scholarly journals The conversion of cephalosporins to 7 α-methoxycephalosporins by cell-free extracts of Streptomyces clavuligerus

1980 ◽  
Vol 186 (2) ◽  
pp. 613-616 ◽  
Author(s):  
J O'Sullivan ◽  
E P Abraham
Keyword(s):  
Methoxy Group ◽  
Biosynthetic Pathway ◽  
Streptomyces Clavuligerus ◽  
Ring System ◽  
Reducing Agent ◽  
Cephalosporin C ◽  
Methoxy Derivative

In the presence of S-adenosylmethionine, 2-oxoglutarate, Fe2+ and a reducing agent, cell-free extracts of Streptomyces clavuligerus convert cephalosporin C and O-carbamoyldeacetylcephalosporin C into 7 alpha-methoxy derivatives. No synthesis of a 7 alpha-methoxy derivative of deacetylcephalosporin C was detected in the system used, and the 7 alpha-methoxy derivative of deacetoxycephalosporin C was produced only in relatively small amounts. It appears that the 7 alpha-methoxy group is introduced after the cephalosporin ring system has been formed and that its introduction may represent the final step in a biosynthetic pathway.

scholarly journals Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

2014 ◽  
Vol 10 ◽  
pp. 2677-2682 ◽  
Author(s):  
Zhi Kai Guo ◽  
Rong Wang ◽  
Wei Huang ◽  
Xiao Nian Li ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
Biosynthetic Pathway ◽  
Culture Broth ◽  
Ring System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anti Oxidant ◽  
Inhibitory Activities ◽  
Aspergillus Sp

An unusual C18 norditerpenoid, aspergiloid I (1), was isolated from the culture broth of Aspergillus sp. YXf3, an endophytic fungus derived from Ginkgo biloba. Its structure was unambiguously established by analysis of HRMS–ESI and spectroscopic data, and the absolute configuration was determined by low-temperature (100 K) single crystal X-ray diffraction with Cu Kα radiation. This compound is structurally characterized by a new carbon skeleton with an unprecedented 6/5/6 tricyclic ring system bearing an α,β-unsaturated spirolactone moiety in ring B, and represents a new subclass of norditerpenoid, the skeleton of which is named aspergilane. The hypothetical biosynthetic pathway for 1 was also proposed. The cytotoxic, antimicrobial, anti-oxidant and enzyme inhibitory activities of 1 were evaluated.

Three unlinked gene clusters are involved in clavam metabolite biosynthesis in Streptomyces clavuligerus

2004 ◽  
Vol 50 (10) ◽  
pp. 803-810 ◽  
Author(s):  
Kapil Tahlan ◽  
Hyeon Ung Park ◽  
Susan E Jensen
Keyword(s):  
Clavulanic Acid ◽  
Gel Electrophoresis ◽  
Genomic Dna ◽  
Biosynthetic Pathway ◽  
Gene Clusters ◽  
Streptomyces Clavuligerus ◽  
Pulsed Field Gel Electrophoresis ◽  
Single Family ◽  
Chromosome Walking ◽  
Restriction Fragments

In Streptomyces clavuligerus, three groups of genes are known to be involved in the biosynthesis of the clavam metabolites. Since antibiotic biosynthetic genes are invariably clustered on the chromosome in prokaryotes, chromosome walking was undertaken in an attempt to show that the three groups of clavam genes would resolve into a single super-cluster when analyzed at larger scale. However, no evidence of linkage between the three groups was obtained. Furthermore, Southern analysis of macro-restriction fragments of genomic DNA separated by pulsed-field gel electrophoresis also indicated that the three groups of genes are not linked. Despite the structural and biosynthetic relatedness of the clavam metabolites, our results suggest that the genes involved in their production lie in three unlinked gene clusters. We believe that this represents the first instance in bacteria of genes involved in the biosynthesis of a single family of antibiotics sharing a common biosynthetic pathway and yet residing in three separate locations on the chromosome.Key words: Streptomyces, clavulanic acid, clavams, paralogues, gene clusters.

scholarly journals Ethyl 2-amino-4-(4-fluorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carboxylate

2012 ◽  
Vol 68 (6) ◽  
pp. o1803-o1804 ◽  
Author(s):  
Ahmed M. El-Agrody ◽  
Mohamed A. Al-Omar ◽  
Abdel-Galil E. Amr ◽  
Tze Shyang Chia ◽  
Hoong-Kun Fun
Keyword(s):  
Benzene Ring ◽  
Methoxy Group ◽  
Crystal Packing ◽  
Ring System ◽  
Maximum Deviation ◽  
Boat Conformation ◽  
Pyran Ring ◽  
Compound C ◽  
The Mean ◽  
Chromene Ring

In the title compound, C23H20FNO4, the fluoro-substituted benzene ring is approximately perpendicular to the mean plane of the 4H-benzo[h]chromene ring system [maximum deviation = 0.264 (1) Å], with a dihedral angle of 83.79 (6)°. The pyran ring adopts a flattened boat conformation. The methoxy group is slightly twisted from the attached benzene ring of the 4H-benzo[h]chromene moiety [C—O—C—C = −2.1 (2)°]. An intramolecular N—H...O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked by N—H...O and N—H...F hydrogen bonds into a layer parallel to the bc plane. The crystal packing also features C—H...π interactions.

scholarly journals 3-(2-Hydroxy-4-methoxyphenyl)-N-(2-methoxyphenyl)-5-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide

IUCrData ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
Seunghyun Ahn ◽  
Yoongho Lim ◽  
Jiha Sung ◽  
Dongsoo Koh
Keyword(s):  
Hydrogen Bond ◽  
Methoxy Group ◽  
Ring System ◽  
Dihedral Angles ◽  
Naphthalene Ring ◽  
Benzene Rings ◽  
Pyrazoline Ring ◽  
Title Molecule ◽  
Phenol Ring ◽  
Ring Motif

In the title molecule, C28H25N3O3S, the dihedral angles formed by the naphthalene ring system and the benzene rings are 73.03 (13) and 74.04 (11)°. The benzene rings attached to the central pyrazoline ring are almost coplanar, as indicated by the dihedral angle of 2.22 (10)° between them. The C atom of the methoxy group of the phenol ring is essentially coplanar with the ring [C—C—O—C = −0.3 (3)°], whereas the C atom of the methoxy group of the thioamide benzene ring is slightly twisted [C—C—O—C = 5.4 (3)°]. An intramolecular O—H...N hydrogen bond generates anS(6) ring motif. In the crystal, pairs of very weak C—H...S interactions form inversion dimers with anR22(18) motif.

scholarly journals 3-(2-Methoxyphenyl)-2,3-dihydro-1H-benzo[f]chromen-1-one

IUCrData ◽  
2020 ◽  
Vol 5 (9) ◽  
Author(s):  
Jiha Sung
Keyword(s):  
Benzene Ring ◽  
Title Compound ◽  
Methoxy Group ◽  
Ring System ◽  
Pyran Ring ◽  
Envelope Conformation ◽  
Compound C ◽  
Naphthyl Ring

In the title compound, C20H16O3, the 2-methoxyphenyl ring is tilted by 50.67 (3)° with respect to the naphthyl ring system. The central pyran ring has an envelope conformation with the C atom bearing the pendant ring system as the flap. The methoxy group attached to the benzene ring is slightly twisted [C—C—O—C = −15.2 (1)°] from the ring. In the crystal, weak C—H...O interactions link the molecules into C(7) chains propagating along [101].

scholarly journals Crystal structure of 4-methoxyquinazoline

2014 ◽  
Vol 70 (12) ◽  
pp. o1279-o1279
Author(s):  
Gamal A. El-Hiti ◽  
Keith Smith ◽  
Amany S. Hegazy ◽  
Mohammed B. Alshammari ◽  
Benson M. Kariuki
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Methoxy Group ◽  
Ring System ◽  
Axis Direction ◽  
Compound C ◽  
The Mean ◽  
Packing Arrangement

The title compound, C9H8N2O, is almost planar, with the C atom of the methoxy group deviating from the mean plane of the quinazoline ring system (r.m.s. deviation = 0.011 Å) by 0.068 (4) Å. In the crystal, molecules form π–π stacks parallel to theb-axis direction [centroid–centroid separation = 3.5140 (18) Å], leading to a herringbone packing arrangement.

scholarly journals (E)-1-(2-Hydroxy-6-methoxyphenyl)-3-(2-methoxynaphthalen-1-yl)prop-2-en-1-one

IUCrData ◽  
2019 ◽  
Vol 4 (9) ◽  
Author(s):  
Jiha Sung
Keyword(s):  
Hydrogen Bond ◽  
Benzene Ring ◽  
Dihedral Angle ◽  
Title Compound ◽  
Methoxy Group ◽  
Ring System ◽  
Naphthalene Ring ◽  
Compound C ◽  
Phenol Ring ◽  
Ring Motif

In the title compound, C21H18O4, the dihedral angle between the naphthelene ring system (r.m.s. deviation = 0.014 Å) and the benzene ring is 9.68 (1)°. The C atom of the methoxy group of the naphthalene ring system is almost coplanar with the ring [C—O—C—C = −2.0 (3)°], whereas the C atom of the methoxy group of the phenol ring is slightly twisted [C—O—C—C = 6.2 (3)°]. An intramolecular O—H...O hydrogen bond generates an S(6) ring motif.

scholarly journals Crystal structure of 3-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydrocyclopenta[b]indole-2-carboxylic acid

2015 ◽  
Vol 71 (6) ◽  
pp. o395-o396 ◽  
Author(s):  
Daniara Fernandes ◽  
Deborah de Alencar Simoni ◽  
Manoel T. Rodrigues ◽  
Marilia S. Santos ◽  
Fernando Coelho
Keyword(s):  
Carboxylic Acid ◽  
Benzene Ring ◽  
Methoxy Group ◽  
Ring System ◽  
Membered Ring ◽  
Compound C ◽  
Methoxy Groups ◽  
Fused Ring ◽  
The Mean ◽  
Fused Ring System

In the title compound, C21H21NO5, obtained from a Morita–Baylis–Hillman adduct, the hydrogenated five-membered ring adopts a shallow envelope conformation, with the C atom bearing the carboxylic acid substituent deviating by 0.237 (1) Å from the mean plane of the other four atoms (r.m.s. deviation = 0.007 Å). The dihedral angle between the fused ring system (all atoms; r.m.s. deviation = 0.057 Å) and the pendant trimethoxy benzene ring is 66.65 (3)°. The C atoms of themeta-methoxy groups lie close to the plane of the benzene ring [deviations = 0.052 (1) and −0.083 (1) Å], whereas the C atom of thepara-methoxy group is significantly displaced [deviation = −1.289 (1) Å]. In the crystal, carboxylic acid inversion dimers generateR22(8) loops. The dimers are connected by N—H...O hydrogen bonds, forming [011] chains. A C—H...O interaction is also observed.

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