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s ABSTRACT. In order to evaluate the allelochemical activity of some sesqui-terpenes isolated from the native plant Tessaria absinthioides (Hook. et Arn.) DC, and some semi synthetic derivatives against Tenebrio molitor L. larvae, we have... more
s ABSTRACT. In order to evaluate the allelochemical activity of some sesqui-terpenes isolated from the native plant Tessaria absinthioides (Hook. et Arn.) DC, and some semi synthetic derivatives against Tenebrio molitor L. larvae, we have developed bioassays directed to quantify repellency, larval mortality, and its effects on the development. Although costic aldehyde caused the ma-ximum repellent effect, all the compounds showed a significant effect at some dose or time, indicating behavioral avoidance. The topical application of cos-tic aldehyde produced the largest increase on the duration of the pupal stage. Tessaric acid exhibited the highest toxicity by topical application at the experi-ment closure. Both eremophilane–1(10),2,11(13)–triene–12–oic, and γ-costic acids induced some morphological deformities. KEY WORDS. Sesquiterpenes. Tenebrio molitor. Repellency. Development. Mortality. s RESUMEN. Efectos de algunos sesquiterpenos sobre el insecto de produc-tos almacenados, Tene...
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Abstract Batudioic acid, a new labdane type diterpene, was isolated from aerial parts of Baccharis tucumanensis . Its structure was determined by spectral analysis and some chemical transformations. Xan- thomicrol and... more
Abstract Batudioic acid, a new labdane type diterpene, was isolated from aerial parts of Baccharis tucumanensis . Its structure was determined by spectral analysis and some chemical transformations. Xan- thomicrol and scutellarein-7,4′-dimethyl ether were also isolated.
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Abstract A re-examination of Baccharis artemisioides leaves revealed the presence of one new natural product with a clerodane skeleton named deoxybartemidiolide, 15, 16-epoxy-trans-cleroda-3, 13 (16), 14-triene-20, 12S-19, 2 (??)-diolide.... more
Abstract A re-examination of Baccharis artemisioides leaves revealed the presence of one new natural product with a clerodane skeleton named deoxybartemidiolide, 15, 16-epoxy-trans-cleroda-3, 13 (16), 14-triene-20, 12S-19, 2 (??)-diolide. The structure was determined ...
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Abstract A phytochemical examination of the leaves of Zuccagnia punctata resulted in the isolation and identification of 3,7-dihydroxyflavone and 3,7-dihydroxy-8-methoxyflavone. The latter is a new natural product.
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A new grindelane derivative: 2β-hydroxygrindelic acid and the known grindelanes 3β-hydroxygrindelic acid and 6,8(17)-dehydrogrindelic acid were obtained by microbial transformation of sodic grindelate using cultures of Cunninghamella... more
A new grindelane derivative: 2β-hydroxygrindelic acid and the known grindelanes 3β-hydroxygrindelic acid and 6,8(17)-dehydrogrindelic acid were obtained by microbial transformation of sodic grindelate using cultures of Cunninghamella echinulata.
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... JABOROSALACTONE L. A WITHANOLIDE FROM JABOROSA LEUCOTRICHA DAVID LAVIE, HUGO E. GOTTUEB*, MAURICIO J. PESTCHANKERt and OSCAK ... Gan, Israel; tThc Department of Organic Chemistry, Univcrsidad Nacional de San Luis, 786 Gcncral-Paz,... more
... JABOROSALACTONE L. A WITHANOLIDE FROM JABOROSA LEUCOTRICHA DAVID LAVIE, HUGO E. GOTTUEB*, MAURICIO J. PESTCHANKERt and OSCAK ... Gan, Israel; tThc Department of Organic Chemistry, Univcrsidad Nacional de San Luis, 786 Gcncral-Paz, 5700 San ...
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Sesquiterpene lactones constitute a large group of biologically active compounds obtained from plants. The lactones, mexicanin (MXN) and helenalin (HLN), were reported recently as active against the infective form of Trypanosoma cruzi. In... more
Sesquiterpene lactones constitute a large group of biologically active compounds obtained from plants. The lactones, mexicanin (MXN) and helenalin (HLN), were reported recently as active against the infective form of Trypanosoma cruzi. In this work, we studied the effects of these compounds on the growth and viability of the noninfective epimastigote, to compare the sensitivity of the 2 stages and to characterize their actions. Both compounds were cytotoxic to the parasites, with HLN (inhibitory concentration 50% [IC50] 1.9 +/- 0.08 microM) more potent than MXN (IC50 3.8 +/- 0.19 microM) and the typanocidal drug, benznidazole (IC50 8.6 +/- 2.5 microM). The results showed that epimastigotes are less sensitive than trypomastigotes to the compounds. The trypanocidal effect of these lactones, irreversible after 12-hr exposure, was not reversed by the reducing agents dithiotreitol or beta-mercaptoethanol. Ultrastructurally, we observed cytoplasmic vacuolization and nuclear disorganization. Although concentrations between 0.5 and 1.5 microM of the drugs were not lethal to the parasites, epimastigotes became thinner and their nuclei became more pycnotic after exposure. We conclude that MXN and HLN are deleterious for T. cruzi epimastigotes and that their mechanism of action is different than that of the related lactone, dehydroleucodine.
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A series of sesquiterpene compounds possessing both eudesmane and eremophilane skeletons were tested as gastric cytoprotective agents on male Wistar rats. The presence of an alpha,beta-unsaturated aldehyde on the C-7 side chain together... more
A series of sesquiterpene compounds possessing both eudesmane and eremophilane skeletons were tested as gastric cytoprotective agents on male Wistar rats. The presence of an alpha,beta-unsaturated aldehyde on the C-7 side chain together with a hydroxyl group at C-4 is the requirement for the observed antiulcerogenic activity. In an attempt to establish new molecular structural requirements for this gastric cytoprotective activity, a structure-activity study was performed.
Research Interests: Chemistry, Organic Chemistry, Medicine, Animals, Male, and 11 moreStereochemistry, Sesquiterpenes, Rats, Gastrointestinal Tract, Aldehyde, Wistar Rats, Bioorganic and medicinal Chemistry, Biological activity, Structure activity Relationship, Molecular Structure, and Pharmacology and pharmaceutical sciences
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Eight eudesmane and eremophilane sesquiterpenes administered to Tribolium castaneum larvae caused different allelochemical effects. Topical application of 3-oxo-gamma-costic acid produced the greatest lengthening in the duration of the... more
Eight eudesmane and eremophilane sesquiterpenes administered to Tribolium castaneum larvae caused different allelochemical effects. Topical application of 3-oxo-gamma-costic acid produced the greatest lengthening in the duration of the pupal stage. Morphological deformities were found, specifically when ilicic, costic, and gamma-costic acids and costic aldehyde were used. Ilicic acid exhibited the major toxicity 72 hr following topical application. All compounds were significantly toxic at the end point of the experiment (60 days). Treated surface toxicity was lower than when topical assays were carried out. Responses to tessaric acid in choice bioassays had the highest attractive effect. Maximum repellency was caused by the 3-oxo-gamma-costic acid. However, experimental series carried out using gamma-costic acid, eremophilan-1(10),2,11(13)-trien-12-oic acid, costic aldehyde, and ilicic aldehyde showed no clear response.
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From the aerial parts of Laennecia sophiifolia (Kunth) G.L. Nesom, a neo-clerodane and an acyclic furano diterpene were isolated, along with four known compounds, 2beta-hydroxyhardwickiic acid, hawtriwaic acid, apigenin, and... more
From the aerial parts of Laennecia sophiifolia (Kunth) G.L. Nesom, a neo-clerodane and an acyclic furano diterpene were isolated, along with four known compounds, 2beta-hydroxyhardwickiic acid, hawtriwaic acid, apigenin, and beta-sitosterol. Their structures were established as 12-epi-bacchotricuneatin A and (2E,6E)-9-(3-furyl)-6-methyl-2-(4-methylpent-3-enyl)-nona-2,6-dienoic acid, by analysis of spectral evidence. The absolute structure of 12-epi-bacchotricuneatin A was determined by a circular dichroism spectral comparison with that of bacchotricuneatin A.
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The charge (relative concentration) of antioxidants in aqueous extract and dehydroleucodine (DhL) from Artemisia douglasiana Besser was determined employing a procedure based on the quenching of luminol-enhanced chemiluminescence. Total... more
The charge (relative concentration) of antioxidants in aqueous extract and dehydroleucodine (DhL) from Artemisia douglasiana Besser was determined employing a procedure based on the quenching of luminol-enhanced chemiluminescence. Total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) values were determined. The data reported in the present work indicate that the extract of Artemisia douglasiana Besser and DhL showed antioxidant capacity. This activity is more pronounced in the extract, suggesting the presence of several antioxidants in Artemisia douglasiana.
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... E. Sosa,b Juan C. Cesco,E Carlos E. Tonnd & Oscar S. Giordanod ... deterrent activities of twelve clerodane diterpenoids towards Tenebrio molitor (Coleoptera: Tenebrionidae) larvae have been correlated using molecular... more
... E. Sosa,b Juan C. Cesco,E Carlos E. Tonnd & Oscar S. Giordanod ... deterrent activities of twelve clerodane diterpenoids towards Tenebrio molitor (Coleoptera: Tenebrionidae) larvae have been correlated using molecular connectivity indexes ( 3xc, "XI, 'AX) and hydrophobicity ...
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In order to establish structure-activity relationships, nine neo-clerodane diterpenes isolated from the acetone extract of aerial parts of Baccharis flabellata Hook... more
In order to establish structure-activity relationships, nine neo-clerodane diterpenes isolated from the acetone extract of aerial parts of Baccharis flabellata Hook & Arn var. fabellata were assayed for antifeedant activity against Tribolium castaneum (Coleoptera: Tenebrionidae). Compounds exhibiting maximal antifeedant activities showed an alpha,beta-unsaturated carbonyl group on the decalin portion and a furan ring at the side chain. Stereoelectronic studies indicate that the distance between the furan heteroatom and the more electrophilic carbon of the decaline moiety, as well as the electrostatic charge on that atom, were important features for antifeedant activity. Compounds possesing an alpha,beta,gamma,delta-unsaturated carbonyl group or an acetoxyl group at C-2, were inactive. Theoretical calculations were performed in order to find some structure-activity relationships.