Encecalol angelate, an unstable chromene from Ageratum conyzoides L.: Total synthesis and investigation of its antiprotozoal activity

Harel, Dipak; Khalid, Sami A.; Kaiser, Marcel; Brun, Reto; Wünsch, Bernhard; Schmidt, Thomas J.

doi:10.1016/j.jep.2011.06.015

Cited by 37 publications

(36 citation statements)

References 18 publications

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“…Their chemical structures were established by physical data and 1D and 2D-NMR spectroscopy, and their spectral data were in agreement with published data (Steelink and Marshall, 1979;Fang et al, 1988;Zhai et al, 2010;Harel et al, 2011).…”

Section: Resultssupporting

confidence: 81%

“…The 1D and 2D-NMR spectral data of these compounds are consistent with those of a chromene skeleton. Thus, compounds 1, 2, 3 and 4 were identified as 6-acetyl-7-hydroxy-2,2-dimethylchromene (eupatoriochromene) (Harel et al, 2011), 6-acetyl-7-methoxy-2,2-dimethylchromene (methyleupatoriochromene) (Zhai et al, 2010), 6-(1-hydroxyethyl)-7-methoxy-2,2-dimethylchromene (encecalinol) (Fang et al, 1988) and 6-(1-ethoxyethyl)-7-methoxy-2,2-dimethylchromene (ethyl encecalol) (Steelink and Marshall, 1979), respectively. There are no spectroscopic or optical evidences to define the absolute stereochemistry of C-11 from compounds 3 and 4.…”

Section: Resultsmentioning

confidence: 99%

“…Several studies have demonstrated the insecticidal, antibacterial, fungicidal and cytotoxic activities of these substances (Bandara et al, 1992;Burkhardt et al, 1994;Iqbal et al, 2004;Chen et al, 2005). Furthermore, some compounds of this class of natural products have been described to have notable antiprotozoal effect (Alizadeh et al, 2008;Batista Jr. et al, 2008;Harel et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the isolated compounds were selected for leishmanicidal assays based on previously reported activity of related structurally compounds in other trypanosomatid protozoa (Harel et al, 2011 …”

Section: Introductionmentioning

confidence: 99%

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Chromenes from leaves of Calea pinnatifida and evaluation of their leishmanicidal activity

Lima

Santos

Costa

et al. 2015

Revista Brasileira de Farmacognosia

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BJP 88 1-4 Revista Brasileira de Farmacognosia xxx (2015) xxx-xxx w w w . s b f g n o s i a . o r g . b r / r e v i s t a a b s t r a c t Calea pinnatifida (R. Br.) Less., Asteraceae, is popularly known as "quebra-tudo", "cipó-cruz" or "aruca". This species is used in the folk medicine for the treatment of stomach pain, giardiasis and amoebiasis. The aim of this study was to isolate and identify chromenes from leaves of C. pinnatifida and evaluate their leishmanicidal activity. A fraction from leaves of C. pinnatifida was analyzed for their chemical constituents, resulting in the isolation and characterization of four known chromenes: 6-acetyl-7-hydroxy-2,2-dimethylchromene (1), 6-acetyl-7-methoxy-2,2-dimethylchromene (2), 6-(1-hydroxyethyl)-7-methoxy-2,2-dimethylchromene (3) and 6-(1-ethoxyethyl)-7-methoxy-2,2-dimethylchromene (4). Structure identification of isolated compounds involved analysis of spectral data of 1D and 2D-NMR. The isolated compounds are here reported for the first time in C. pinnatifida, and the chromenes 1 and 3 show a moderate leishmanicidal activity.

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Section: Resultssupporting

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Chromenes from leaves of Calea pinnatifida and evaluation of their leishmanicidal activity

Lima

Santos

Costa

et al. 2015

Revista Brasileira de Farmacognosia

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“…Various pharmacological and biological uses of this plant or plant-parts have been investigated by many researches. They have reported the tissue repair and collagen formation (Arulprakash et al, 2012), anticancer and antiradical scavenging (Adebayo et al, 2010), ovicidal and larvicidal (Wabo Poné et al, 2011;de Mendonça et al, 2005), antiprotozoan (Harel et al, 2011;Nour et al, 2010), antiaflatoxigenic and antioxidant (Patil et al, 2010), anticoccidial (Nweze and Obiwulu, 2009), haematopoietic (Ita et al, 2007), in vitro antihelicobacter pylori (Ndip et al, 2007), antibacterial and wound healing (Chah et al, 2006), analgesic and antiinflamamtory (Moura et al, 2005), antitumour (Rosangkima and Prashad, 2004), gastroprotective (Shirwaikar et al, 2003) and anti-rheumatism (Chopra et al, 2002) effects of A. conyzoides. In Trinidad and Tobago, this plant has been used in fertility problem of female and erectile dysfunction of male (Lans, 2007).…”

Section: Introductionmentioning

confidence: 99%

Antidiarrheal and antidiabetic effect of ethanol extract of whole Ageratum conyzoides L. in albino rat model

Rahman¹

2013

Afr. J. Pharm. Pharmacol.

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Ageratum conyzoides L. (Asteraceae) is a medicinal herb widely used for several diseases although data are unavailable for diarrhea and diabetes. This study investigated the efficacy of orally administrated ethanol extract of A. conyzoides L. on diarrheal and diabetic rat models. Castor oil induced diarrheal model and gastrointestinal motility test models (barium sulfate milk and charcoal suspension) of albino rats were undertaken to measure the antidiarrheal effect. Alloxan induced diabetic model was used for antidiabetic effect. Data were analyzed by one-way analysis of variance (ANOVA) using Tukey's post hoc test for multiple comparisons. The extract reduced the severity of castor oil induced diarrhea with significant (p < 0.01) inhibition of mean defecation numbers 65.89 ± 2.44, 52.1 ± 3.21 and 27.13 ± 4.67% with 2.0, 1.0 and 0.5 g/kg bw of extract, respectively. The number of stools at different hours in treated group was significantly (p < 0.01) decreased as compared to normal control and positive control group (Loperamide, 1.0 mg/kg). Distance of gastrointestinal motility was significantly (p < 0.05) reduced to 38.88 ± 1.06% from control distance 57.25 ± 1.08% in barium sulfate milk model and to 36.34 ± 0.41% from 57.99 ± 0.66% in charcoal suspension model by the highest dose 2.0 g/kg. In a diabetic model, the blood glucose level was decreased 17.6 ± 1.31%, by 2.0 g/kg, which was significant (p < 0.05) compared to that (52.00 ± 1.21%) of positive control (Glimepiride, 4.0 mg/kg). The results demonstrate the marked anti-diarrheal and moderate anti-diabetic role of whole A. conyzoides L. ethanol extract.

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Biosynthesis of Trehangelin in Polymorphospora rubra K07–0510: Identification of Metabolic Pathway to Angelyl‐CoA

et al. 2016

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Trehangelins are trehalose angelates discovered from endophytic actinomycete Polymorphospora rubra K07-0510. We identified the trehangelin biosynthetic gene cluster, including genes that encode a glycoside hydrolase-like protein (thgC), α-amylase (thgD), 3-ketoacyl-ACP synthase III (thgI), 3-ketoacyl-ACP reductase (thgK), enoyl-CoA hydratase (thgH) and acyl transferase (thgJ). Heterologous expression of thgH, thgI, thgJ and thgK confirmed the importance of these genes in the biosynthesis of trehangelin A. Enzymatic activity studies showed that ThgI catalyses the condensation of acetyl-CoA and methylmalonyl-CoA to 2-methylacetoacetyl-CoA (MAA-CoA), ThgK catalyses NADPH-dependent reduction of MAA-CoA to 3-hydroxy-2-methylbutyryl-CoA (HMB-CoA) and ThgH catalyses the dehydration of HMB-CoA to angelyl-CoA (AN-CoA). This is the first report on the elucidation of the enzymatic formation of AN-CoA.

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Encecalol angelate, an unstable chromene from Ageratum conyzoides L.: Total synthesis and investigation of its antiprotozoal activity

Cited by 37 publications

References 18 publications

Chromenes from leaves of Calea pinnatifida and evaluation of their leishmanicidal activity

Chromenes from leaves of Calea pinnatifida and evaluation of their leishmanicidal activity

Antidiarrheal and antidiabetic effect of ethanol extract of whole Ageratum conyzoides L. in albino rat model

Biosynthesis of Trehangelin in Polymorphospora rubra K07–0510: Identification of Metabolic Pathway to Angelyl‐CoA

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