Four new 5 alpha-pregnane-type steroidal alkaloids, hookerianamides L(1), M(2), N(3), and O(4), and a known N-formylchonemorphine (5) have been isolated by acid-base extraction of the dichloromethane extract of Sarcococca hookeriana. The structures of all compounds were determined with spectroscopic techniques and by comparison with literature data. All compounds displayed antileishmanial and antibacterial properties. Compounds 1, 4, and 5 were found to be more potent than standard pentamidine (IC (50) = 9.59 microg/mL) with respect to leishmanicidal activity. The minimum inhibitory concentration of most of the compounds against Bacillus subtilis, Streptococcus minor, and Streptococcus ferus was lower than that of the standard ampicillin.
"The dimethylamino group at C-3 was assigned an α-position based on the 13 C NMR chemical shift of C-3, and the chemical shift and coupling constant of H-3. The resonance of H-3 as a broad singlet indicated that it is equatorially oriented ; in the case of axial orientation it would appear as a multiplet with W 1/2 = >10, as reported in the literature . These data were compared with those reported compound in which the stereochemistry was "
[Show abstract][Hide abstract] ABSTRACT: Bio-assay guided isolation from the plant Sarcococca wallichii Staph. yielded two new steroidal alkaloids: wallichimine A (1) and wallichimine B (2), and five
known ones: sarcodinine (3), N-methylpachysamine A (4), alkaloid C (5), dictyophlebine (6), and sarcorine (7). The structures of the compounds were
determined using mass spectrometry and NMR spectroscopy techniques. The immunomodulatory potential of compounds was evaluated on different
parameters including production of intracellular reactive oxygen species (ROS), nitric oxide (NO) and on proinflammatory cytokine TNF-α. All compounds
were found to be potent inhibitors of intracellular ROS produced from isolated neutrophils, except compound 5, which showed a moderate level of inhibition.
Compounds 2 and 4 potently inhibited the production of NO (67.9% and 62.5% respectively). Compound 2 showed potent suppression on production of
proinflammatory cytokine TNF-α (76.7%). Among all the tested compounds the new compound 2 was found to be the most potent immunosuppressive agent.
This study shows that steroidal alkaloids could be lead compounds for anti-inflammatory drug discovery.
"The compounds responsible for their pharmacological effects are still unknown. Previous studies have shown that pregnane-type alkaloids are the major components of S. hookeriana and possess antibacterial , antileishmanial , antiplasmodial , and cholinesterase inhibitory activities . Osteoarthritis is one of the main symptoms of rheumatism. "
[Show abstract][Hide abstract] ABSTRACT: Fourteen pregnane-type steroidal alkaloids were isolated from the ethanolic extracts of whole Sarcococca hookeriana var. digyna plants. Their structures were elucidated on the basis of spectral data. Three of them were identified as new steroidal alkaloids: (20S)-20-(N,N-dimethylamino)-16α,17α-epoxy-3β-methoxy-pregn-5-ene (1), (20S)-20-(N,N-dimethylamino)-3β-tigloylamino-5α-pregn-11β-ol (2), and (20S)-2α,4β-bis(acetoxy)-20-(N,N-dimethylamino)-3β-tigloylamino-5α-pregnane (3). Some of the isolated compounds showed estrogen biosynthesis-promoting effects in human ovarian granulosa-like KGN cells. The EC50 values for the most effective compounds, vagnine B (6) and (20S)-20-(N, N-dimethylamino)-5α-pregnane (12), were 71 μM and 67 μM, respectively.
[Show abstract][Hide abstract] ABSTRACT: Plant steroids constitute a diverse group of natural products. Biosynthetically, they are derived from S-squalene-2,3-epoxide via acetate-mevalonate pathway. Among the plant steroids, phytosterols are ubiquitous in the plant kingdom. It is significant that some phytosterols have been reported to possess hypocholesterolemic activity. Withanolides are a large group of steroidal lactones with various biological activities. Brassinosteroids are a small group of plant steroids exhibiting plant growth hormonal activity. Phytoecdysteroids are polyhydroxylated plant steroids, many of which are known to exhibit anabolic effects with no undesirable side effects. Steroidal alkaloids are nitrogen-containing plant steroids with an array of biological activities. It is noteworthy that trace amounts of cholesterol and mammalian steroidal hormones including progesterone have been detected in some plants. Analyses of plant steroids mainly utilize chromatographic methods such as thin-layer chromatography (TLC), high performance liquid chromatography (HPLC), ultra high performance liquid chromatography (UHPLC), and gas liquid chromatography (GLC), while photodiode array (PDA), evaporative light scattering (ELS), and fluorescence (FL) detectors and mass spectrometry (MS) are commonly used for their detection, quantification, and identification. Some less common techniques employed for the analyses of plant steroids are immunoassays and biological assays.Keywords:plant steroids;occurrence;biological activity;analysis;thin-layer chromatography;high performance liquid chromatography;gas liquid chromatography;mass spectroscopy;biological assay;immunoassay
Encyclopedia of Analytical Chemistry, 06/2014: pages 1-26; , ISBN: 9780471976707
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