medulla of mice that ingested 1% NaCl. The selective EP3 receptor antagonist L-798106 increased COX-2 mRNA by twofold in mTAL tubules, and the elevation in COX-2 protein induced by 1% NaCl increased an additional 50% in mice given L-798106. COX-2 mRNA in primary mTAL cells increased twofold in response to media made hypertonic by the addition of NaCl (400 mosmol/kg H2O). L-798106 increased COX-2 mRNA twofold in isotonic media and fourfold in cells exposed to 400 mosmol/kg H2O. PGE2 production by mTAL cells increased from 79.3 ± 4.6 to 286.7 ± 6.3 pg/mg protein after challenge with 400 mosmol/kg H2O and was inhibited in cells transiently transfected with a lentivirus short hairpin RNA construct targeting exon 5 of COX-2 to silence COX-2. Collectively, the data suggest that local hypertonicity in the mTAL is associated with an increase in COX-2 expression concomitant with elevated EP3 receptor expression, which limits COX-2 activity in this segment of the nephron.
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Papers by Carlos Céspedes