Delisea pulchra (cf. fimbriata) Revisited. The Structural Determination of Two New Metabolites From the Red Alga Delisea pulchra

1992 ◽  
Vol 45 (10) ◽  
pp. 1625 ◽  
Author(s):  
R Denys ◽  
JC Coll ◽  
BF Bowden

Two new metabolites (1a) and (2a) have been isolated from the red alga Delisea pulchra . The previously reported metabolites (3)-(7) were also isolated, and the full n.m.r. characterization of (3), (4) and (6) is reported for the first time.

2020 ◽  
Vol 17 (3) ◽  
pp. 206-210
Author(s):  
Ty Viet Pham ◽  
Thang Quoc Le ◽  
Anh Tuan Le ◽  
Hung Quoc Vo ◽  
Duc Viet Ho

A phytochemical investigation of the leaves of Annona reticulata led to the isolation and structural determination of β-sitosterol (1), ent-pimara-8(14),15-dien-19-oic acid (2), ent-pimara- 8(14),15-dien-19-ol (3), quercetin (4), quercetin 3-O-α-L-arabinopyranoside (5), and a mixture of quercetin 3-O-β-D-galactopyranoside (6a) and quercetin 3-O-β-D-glucopyranoside (6b). Of these, compounds 2 and 3 were isolated from the genus Annona for the first time. Compound 3 showed strong cytotoxicity against SK-LU-1 and SW626 cell lines with IC50 values of 17.64 ± 1.07 and 19.79 ± 1.41 μg mL-1, respectively.


Tetrahedron ◽  
2015 ◽  
Vol 71 (29) ◽  
pp. 4817-4820
Author(s):  
Annamária Zana ◽  
Zsuzsanna Hajdú ◽  
Nikoletta Jedlinszki ◽  
Imre Máthé ◽  
György Dombi ◽  
...  

2019 ◽  
Author(s):  
Christopher Jones ◽  
Matthew Asay ◽  
Lee Joon Kim ◽  
Jack Kleinsasser ◽  
Ambarneil Saha ◽  
...  

Here we apply microcrystal electron diffraction (MicroED) to the structural determination of transition metal complexes. We find that the simultaneous use of 300 keV electrons, very low electron doses, and an ultra-sensitive camera allows for the collection of data without cryogenic cooling of the stage. This technique reveals the first crystal structures of the classic zirconocene hydride, colloquially known as “Schwartz’s reagent”, a novel Pd(II) complex not amenable to solution-state NMR or X-ray crystallography, and five other paramagnetic or diamagnetic transition metal complexes.


1995 ◽  
Vol 6 (1) ◽  
pp. 107-123 ◽  
Author(s):  
Vincenzo G. Albano ◽  
Francesca Calderoni ◽  
Maria Carmela Iapalucci ◽  
Giuliano Longoni ◽  
Magda Monari ◽  
...  

2010 ◽  
Vol 65 ◽  
pp. 168-173
Author(s):  
Marta Ziemnicka ◽  
Bogusław Baś ◽  
Mateusz Jeż ◽  
Ludosław Stobierski

Electrochemical stripping techniques still attract considerable attention for trace metal analysis and for measuring several important organic compounds, due to their unique capabilities of pre-concentrating the analytes at the electrode surface and associated favourable low limits of detection. In this work it is reported for the first time that the Ti(N0,1C0,9), Ti(N0,4C0,6) and Ti(N0,5C0,5) working disc electrodes, a „mercury-free” sensors, offers surprisingly good analytical performance and some valuable properties. The analytical applicability of the Ti(N,C) electrode was confirmed in determination of lead(II) traces in synthetic solutions both with and without surfactants, in certified reference material and in natural water samples. The effects of dissolved oxygen, acids, anions and metal ions were investigated for the Ti(N,C) electrode. Newly prepared and not activated electrode usually cannot be polarized. Therefore, to use the electrode as a voltammetric sensor, its electrochemical activation is required. Composition of conditioning electrolyte and procedures of the electrodes activation were optimized. The fabrication and the response performance of the investigated electrodes were described in the paper. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and transmition electron microscopy (TEM).


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.


1992 ◽  
Vol 45 (10) ◽  
pp. 1611 ◽  
Author(s):  
R Denys ◽  
JC Coll ◽  
BF Bowden

An investigation of the natural products chemistry of the red alga Laurencia mujuscula from the Great Barrier Reef yielded three novel metabolites, (1), (2) and (3a), possessing a new sesquiterpenoid structural type. Known metabolites (6)-(11) were also isolated and the reassignment of n.m.r. spectral values for (11) is reported.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yong-Feng Chen ◽  
Wen-wen Jiang ◽  
Shi-qi Zhang ◽  
Jian-quan Kan ◽  
Yong Liang

As a medicinal and edible fungus parasitizing on the trees, Perigord Truffle (Tuber huidongense) is well known for its delicious taste, unique smell, and high medical value for healthcare. One new water-soluble nonstarch polysaccharide (PST-W with the yield of 0.41%) fromPerigord Truffle(Tuber huidongense) was purified and identified on structural characteristics for the first time. The characterizations of PST-W were studied on physicochemical properties, main components of monosaccharide(s), and molecular structure. The monosaccharide compositions of PST-W were studied and identified as glucan, only containing D-glucoses with the molecular structure of [→6)α-D-Glcp(1→6)  α-D-Glcp (1→]nby methylation analysis and NMR. In the determination of total reducing capacity, the reducing abilities of polysaccharide extracts could be listed as vitamin C > PST-W > crude polysaccharides-3 > crude polysaccharides-2 > crude polysaccharides-1. All of PST-W, crude polysaccharides-2, and crude polysaccharides-3 were relatively good scavenger for 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radicals with IC50of 2.81, 4.17, and 3.44 mg/mL, respectively. However,O2-∙clearing abilities of PST-W and crude polysaccharides were obviously weaker. The activities of total crude extract were the worst, indicating that the impurities might negatively affect the antioxidant activity. Thus, the separation and purification of polysaccharides were significant to increase the antioxidant activity in some degree.


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