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Helvetica Chimica Acta 10/2010; 93(10):1925 - 1932. · 1.48 Impact Factor
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ABSTRACT: Shortly after Sertürner’s isolation of morphine in 1806, which signified the start of plant secondary products research, picrotoxin was isolated
by the French scientist Boullay (1811) from the dried fruits of a liana growing in India and Southeast Asia (1). Although the plant had no value as therapeutic
in Western medicine, picrotoxin was isolated even prior to such therapeutically most important plant constituents as emetine
(1816) and quinine (1820). Its high toxicity and the ease of isolation by crystallization from water were responsible for
the very early discovery of this first member of the picrotoxanes or tutinanolides. Picrotoxanes are a group of sesquiterpenes,
sesquiterpene alkaloids, and “norditerpenes” with highly complex, mostly tetra- or pentacyclic structures and up to 12 stereogenic
centers. Thus, it is not surprising that it took 70 years to learn that the crystalline substance picrotoxin is a molecular
compound consisting of equal amounts of picrotoxinin (1), one of the most potent plant toxins, comparable in lethality with strychnine, and the less active hydrated derivative picrotin
(2). An additional 80 years were to pass until the advent of modern spectroscopy allowed Conroy to complete his pioneering elucidation of the structure of picrotoxinin and picrotin. In the meantime more than ten new structural
relatives had been isolated from very diverse plant families. In 1866, coriamyrtin (9) was isolated from the toxic berries of the tanner’s brush, the only European plant known to contain picrotoxanes.
06/2010: pages 71-210;
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ABSTRACT: Lignans, by convention, are a group of natural products that are formed by linking two phenylpropanoid units (C6C3 units) by oxidative coupling. Most importantly, in a lignan, two (C6C3 units) are bound through the central carbon of their side chains, i.e. the 8 and 8′ positions (1, 2). The occurrence of C6C3-dimers, linked at sites other than the 8–8′ positions, is also known and these compounds have been termed neolignans (3,
4).
06/2010: pages 1-70;
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ABSTRACT: Bioactive microbial metabolites represent powerful tools against both acute and degenerative diseases (96). One of the most
significant fractions within these physiological active compounds is represented by the polyketides. Their pharmaceutical
use takes place in a variety of applications including antibacterials, immunosuppressants, anticancer agents, antifungal drugs,
cholesterol-lowering agents, and products against animal diseases. It is difficult to estimate the magnitude of their advantages,
but the utility of natural products as sources of novel structures still possesses great potential. Thus, in the area of cancer,
in the time frame from around the 1940s to 2006, over 155 small molecules were introduced, of which 73% were other than “synthetics”,
with 47% being either natural products or directly derived there from (28). The overuse of antibiotics has caused bacteria
to become resistant to common drugs. Multiple antibiotic-resistance has emerged as one of the top public health issues worldwide
in the last few decades and has focused attention on the need of new antibiotics (116). Many natural products isolated from
microorganisms or plants are growing in environmental niches (41, 54). Also marine niches have been explored and revealed
new bioactive compounds (13). It seems that natural products are finely tuned for interacting with biological systems and
receptor molecules. They are the result of billions of years of evolution and far surpass anything yet created by humans.
For this reason they represent a superior source of drug candidates or biologically active lead compounds. However, natural
products have not been optimized in evolution as clinical drugs, but rather for their biological functions useful to the producing
organism (36). Due to their variable structures, natural products or derived compounds can fulfill chemical and genetic approaches
for deciphering cellular processes that need not necessarily be a target for therapeutic intervention (125). One great obstacle
for the discovery of new bioactive natural products includes the rediscovery of known compounds at a high frequency. Technical
challenges associated with purification and structure elucidation of the metabolites from microbial fermentations are tricky
and engage microbiologists and chemists. Nevertheless, due to an explosive growth of the sequenced genome number, the potential
of molecular genetics tools together with high-throughput screening systems and other technical advances, natural-product
drug discovery has received new support.
06/2010: pages 211-237;
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Fortschritte der Chemie organischer Naturstoffe. Progress in the chemistry of organic natural products. Progrès dans la chimie des substances organiques naturelles 01/2010; 93:1-70.
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ABSTRACT: A chemical and biological validation of the traditional use of Hyoscyamus niger seeds as anti-inflammatory drug has been established. The methanolic extract of seeds of H. niger (MHN) was evaluated for its analgesic, anti-inflammatory and antipyretic activities in experimental animal models at different doses. MHN produced significant increase in hot plate reaction time, while decreasing writhing response in a dose-dependent manner indicating its analgesic activity. It was also effective in both acute and chronic inflammation evaluated through carrageenin-induced paw oedema and cotton pellet granuloma methods. In addition to its analgesic and anti-inflammatory activity, it also exhibited antipyretic activity in yeast-induced pyrexia model. Furthermore, the bioactive MHN under chemical investigation showed the presence of coumarinolignans as major chemical constituent and yielded a new coumarinolignan, cleomiscosin A methyl ether (1) along with four known coumarinolignans, cleomiscosin A (2), cleomiscosin B (3), cleomiscosin A-9'-acetate (4) and cleomiscosin B-9'-acetate (5). The structure elucidation of 1 was done by spectroscopic data interpretation and comparative HPLC analysis. Cleomiscosin A, but not its isomer cleomiscosin B, reduced dry and wet weight of cotton pellet granuloma in mice. This suggests that cleomiscosin A is an important constituent of MHN responsible for anti-inflammatory activity.
Fitoterapia 09/2009; 81(3):178-84. · 1.85 Impact Factor
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ABSTRACT: In addition to the isolation and complete characterisation of a new lignan, hyoscyamal, three other compounds, balanophonin, pongamoside C and pongamoside D have been isolated from the seeds of Hyoscyamus niger. The structures of the compounds were settled on the basis of spectroscopic analysis. This is the first report on the isolation of these compounds from a solanaceous plant.
Natural product research 02/2009; 23(7):595-600. · 1.01 Impact Factor
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ABSTRACT: A new flavonol glycoside, kaempferol 3-O-alpha-L-arabinopyranosyl-7-O-beta-D-glucopyranoside (1), has been isolated from methanol extract of leaves of Datura suaveolens (Solanaceae), along with six other known compounds, which include kaempferol 3-O-alpha-L-arabinopyranoside (2), 3-phenyl lactic acid, 3-(3-indolyl) lactic acid, and its methyl ester, physalindicanol A and physalindicanol B. The structural elucidation of 1 and characterization of the known compounds are based on detailed spectral analysis (ESI-FTICR-MS and 2D-NMR). This is the first report of isolation of these compounds from this plant.
Natural Product Research 12/2006; 20(13):1231-6. · 1.01 Impact Factor
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ABSTRACT: Hyosmin (1) a new lignan has been isolated from the seeds of Hyoscyamus niger L. (Solanaceae), and its structure shown to be the 3-{[(2R)-2-carbomethoxy-2-hydroxy]ethyl}benzoate ester of {(2R,3S,4S)-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-4-[(4-hydroxy-3-methoxyphenyl)methyl]tetrahydrofuran
Journal of Chemical Research 09/2006; 2006(10):675-677. · 0.04 Impact Factor
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ABSTRACT: Hyosgerin, a new optically active coumarinolignan, has been isolated and characterized along with three other coumarinolignans, venkatasin, cleomiscosin A and cleomiscosin B, from the seeds of Hyoscyamus niger L. The structure was determined on the basis of spectroscopic analysis and chemical conversion. The optical properties and absolute stereochemistry of these coumarinolignans have also been studied and discussed.
CHEMICAL & PHARMACEUTICAL BULLETIN 05/2006; 54(4):538-41. · 1.59 Impact Factor
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ChemInform 03/2005; 36(14).
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ABSTRACT: Two new acyl sucroses were isolated from the epigeal parts of Petunia nyctaginiflora Juss. (Solanaceae). Their structures were determined to be 2, 3, 4-tri (5-methylhexanoyl)-alpha-D-glucopyranosyl-beta-D-fructofuranoside (2) and 2, 3, 4-tri (6-methylheptanoyl)-alpha-D-glucopyranosyl-beta-D-fructofuranoside (4) on the basis of chemical and spectroscopic evidence.
Phytochemistry 07/2003; 63(4):485-9. · 3.35 Impact Factor
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ABSTRACT: Two bis-tetrahydrofuran acetogenins, squamocin-O(1) (1) and squamocin-O(2) (2), were isolated from a MeOH extract of seeds of Annona squamosa L. Their structures were determined by spectral means including precursor-ion scanning mass spectral analysis for their aminal derivatives. The configurations at the oxymethine chiral centers were assigned as 12R,15R,16R,19R,20R,23R,24S,28S,36S for 1 and 12S,15R,16R,19R,20R,23R,24S, 28S,36S for 2, based on 1H NMR analysis of their Mosher's ester derivatives and CD data.
Phytochemistry 01/2003; 61(8):999-1004. · 3.35 Impact Factor
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04/2002;
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Natural Product Letters 10/1994; 5(2):117-121.
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ABSTRACT: A series of N-fatty acyl tryptamines, in which the acyl portion ranged from hexadecanoyl to hexacosanoyl, have been characterized in a petrol extract of the seeds of Annona reticulata.
Phytochemistry.
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ABSTRACT: A hexane extract of the stem bark of Polyalthia longifolia furnished nine new clerodane and ent-halimane diterpenes, i.e. 16-hydroxycleroda-4(18),13-dien-16,15-olide, 16-oxocleroda-4(18),13E-dien-15-oic acid, cleroda-4(18),-13-dien-16,15-olide, 16-hydroxy-ent-halima-5(10),13-dien-16,15-olide, 16-oxo-ent-halima-5(10),13E-dien-15-oic acid, ent-halima-1(10),13E-dien-16,15-olide, 16-oxo-ent-halima-5(10),13E-dien-15-oic acid, ent-halima-5(10),13-dien-16,15-olide and ent-halima-5(10),13E-dien-16,15-olide, along with five known clerodane diterpenes. The structures of these compounds were elucidated by spectroscopic methods. The 13E configuration of two of the new ent-halimanes and one of the known clerodanes was firmly established by NOE experiments.
Phytochemistry 38(1):189-194. · 3.35 Impact Factor
