scholarly journals Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid

2015 ◽  
Vol 71 (4) ◽  
pp. 262-265 ◽  
Author(s):  
Subramanya Pingali ◽  
James P. Donahue ◽  
Florastina Payton-Stewart
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Racemic Mixture ◽  
Inversion Center ◽  
Intermolecular Hydrogen Bonds ◽  
Naturally Occurring ◽  
Pharmacologically Active

Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole –CH2...OCH3and –OCH3...OCH3interactions between neighboring molecules.

A Curious Case of Partial Spontaneous Resolution on Crystallization of a Racemate. The Crystal and Molecular Structures of N-Acetyl-DL-alanine Methylester and iV-Acetyl-L-alanine Methylester

2001 ◽  
Vol 56 (9) ◽  
pp. 871-880 ◽  
Author(s):  
Gerhard Müller ◽  
Martin Lutz
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Spontaneous Resolution ◽  
Racemic Mixture ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds ◽  
Space Group ◽  
The Individual ◽  
Opposite Chirality

Abstract N-Acetyl-L-alanine methylester crystallizes in the orthorhombic space group P212121 with one molecule in the asymmetric unit (a = 7.768(1), b = 9.606(1), c = 10.215(2) Å, Z = 4). The individual molecules are linked into infinite strands by intermolecular hydrogen bonds between the amide hydrogen atom as donor and the acetyl oxygen atom as acceptor. The strands run parallel to the crystallographic b axis. The respective racemate, N-acetyl-DL-alanine methylester, crystallizes in the monoclinic space group P 21/n with three molecules in the asymmetric unit (a = 14.442(3), b = 8.467(2), c = 19.336(5) Å, β = 93.68(1)°, Z = 12). Again, the individual molecules are linked into infinite strands by N-H···O= Cacetyl hydrogen bonds which run along the crystallographic a axis. The individual strands are made up of molecules of opposite chirality in a 2:1 ratio. More specifically, one set of strands consists of molecules in the sequence [D, D, L,]∞ while a second set has the sequence [L, L, D]∞ as imposed by the centrosymmetry o f the space group. Thus, although crystals o f N-acetyl-DL-alanine methylester contain equal amounts of the molecules of opposite chirality, the strand formation through intermolecular hydrogen bonds leads to an incom plete resolution of the racemic mixture of molecules within one strand. The reason for the preference of the observed structure o f N-acetyl-DL-alanine methylester over spontaneous resolution is seen in the optimization of hydrogen bonding within one strand versus the overall crystal packing energy. Some principles of the crystallization of achiral molecules, chiral molecules, and racemates are briefly reviewed, as is the phenomenon of spontaneous resolution.

Hydroxy Derivatives of Poststerone and Its Nontrivial 13(14→8)-Abeo-analogues: Synthesis, Crystal Packing, and Intermolecular Hydrogen Bonds

2021 ◽  
Vol 1227 ◽  
pp. 129509
Author(s):  
Rimma G. Savchenko ◽  
Ekaterina S. Mescheryakova ◽  
Kamil Sh. Bikmukhametov ◽  
Arthur R. Tulyabaev ◽  
Lyudmila V. Parfenova ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Intermolecular Hydrogen Bonds ◽  
Derivatives Of

Dicatharanthinium (2R,3R)-tartrate trihydrate

2006 ◽  
Vol 62 (4) ◽  
pp. o1414-o1416
Author(s):  
Sai-Feng Pei ◽  
Cui-Rong Sun ◽  
Mao-Lin Hu ◽  
Yuan-Jiang Pan
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Chair Conformation ◽  
Ring System ◽  
Indole Ring ◽  
Intermolecular Hydrogen Bonds ◽  
Water Solvent ◽  
Planar Conformation ◽  
Solvent Molecules ◽  
Tartrate Anion

The title salt, bis(methyl 3,4-didehydroibogamin-6-ium-18-carboxylate) (2R,3R)-tartrate trihydrate, 2C21H25N2O2 +·C4H4O6 2−·3H2O, contains two catharanthinium cations, a (2R,3R)-tartrate anion and three water solvent molecules. The cation contains an indole ring system with a planar conformation and a seven-membered nitrogen-containing ring with a distorted chair conformation. A network of O—H...O and N—H...O intermolecular hydrogen bonds stabilizes the crystal packing.

scholarly journals trans-Diaquabis[(E)-3-(dimethylamino)-1-(2-pyridyl)prop-2-en-1-one-κ2N1,O]cobalt(II) dinitrate dihydrate

2009 ◽  
Vol 65 (6) ◽  
pp. m633-m633 ◽  
Author(s):  
Jian-Hong Bi
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Inversion Center ◽  
Distorted Octahedral

In the title compound, [Co(C10H12N2O)2(H2O)2](NO3)2·2H2O, the CoIIion, located on an inversion center, istrans-coordinated by twoN,O-bidentate chelating (E)-3-(dimethylamino)-1-(2-pyridyl)prop-2-en-1-one ligands and by two water molecules in a slightly distorted octahedral geometry. Intermolecular O—H...O hydrogen bonds link the cations, anions and water molecules into layers parallel to theacplane. The crystal packing also exhibits weak intermolecular C—H...O hydrogen bonds.

A Comparison of the Enamino Carbonyl Conjugation Efficiency for Hydrogen Bonding Formation in Pyridone and Dihydropyridone Systems

2000 ◽  
Vol 55 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Teresa Borowiak ◽  
Irena Wolska ◽  
Artur Korzański ◽  
Wolfgang Milius ◽  
Wolfgang Schnick ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Steric Hindrance ◽  
Crystal Packing ◽  
Intermolecular Hydrogen Bond ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds

The crystal structures of two compounds containing enaminone heterodiene systems and forming intermolecular hydrogen bonds N-H·O are reported: 1) 3-ethoxycarbonyl-2-methyl-4-pyridone (hereafter ETPY) and 2) 3-ethoxycarbonyl-2-phenyl-6-methoxycarbonyl-5,6-di-hydro-4-pyridone (hereafter EPPY). The crystal packing is controlled by intermolecular hydro­ gen bonds N-H·O = C connecting the heteroconjugated enaminone groups in infinite chains. In ETPY crystals the intermolecular hydrogen bond involves the heterodienic pathway with the highest π-delocalization that is effective for a very short N·O distance of 2.701(9) Å (average from two molecules in the asymmetric unit). Probably due to the steric hindrance, the hydrogen bond in EPPY is formed following the heterodienic pathway that involves the ester C = O group, although π-delocalization along this pathway is less than that along the pyridone-part pathway resulting in a longer N·O distance of 2.886(3) Å

Three novel benzothiazine-fused triazoles as potential centrally acting muscle relaxants

2012 ◽  
Vol 68 (11) ◽  
pp. o475-o480
Author(s):  
Krishnan Ravikumar ◽  
Balasubramanian Sridhar ◽  
Venkatasubramanian Hariharakrishnan ◽  
Awadesh Narain Singh
Keyword(s):  
Hydrogen Bonds ◽  
Muscle Relaxant ◽  
Crystal Packing ◽  
Chair Conformation ◽  
Muscle Relaxants ◽  
Stacking Interactions ◽  
The Novel ◽  
Intermolecular Hydrogen Bonds ◽  
Keto Ester ◽  
Acting Muscle

The structures of the novel triazolobenzothiazines 2,4-dihydro-1H-benzo[b][1,2,4]triazolo[4,3-d][1,4]thiazin-1-one (IDPH-791), C9H7N3OS, (I), a potential muscle relaxant, its benzoyl derivative, 2-(2-oxo-2-phenylethyl)-2,4-dihydro-1H-benzo[b][1,2,4]triazolo[4,3-d][1,4]thiazin-1-one, C20H17N3O4S, (II), and the β-keto ester derivative, ethyl 3-oxo-2-(1-oxo-2,4-dihydro-1H-benzo[b][1,2,4]triazolo[4,3-d][1,4]thiazin-2-yl)-3-phenylpropanoate, C17H13N3O2S, (III), are the first examples of benzothiazine-fused triazoles in the crystallographic literature. The heterocyclic thiazine rings in all three structures adopt a distorted half-chair conformation. Compound (III) exists in thetrans-β-diketo form. Other than N—H...O hydrogen bonds in (I) forming dimers, no formal intermolecular hydrogen bonds are involved in the crystal packing of any of the three structures, which is dominated by C—H...O/N and π–π stacking interactions.

scholarly journals Crystal structure and Hirshfeld surface analysis of the naturally occurring cassane-type diterpenoid, 6β-cinnamoyl-7β-hydroxyvouacapen-5α-ol

2018 ◽  
Vol 74 (3) ◽  
pp. 385-389 ◽  
Author(s):  
K. Osahon Ogbeide ◽  
Rajesh Kumar ◽  
Mujeeb-Ur-Rehman ◽  
Bodunde Owolabi ◽  
Abiodun Falodun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Surface Analysis ◽  
Title Compound ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Π Interactions ◽  
Compound C ◽  
Naturally Occurring

The title compound, C29H36O5, a cassane-type diterpenoid {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihydroxy-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl 3-phenylprop-2-enoate}, was isolated from a medicinally important plant,Caesalpinia pulcherrima(Fabaceae). In the molecule, three cyclohexane rings aretrans-fused and adopt chair, chair and half-chair conformations. In the crystal, molecules are linkedviaO—H...O hydrogen bonds, forming a tape structure along theb-axis direction. The tapes are further linked into a double-tape structure through C—H...π interactions. The Hirshfeld surface analysis indicates that the contributions to the crystal packing are H...H (65.5%), C...H (18.7%), O...H (14.5%) and C...O (0.3%).

3-(3-Pyridylamino)isobenzofuran-1(3H)-one

2006 ◽  
Vol 62 (5) ◽  
pp. o2088-o2089
Author(s):  
Mustafa Odabaşoğlu ◽  
Orhan Büyükgüngör
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Pyridyl Ring ◽  
Intermolecular Hydrogen Bonds ◽  
Π Interactions ◽  
Compound C ◽  
Ring Motif

The crystal packing of the title compound, C13H10O2N2, is stabilized by one N—H...N and two C—H...O intermolecular hydrogen bonds and also by two C—H...π interactions. The N—H...N and C—H...O hydrogen bonds generate an edge-fused R 3 3(19) ring motif and the phthalide section of the molecule is planar. The dihedral angle between the phthalide group and the pyridyl ring is 87.28 (10)°.

scholarly journals Cyclic imides and an open-chain amide carboxylic acid from the facile reaction ofcis-cyclohexane-1,2-carboxylic anhydride with the isomeric monofluoroanilines

2012 ◽  
Vol 68 (7) ◽  
pp. o253-o256 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Amide Group ◽  
Dihedral Angles ◽  
Two Dimensional ◽  
Intermolecular Hydrogen Bonds ◽  
Open Chain ◽  
Hydrogen Bonding Interactions ◽  
Cyclic Imides

The structures of the cyclic imidescis-2-(2-fluorophenyl)-3a,4,5,6,7,7a-hexahydroisoindole-1,3-dione, C14H14FNO2, (I), andcis-2-(4-fluorophenyl)-3a,4,5,6,7,7a-hexahydroisoindoline-1,3-dione, C14H14FNO2, (III), and the open-chain amide acidrac-cis-2-[(3-fluorophenyl)carbamoyl]cyclohexane-1-carboxylic acid, C14H16FNO3, (II), are reported. Cyclic imides (I) and (III) are conformationally similar, with comparable ring rotations about the imide N—Carbond [the dihedral angles between the benzene ring and the five-membered isoindole ring are 55.40 (8)° for (I) and 51.83 (7)° for (III)]. There are no formal intermolecular hydrogen bonds involved in the crystal packing of either (I) or (III). With the acid (II), in which themeta-related F-atom substituent is rotationally disordered (0.784:0.216), the amide group lies slightly out of the benzene plane [the interplanar dihedral angle is 39.7 (1)°]. Intermolecular amide–carboxyl N—H...O hydrogen-bonding interactions between centrosymmetrically related molecules form stacks extending downb, and these are linked acrosscby carboxyl–amide O—H...O hydrogen bonds, giving two-dimensional layered structures which lie in the (011) plane. The structures reported here represent examples of compounds analogous to the phthalimides or phthalanilic acids and have little precedence in the crystallographic literature.

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