Chromenes and benzofurans from Ageratina glechonophylla
TL;DR: A re-examination of the aerial part of Ageratina glechonophylla yielded spathulenol (1,6-dihydroxy-4(14)-eudesmene) as a natural product as mentioned in this paper.
About: This article is published in Phytochemistry.The article was published on 1989-01-01. It has received 26 citations till now.
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TL;DR: Fourteen sesquiterpenes, three monoterpenes and one diterpene natural product have been isolated from the seeds of Artemisia annua and the possible biogenesis of some of these natural products are discussed by reference to recently reported experimental results for the autoxidation of dihydroartemisinic acid and other terpenoids from Artemisiaannua.
135 citations
TL;DR: This review covers the structures and biological activities of eudesmane-type sesquiterpenoids from the plants of the Asteraceae family.
125 citations
TL;DR: The biological activity of the newly synthesized compounds was examined and some of them were found to possess anticonvulsant and anti‐inflammatory activities.
Abstract: Treatment of 2-bromoacetylbenzofuran (2) with pyridine afforded its corresponding pyridinium bromide 3. The latter salt reacted with some activated alkenes and acetylenes to give the corresponding indolizine derivatives. Treatment of the salt 3 with benzylidenemalononitriles 9 afforded polysubstituted aniline derivatives, however with arylidenecyanothioacetamides 15 it gave the corresponding 4,5-dihydrothiophenes. Bromide 3 also coupled with p-chlorobenzenediazonium salt followed by ammonium acetate to give the corresponding 1,2,4,5-tetrazine derivative. The biological activity of the newly synthesized compounds was examined and some of them were found to possess anticonvulsant and anti-inflammatory activities.
87 citations
TL;DR: In this paper, the same authors showed that 3-Methyl-2-benzofurancarboxylic acid hydrazide reacts with carbon disulfide and pota- ssium hydroxide to give the corresponding potassium carbodithioate salt.
Abstract: 3-Methyl-2-benzofurancarboxylic acid hydrazide (2) reacts with carbon disulfide and pota- ssium hydroxide to give the corresponding potassium carbodithioate salt 3. Treatment of the latter salt with hydrochloric acid, hydrazine hydrate, and with phen- acyl bromide afforded the corresponding 1,3,4-oxadia- zole-5-thione 4, 4-amino-1,2,4-triazole-5-thione 5, and thiazolidine-2-thione 9 derivatives, respectively. The reaction of either 1,3,4-oxadiazole-5-thione 4 or 4-amino-1,2,4-triazole-5-thione 5 with phenacyl bromide resulted in the formation of 1,2,4-triazolo[3, 4-b]-1,3,4-thiadiazine derivative 8. Treatment of compounds 3 or 4 with hydrazonoyl halides 10a–d furn- ished the same 1,3,4-thiadiazol-2-ylidene derivatives 11a–d. The 7-arylhydrazono-1,2,4-triazolo[3,4-b]-1, 3,4-thiadiazine derivatives 12a–d were obtained either by treatment of 4-amino-1,2,4-triazole-5-thione 5 with hydrazonoyl halides 10a–d or by coupling of the 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine derivative 8 with diazonium salts. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:621–627, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20162
62 citations
TL;DR: In this paper, 3-methylbenzofuran-2-yl)-3-oxopropanenitrile (1) with phenyl isothiocyanate was treated with benzaldehyde followed by bromine to obtain 1,3,4-oxadiazole derivative.
Abstract: Treatment of 3-(3-methylbenzofuran-2-yl)-3-oxopropanenitrile (1) with phenyl isothiocyanate afforded the thioacetanilide derivative 3, which when reacted with α-haloketones, α-halodiketones, and hydrazonoyl chlorides gives thiophene, 1,3-oxathiole, and 1,3,4-thiadiazole derivatives 6a,b, 10a,b and 14a–g, respectively. Treatment of 3-methyl-2-benzofurancarboxylic acid hydrazide (15) with benzaldehyde followed by bromine afforded the 1,3,4-oxadiazole derivative 18. Treatment of the acid hydrazide 15 with phenyl isothiocyanate gave the thiosemicarbazide 20. Compound 20 could be converted into 1,3,4-oxadiazole, 1,2,4-triazole-3-thione, and 1,3,4-thiadiazole derivatives 21, 22, and 23, respectively. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:294–300, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20298
33 citations
References
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TL;DR: In this article, the results of an investigation of six Mexican species of the old genus Eupatorium which are now placed in the genera Ageratina, Critonia and Fleischmannia, yields two new sesquiterpenic acids (12 and 16), a cadinane derivative (40) and three sesiquiterpene lactones (41, 57 and 58).
Abstract: Die Untersuchung von sechs mexikanischen Arten der alten Gattung Eupatorium, die jetzt in die Gattungen Ageratina, Critonia und Fleischmannia eingeordnet werden, ergibt zwei neue Sesquiterpensauren (12 und 16), ein Cadinan-Derivat (40) und drei Sesquiterpenlactone (41, 57 und 58). Auserdem werden neben bereits bekannten Verbindungen elf neue Thymolderivate (3–10 und 46–48), vier p-Hydroxyacetophenon-Derivate (21, 26, 30 und 45), drei Benzoesaurebenzylester (35–37), ein Flavanon (54) und ein Lignan (60) isoliert. Die Konstitutionen werden durch spektroskopische Daten sowie durch einige chemische Reaktionen geklart. Die chemotaxonomischen Aspekte werden diskutiert.
Naturally Occurring Terpene Derivatives, 76. On Constituents of the Eupatorium Group
The investigation of six Mexican species of the old genus Eupatorium which are now placed in the genera Ageratina, Critonia and Fleischmannia, yields two new sesquiterpenic acids (12 and 16), a cadinane derivative (40) and three sesquiterpene lactones (41, 57 and 58). In addition besides already known compounds eleven new thymol derivatives (3–10 and 46–48), four p-hydroxy-acetophenone derivatives (21, 26, 30 and 45), three benzyl benzoates (35–37), a flavanone (54) and a lignan (60) are isolated. The structures are established by spectroscopic data as well as by some chemical reactions. The chemotaxonomical aspects are discussed.
114 citations
TL;DR: The investigation of three species of the new genus Kaunia afforded four new guaianolides and four thymol derivatives, and the structures were elucidated by spectroscopic methods.
45 citations
TL;DR: Phytochemical analysis of Encelia species yielded numerous chromene and benzofuran derivatives that are thought to reflect the phylogeny of the genus and paralleled those based on recent morphological and anatomical findings.
12 citations
TL;DR: The aerial part of Eupatorium quadrangulare afforded in addition to known compounds, a possible biosynthetic intermediate, quadrangulin A, of the eudesmanolides found in this species as discussed by the authors.
7 citations