Sequiterpenes from Ageratina tomentella
TL;DR: Ageratina tomentella has been investigated for sesquiterpene lactones, including 11,13-dehydro-8β-tigloyloxy-eleman-12-oic acid as discussed by the authors.
About: This article is published in Phytochemistry.The article was published on 1988-01-01. It has received 12 citations till now. The article focuses on the topics: Ageratina & Tomentella.
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TL;DR: In this article, the carbon-13 NMR data of sesquiterpene lactones were used for structure classification and methods of structure determination, and the most important methods discussed were: mass spectra, infrared, ultraviolet, NMR and X-ray.
Abstract: Publisher Summary This chapter presents the carbon-13 nuclear magnetic resonance (NMR) data of sesquiterpene lactones. The structure classification and methods of structure determination are also described in the chapter. The sesquiterpene lactones are successfully used in chemotaxonomical studies and there are various biological activities of sesquiterpene lactones that form a basis for the structure–activity relation studies. Large numbers of sesquiterpene lactones are isolated from the plant material. The sesquiterpenoids are C15-compounds formed of three isoprenoid units. Based on the biogenetic assumptions, sesquiterpene lactones arise from a common precursor, farnesyl pyrophosphate, by various modes of cyclization followed in many cases by skeletal rearrangements. Their classification in general is based on the carbocyclic skeleton. The combination of various spectral methods is the most common way to determine the structure of the sesquiterpene lactones. The most important methods discussed are: mass spectra, infrared, ultraviolet, NMR, and X-ray. The 13C NMR spectra of sesquiterpene lactones are recorded with proton broad-band decoupling that eliminates the splitting from 13C-lH spin interactions and hence, the 13C signals appear as singlets. The structural assignments of the signals can be determined by chemical shifts, signal multiplicities, relaxation times, or shift reagents.
38 citations
TL;DR: Sesquiterpene lactones would be a candidate as an anti-allergic agent because of the suppression of Ag-stimulated degranulation by these SQTLs is mainly due to the decreased Ca(2+) influx.
24 citations
TL;DR: Agrostophyllin, the first naturally occurring phenanthropyran derivative, was isolated from the orchid Agroophyllum khasiyanum as mentioned in this paper, and it was shown to be a phenotypic indicator of the presence of humans.
13 citations
TL;DR: An algorithm in PROLOG language is wrote, which computes conditional probabilities for finding skeletons types of sesquiterpene lactones in any taxon, using botanic information as input, and the results are accurate enough to allow good skeletons identification, even for the most complex chemical compound.
12 citations
TL;DR: Two steroids (1 and 2), five pentacyclic triperpenoids (3–7), and a new furanosesquiterpene (8) were isolated from the stems of Ximenia americana, family Olacaceae, establishing structures of the compounds by spectral data.
Abstract: Two steroids (1 and 2), five pentacyclic triperpenoids (3–7) and a new furanosesquiterpene (8) were isolated from the stems of Ximenia americana, family Olacaceae. The structures of the compounds were established by spectral data; two-dimensional NMR spectroscopy has been used to assign all 1H and 13C chemical shifts of 8. Compound 8 did not inhibit the growth of HL-60 (human leukemia), HTC-8 (human colon), and MDA-MB-435 (human breast cancer) cell lines.
5 citations
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TL;DR: In this paper, five sesquiterpene Iactones have been isolated from Artemisia tripartita Rydb. ssp. rupicola Beetle.
44 citations
TL;DR: Pegolettia senegalensis has yielded several sesquiterpene lactones, including 8,14-cyclogermacra-1(10), 4,7(11)-trien-6,12-olide with a new carbon skeleton as mentioned in this paper.
40 citations
TL;DR: The structure of the new compound was determined by spectroscopic methods including an attached proton test experiment and CI mass spectrometry as 6,7-dimethoxy-3,5,3′,4′-tetrahydroxyflavone 3-O -apioside as discussed by the authors.
21 citations
TL;DR: In this paper, chemical analysis of Calea berteriana yielded, besides the known flavonoid acacetin and the sesquiterpene lactone calbertolide C, three new guaianolides, desacyl-8-tiglylsubcordatolide A and 8-epi-8 -tigerlylrupicolin A, and two new chromenes, prunichromenes A and B.
16 citations
TL;DR: In this article, the first guaianolide-type sesquiterpene lactones were reported in the genus Calea and the structures of the new compounds were established by chemical and spectroscopic methods.
15 citations