Identification of some L-numbered Lycopodium alkaloids

1990 ◽  
Vol 68 (8) ◽  
pp. 1300-1304 ◽  
Author(s):  
William A. Ayer ◽  
Lois M. Browne ◽  
A. Warren Elgersma ◽  
Peter P. Singer

The pioneering research on Lycopodium alkaloids carried out by R. H. F. Manske and L. Marion led to the characterization of a large number of alkaloids. Many of these alkaloids were designated by numbers preceded by an L (e.g., L1, which has since been shown to be dihydrolycopodine). While the identity of many of these alkaloids has now been established, several remain unreported. We have examined samples of alkaloids L15, L16, L17, L18, L22, L24, L25, L26, L28, L29, L31, and L35, obtained from Marion's collection, by GC–MS and GC–IR, and report herein the identity of these alkaloids and alkaloid mixtures. Most of the samples proved to be mixtures of known alkaloids. Acetylannofoline (5), a component of alkaloid L17, and 5,15-oxidolycopodane (9), a component of alkaloids L28 and L31, are identified for the first time as natural products. A complete listing of the L-numbered alkaloids is provided. Keywords: Lycopodium alkaloids, alkaloids, acetylannofoline, oxidolycopodane.

1993 ◽  
Vol 46 (6) ◽  
pp. 933 ◽  
Author(s):  
R Denys ◽  
JC Coll ◽  
BF Bowden

An investigation of the natural products chemistry of the red alga Laurencia marianensis Yamada, a species whose chemistry has not previously been described in the literature, yielded the new metabolite 1-[(3′S*,3a′lR*,4′R*,7′S*,7a′S*)-7′-bromo-7a′-methyl-3′-(1′-methylethyl)octahydro-1′H-inden-4′-yl] ethanone (1) and the known metabolites deoxyprepacifenol (2) and pacifenol (3). The full n.m.r. characterization of (2) and (3) is reported for the first time.


2015 ◽  
Vol 68 (10) ◽  
pp. 1583 ◽  
Author(s):  
Andrew M. Beekman ◽  
Russell A. Barrow

The syntheses of the fungal metabolites cytosporones A, (±)-C, and N are reported. And the syntheses of cytosporones J and K are described for the first time. The preparation of racemic cytosporone J and racemic cytosporone K, natural products containing the rare 3-isochromanone substructure, was achieved in 8 linear steps with an overall yield of 45 % and 7 linear steps in 46 % yield, respectively, resulting in the complete characterization of these compounds for the first time. The key steps included a recently described homologation of benzoic acid to the analogous phenyl acetate using Birch reductive alkylation conditions, acylation of the appropriate phenyl acetate derivative, and a selective reduction and spontaneous biomimetic lactonization to yield the 3-isochromanone skeleton. The synthesized natural products were evaluated for their biological activity against several clinical strains of human pathogens with all compounds displaying weak antimicrobial activity.


Author(s):  
Arif Nurkanto ◽  
Ghulam Jeelani ◽  
Herbert J. Santos ◽  
Yulia Rahmawati ◽  
Mihoko Mori ◽  
...  

Coenzyme A (CoA) is a well-known cofactor that plays an essential role in many metabolic reactions in all organisms. In Plasmodium falciparum, the most deadly among Plasmodium species that cause malaria, CoA and its biosynthetic pathway have been proven to be indispensable. The first and rate-limiting reaction in the CoA biosynthetic pathway is catalyzed by two putative pantothenate kinases (PfPanK1 and 2) in this parasite. Here we produced, purified, and biochemically characterized recombinant PfPanK1 for the first time. PfPanK1 showed activity using pantetheine besides pantothenate, as the primary substrate, indicating that CoA biosynthesis in the blood stage of P. falciparum can bypass pantothenate. We further developed a robust and reliable screening system to identify inhibitors using recombinant PfPanK1 and identified four PfPanK inhibitors from natural compounds.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
KR Gustafson ◽  
STS Chan ◽  
D Milanowski

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.


2020 ◽  
Vol 17 ◽  
Author(s):  
Biswajit Panda ◽  
Amal Kumar Gooyee

: Oceans can play a major role in supplying life-saving medicines in the world in future. Although considerable progress has been made in finding new medicines from marine sources, large efforts are still necessary to examine such molecules for clinical applications. Xyloketals are an important group of natural products with various powerful and prominent bioactivities such as inhibition of acetylcholine esterase, antioxidant activity, inhibition of L-calcium channels, radicalscavenging behavior, suppression of cell proliferation, reduction of neonatal hypoxic-ischemic brain injury, etc. This review describes the isolation and structural characterization of all xyloketal natural products giving major emphasis on their bioactivity.


2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.


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