scholarly journals Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

2013 ◽  
Vol 9 ◽  
pp. 1737-1744 ◽  
Author(s):  
James C Anderson ◽  
Andreas S Kalogirou ◽  
Michael J Porter ◽  
Graham J Tizzard
Keyword(s):  
Single Crystal ◽  
Natural Product ◽  
Mannich Reaction ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Set Up

Piperazirum, isolated from Arum palaestinum Boiss, was originally assigned as r-3,c-5-diisobutyl-c-6-isopropylpiperazin-2-one. The reported structure was synthesised diastereoselectively using a key nitro-Mannich reaction to set up the C5/C6 relative stereochemistry. The structure was unambiguously assigned by single crystal X-ray diffraction but the spectroscopic data did not match those reported for the natural product. The structure of the natural product must therefore be revised.

New iboga-type alkaloids from Ervatamia hainanensis

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30277-30284 ◽  
Author(s):  
Zhi-Wen Liu ◽  
Xiao-Jun Huang ◽  
Han-Lin Xiao ◽  
Guo Liu ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray

The structures and absolute configurations of seven new iboga-type alkaloids 1–7 were determined by spectroscopic data, Mosher's method, single crystal X-ray diffraction and ECD analyses.

Mannich Reaction Product of Quinolin-8-ol (Oxine) and its Antibacterial Activity

1997 ◽  
Vol 50 (8) ◽  
pp. 861 ◽  
Author(s):  
Shaheen Faizi ◽  
Bina Shaheen Siddiqui ◽  
Rubeena Saleem ◽  
Farzana Akhtar ◽  
Khursheed Ali Khan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Single Crystal ◽  
Mannich Reaction ◽  
Gram Negative Bacteria ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Screening ◽  
X Ray

Quinolin-8-ol (1) on reaction with 2,6-dichloroaniline and m-nitrobenzaldehyde afforded 7-(α-hydroxy- m-nitrobenzyl)quinolin-8-ol (2), which is an unusual Mannich reaction product. The structure of (2) was determined by spectroscopic and single-crystal X-ray diffraction studies. Preliminary antimicrobial screening showed that (1) and (2) have activity against a large number of Gram-positive and Gram-negative bacteria.

scholarly journals NovelFeIIandCoIIComplexes of Natural Product Tryptanthrin: Synthesis and Binding with G-Quadruplex DNA

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yi-ning Zhong ◽  
Yan Zhang ◽  
Yun-qiong Gu ◽  
Shi-yun Wu ◽  
Wen-ying Shen ◽  
...  
Keyword(s):  
Natural Products ◽  
Ligand Binding ◽  
Single Crystal ◽  
Natural Product ◽  
Significant Interaction ◽  
Rational Design ◽  
X Ray Diffraction ◽  
Quadruplex Dna ◽  
X Ray ◽  
G Quadruplex

Tryptanthrin is one of the most important members of indoloquinoline alkaloids. We obtained this alkaloid fromIsatis. Two novelFeIIandCoIIcomplexes of tryptanthrin were first synthesized. Single-crystal X-ray diffraction analyses show that these complexes display distorted four-coordinated tetrahedron geometry via two heterocyclic nitrogen and oxygen atoms from tryptanthrin ligand. Binding with G-quadruplex DNA properties revealed that both complexes were found to exhibit significant interaction with G-quadruplex DNA. This study may potentially serve as the basis of future rational design of metal-based drugs from natural products that target the G-quadruplex DNA.

New quinolinone alkaloids from the heartwood of, Euxylophora paraensis

1981 ◽  
Vol 34 (8) ◽  
pp. 1625 ◽  
Author(s):  
L Jurd ◽  
RY Wong
Keyword(s):  
Single Crystal ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray

The heartwood of Euxylophora paraensis Hub. (Rutaceae) has given N-methylflindersine (2),spectabiline (3), skimmianine (4) and two new alkaloids, identified from spectroscopic data as 4-hydroxy-2,2,6-trimethyl-3,4,5,6-tetrahydro-2H-pyrano[3,2-c]quinolin-5-one (5) and 4-(2,3-dihydroxy-3-methylbutoxy)-1-methylquinolin-2(1H)-one (6). Five new dimeric quinolinone alkaloids, C30H30N2O4, were isolated. The structure of one of these, paraensidimerin D, has now been shown by single-crystal X-ray diffraction methods to be (11), viz. (6aα,7α,14aα)-6,6,9,16- tetramethyl-7-(2-methylprop-1-enyl)-6,6a,7,9,14a,16-hexahydro-8H,15H- quino[3'',4'':5',6'] pyrano [2',3':4,5] pyrano-[3,2-c]quinoline-8,15- dione.

scholarly journals ISOLATION AND STRUCTURAL ELUCIDATION OF A NEW DEPSIDE OF LICHEN Everniopsis trulla

2021 ◽  
Vol 87 (2) ◽  
pp. 97-106
Author(s):  
Olivio Nino Castro ◽  
Jesús López Rodilla ◽  
Sofia Pombal ◽  
Francisca Sanz González ◽  
Julio Santiago Contreras
Keyword(s):  
Mass Spectrometry ◽  
Melting Point ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Spectroscopic Data ◽  
Intermolecular Forces ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Uv Visible

In this research, a new depside of the lichen Everniopsis trulla has been isolated. The extraction was carried out to 400 g of dry sample and ground with ethanol for 3 repetitions, then, it was fractionated by applying column chromatography with the CHCl3-MeOH system and purified by recrystallization with MeOH-Acetone (1: 1); Finally, white crystals in the form of needles (solid C) with a melting point of 198 ° C were obtained, whose structure was elucidated based on spectroscopic data (UV-Visible, IR, NMR-H1, NMR-C13, mass spectrometry and single crystal X-ray diffraction). According to the Science Finder databases, it is a new depside, called trullarin, and it is observed that molecular packing is influenced by both intramolecular and intermolecular forces. Intermolecular hydrogen bonds of O - H -O type binds neighboring molecules forming dimers.

scholarly journals Crystal structure of 5-[(benzoyloxy)methyl]-5,6-dihydroxy-4-oxocyclohex-2-en-1-yl benzoate

2020 ◽  
Vol 76 (7) ◽  
pp. 1096-1100
Author(s):  
Theerachart Leepasert ◽  
Patchreenart Saparpakorn ◽  
Kittipong Chainok ◽  
Tanwawan Duangthongyou
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Natural Product ◽  
Dihedral Angle ◽  
Absolute Configuration ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ring Form

The crystal structure of the natural product zeylenone, C21H18O7, was confirmed by single-crystal X-ray diffraction. The crystal structure has three chiral centers at positions C1, C5 and C6 of the cyclohexanone ring, but the absolute configuration could not be determined reliably. The methyl benzoate and benzoyloxy substituents at positions C1 and C5 of the cyclohexenone ring are on the same side of the ring with the dihedral angle between their mean planes being 16.25 (10)°. These rings are almost perpendicular to the cyclohexenone ring. The benzoate groups and two hydroxyl groups on the cyclohexenone ring form strong hydrogen bonds to consolidate the crystal structure. In addition, weak C—H...O hydrogen bonds also contribute to the packing of the structure.

scholarly journals Secondary Metabolites with α-Glucosidase Inhibitory Activity from the Mangrove Fungus Mycosphaerella sp. SYSU-DZG01

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 483 ◽  
Author(s):  
Pei Qiu ◽  
Zhaoming Liu ◽  
Yan Chen ◽  
Runlin Cai ◽  
Guangying Chen ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Secondary Metabolites ◽  
Single Crystal ◽  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ic50 Values ◽  
New Metabolites

Four new metabolites, asperchalasine I (1), dibefurin B (2) and two epicoccine derivatives (3 and 4), together with seven known compounds (5–11) were isolated from a mangrove fungus Mycosphaerella sp. SYSU-DZG01. The structures of compounds 1–4 were established from extensive spectroscopic data and HRESIMS analysis. The absolute configuration of 1 was deduced by comparison of ECD data with that of a known structure. The stereostructures of 2–4 were further confirmed by single-crystal X-ray diffraction. Compounds 1, 8 and 9 exhibited significant α-glucosidase inhibitory activity with IC50 values of 17.1, 26.7 and 15.7 μM, respectively. Compounds 1, 4, 6 and 8 showed antioxidant activity by scavenging DPPH· with EC50 values ranging from 16.3 to 85.8 μM.

scholarly journals Anti-inflammatory Anthraquinones from the Crinoid Himerometra magnipinna

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000
Author(s):  
Yen-You Lin ◽  
Su-June Tsai ◽  
Michael Y. Chiang ◽  
Zhi-Hong Wen ◽  
Jui-Hsin Su
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Absolute Configuration ◽  
Spectroscopic Data ◽  
Test Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anti Inflammatory ◽  
Raw264.7 Macrophage

Chemical investigation of a crinoid Himerometra magnipinna has afforded three anthraquinones (1–3), including one new metabolite, (+)-rhodoptilometrin (1). The structures of these compounds were elucidated on the basis of their spectroscopic data and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. In the in vitro anti-inflammatory effects test, compound 2 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS protein of the LPS-stimulated RAW264.7 macrophage cells.

scholarly journals X-ray structure of hexamethyl benzenehexacarboxylate, [C6(COOCH3)6]

1970 ◽  
Vol 34 (2) ◽  
pp. 197-200
Author(s):  
Shishir Ghosh ◽  
Md Kamal Hossain ◽  
Shariff E Kabir ◽  
Noorjahan Begum
Keyword(s):  
Thermal Treatment ◽  
Single Crystal ◽  
Diffraction Study ◽  
Key Words ◽  
Spectroscopic Data ◽  
Monoclinic Space Group ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Academy Of Sciences

The thermal treatment of [Ru2(CO)6(μ-η1,η2-C4H3O){μ-P(C4H3O)2}] 1 with dimethyl acetylenedicarboxylate (DMAD) at 110 °C leads to cyclotrimerization of DMAD. The cyclotrimerization product hexamethyl benzenehexacarboxylate, [C6(COOCH3)6] 2, was obtained in 37% yield and characterized by a combination of spectroscopic data and single crystal X-ray diffraction study. Compound 2 crystallizes in the monoclinic space group P1bar with a = 10.3002(12), b = 11.0371(13), c = 18.781(2) Å, α = 76.148(2), β = 87.390(2), γ = 74.001(2)°, Z = 4 and V = 1992.2(4) Å3. Key words: Cyclotrimerization; Dimethyl acetylenedicarboxylate; X-ray structure DOI: 10.3329/jbas.v34i2.6866Journal of Bangladesh Academy of Sciences, Vol. 34, No. 2, 197-200, 2010

scholarly journals Antioxidant Sesquiterpenes from Penicillium citreonigrum

2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Wei-Hua Yuan ◽  
Ying Zhang ◽  
Peng Zhang ◽  
Ru-Ru Ding
Keyword(s):  
Ascorbic Acid ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Mycophenolic Acid ◽  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antioxidant Capacities

A new chlorinated 11-noreremophilane-type sesquiterpene (1) together with 3-epiisopetasol, PR-amide and mycophenolic acid (2–4) were isolated from endophytic fungus Penicillium citreonigrum. The structures of 1–4 were elucidated by a combination of spectroscopic data and single-crystal X-ray diffraction analysis. Among them, compounds 1 and 4 showed moderate antioxidant capacities compared with ascorbic acid at 0.2 mM concentration.

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