scholarly journals One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

2020 ◽  
Vol 16 ◽  
pp. 1456-1464
Author(s):  
Aleksandar Pashev ◽  
Nikola Burdzhiev ◽  
Elena Stanoeva
Keyword(s):  
Succinic Anhydride ◽  
Building Blocks ◽  
2D Nmr ◽  
Bioactive Molecules ◽  
Exocyclic Double Bond ◽  
Nmr Techniques ◽  
One Step ◽  
Bridgehead Nitrogen ◽  
New Compounds ◽  
Isoquinoline Derivatives

The Castagnoli–Cushman reaction of 3,4-dihydroisoquinolines with glutaric anhydride, its oxygen and sulfur analogues was investigated as a one-step approach to the benzo[a]quinolizidine system and its heterocyclic analogs. An extension towards the pyrrolo[2,1-a]isoquinoline system was achieved with the use of succinic anhydride. The results are evidence of an unexplored method for the access of the aforementioned tricyclic annelated systems incorporating a bridgehead nitrogen atom. The structures and relative configurations of the new compounds were established by means of 1D and 2D NMR techniques. The reactions between 1-methyldihydroisoquinoline and glutaric, diglycolic and succinic anhydrides yielded unexpected isoquinoline derivatives containing an exocyclic double bond. The compounds prepared bear the potential to become building blocks for future synthetic bioactive molecules.

scholarly journals β-Elemene derivatives produced from SeO 2 -mediated oxidation reaction

2020 ◽  
Vol 7 (5) ◽  
pp. 200038
Author(s):  
Xingrui He ◽  
Xiao-Tao Zhuo ◽  
Yuan Gao ◽  
Renren Bai ◽  
Xiang-Yang Ye ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Oxidation Reaction ◽  
2D Nmr ◽  
Single Step ◽  
Easy Access ◽  
Nmr Techniques ◽  
One Step ◽  
New Compounds ◽  
Mediated Oxidation

Herein, we report the first access of β-elemene derivatives through the SeO 2 -mediated oxidation reaction. Several new compounds were isolated through such a one-step reaction, and their structures were elucidated using various 2D-NMR techniques. This method provides easy access to multiple oxidative β-elemene derivatives in one single step and represents the first modifications on cyclohexyl ring of β-elemene. It is expected to open up the opportunity for future derivatization on cyclohexyl ring of β-elemene. The new compounds obtained above showed better anti-proliferation activities than β-elemene itself on several cancer cell lines. Among them, compound 17 shows the best activity in antiproliferation assays of A549 and U-87MG cell lines.

scholarly journals Isolation and Characterization of Two New Antimicrobial Acids from Quercus incana (Bluejack Oak)

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Rizwana Sarwar ◽  
Umar Farooq ◽  
Sadia Naz ◽  
Nadia Riaz ◽  
Syed Majid Bukhari ◽  
...  
Keyword(s):  
Ethyl Acetate Fraction ◽  
Structural Formula ◽  
2D Nmr ◽  
Spectroscopic Technique ◽  
Pentanoic Acid ◽  
One Dimensional ◽  
Isolation And Characterization ◽  
Nmr Techniques ◽  
New Compounds

Two new compounds [1-2] were purified from ethyl acetate fraction of Quercus incana. The structure of these compounds is mainly established by using advanced spectroscopic technique such as UV, IR, one-dimensional (ID) and two-dimensional (2D) NMR techniques, and EI mass. The structural formula was deduced to be 4-hydroxydecanoic acid [1] and 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2]. Both isolated compounds were tested for their antimicrobial potential and showed promising antifungal activity against Aspergillus niger and Aspergillus flavus.

scholarly journals Diterpenoid alkaloids from Aconitum and Delphinum species

2018 ◽  
pp. 3-9
Author(s):  
Batsuren D ◽  
Batbayar N ◽  
Tunsag J
Keyword(s):  
Plant Species ◽  
High Resolution Mass Spectrometry ◽  
2D Nmr ◽  
Crystallographic Analysis ◽  
Hydroxyl Groups ◽  
Diterpenoid Alkaloids ◽  
Alkaloid Composition ◽  
Nmr Techniques ◽  
New Compounds ◽  
Oxygen Atoms

Since 1986 we started investigating diterpene alkaloids from Aconitum and Delphinum species in Mongolia. Alkaloid composition of some 12 species of Aconitum and Delphinum of Ranunculaceae family and 63 individual compounds were isolated and identified. Among them 9 were newly found naturally-occurring compounds and structure of these alkaloids were elucidated completely. High resolution Mass-spectrometry, 1H and 13C NMR, 2D NMR techniques such as COSY, HMQC, HMBC were employed to elucidate structure of new compounds. Structure of altaconitine was elucidated and confirmed by applying X-ray crystallographic analysis in addition to above- mentioned techniques. As a result of our long-term chemical in-vestigation of plant species of Mongolia, we have observed and established that secondary metabolites such as alkaloids, coumarins, lignans and xanthones accumulate in more oxidized form in plant species grown in Mongolia. This principle is also demonstrated in the structure of diterpenoid alkaloids isolated from plants of Ranunculaceae family grown in Mongolia. As can be seen from alkaloids 11-acetyl-1, 19-epoxydenudatine and turpelline each contain 4 oxygen atoms, which is more oxygen atoms than in commonly-occurring C-20 diterpenoid alkaloids. Except turpelline no other C-20 alkaloid containing four hydroxyl groups was found in nature. Altaconitine is a newly discovered alkaloid which contains functional groups with highest number of oxygen atoms among C-19 diterpenoid alkaloids. Ring “A” in altaconitine structure is substituted at C-1, C-2 and C-3 positions with 2, 3-transdiol system, making altaconitine a unique structure found in nature. Хорс ба Гэзэг цэцгийн төрлийн ургамлын дитерпений алкалоид Хураангуй: Дэлхий дахинаа Aconitum, Astagne, Consolida, Delphinum ба Inula-гийн төрлийн ургамлууд нь дитерпений алкалоидын баялаг эх сурвалж бөгөөд манай оронд тэдгээрээс Хорс ба Гэзэг цэцэгийн төрлийн ургамлууд элбэг тохиолддог. Холтсон цэцгийн овгийн Хорс ба Гэзэг цэцэгийн төрөлд хамаарагдах 12 зүйл ургамалд дитерпений алкалоидын судалгаа явуулж, дээрхи ургамлуудаас С-19, С-20 дитерпений алкалоидод хамаарагдах 63 бодисыг химийн цэвэр байдлаар ялгаж, тэдгээрийн бүтцийг таньж тодорхойлсоны дотор 9 дитерпений шинэ алкалоидыг анх удаа байгалиас олсон. Эдгээрийн дотроос бүтцийн хувьд нилээд сонирхолтой нь альтаконитин бөгөөд тэр нь 6 хираль нүүрстөрөгчийн атом агуулсан цууны ба бензоины хүчлээр ацилжсан, үндсэн цагиргийн 10 нүүрстөрөгчийн атом нь хүчилтөрөгч бүхий халагч бүлэгтэй ба ялангуяа “А” цагиргийн 2 ба 3-р байрлалд буй гидроксил бүлгүүд нь транс диол систем бүхий рекорд исэлдсэн хэлбэртэй, өвөрмөц бүтэц бүхий байгалийн шинэ алкалоид юм. Түүнчлэн турпеллин алкалоид нь үндсэн цагиргийн 4 нүүрстөрөгчийн атом нь хүчилтөрөгч бүхий халагч бүлэгтэй байгаа нь тус алкалоид бүтцийн хувьд рекорд исэлдсэн напеллины төрлийн цорын ганц нэгдэл болж бүртгэгдээд байна. Түлхүүр үгс: Хорс, Гэзэг цэцэг, дитерпений алкалоид

scholarly journals Two New Eremophilane Sesquiterpenes and One New Resorcinol from Ligularia Knorringiana

2016 ◽  
Vol 11 (2) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Wei Dai ◽  
Hui Li ◽  
Wenli Cong ◽  
Wenbin Zhao ◽  
Qi Wang
Keyword(s):  
2D Nmr ◽  
Spectroscopic Methods ◽  
Nmr Techniques ◽  
New Compounds

Two new eremophilane sesquiterpenes, 12-oxa-1β, 5β,8,9aβ-tetramethyl-4α,5-ethano-4aβ-hydroxy-7β,10aβ-epoxy-9β-angeloyloxy-1,2,3,4,4a,5,6,7,9,9a,10,10a-dodecahydro-anthracen-13-on (knorringianalarin A, 1) and 6,9-dien-8-oxoeremophil-12-nor-11-ketone (knorringianalarin B, 2), and a new resorcinol, 4-acetyl-6-(2-methylpropionyl)-1,3-resorcinol (knorringianalarin C, 3) were isolated from the roots and rhizomes of Ligularia knorringiana, together with three known eremophilane sesquiterpenes (4–6). The structures of the new compounds were identified by spectroscopic methods including 2D-NMR techniques.

scholarly journals Accramycin A, a New Aromatic Polyketide, from the Soil Bacterium, Streptomyces sp. MA37

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3384 ◽  
Author(s):  
Maglangit ◽  
Fang ◽  
Leman ◽  
Soldatou ◽  
Ebel ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Group B Streptococcus ◽  
Antibacterial Properties ◽  
Building Blocks ◽  
2D Nmr ◽  
Soil Bacterium ◽  
Bioactive Molecules ◽  
Streptomyces Sp ◽  
Aromatic Polyketides ◽  
Group B

Drug-like molecules are known to contain many different building blocks with great potential as pharmacophores for drug discovery. The continued search for unique scaffolds in our laboratory led to the isolation of a novel Ghanaian soil bacterium, Streptomyces sp. MA37. This strain produces many bioactive molecules, most of which belong to carbazoles, pyrrolizidines, and fluorinated metabolites. Further probing of the metabolites of MA37 has led to the discovery of a new naphthacene-type aromatic natural product, which we have named accramycin A 1. This molecule was isolated using an HPLC-photodiode array (PDA) guided isolation process and MS/MS molecular networking. The structure of 1 was characterized by detailed analysis of LC-MS, UV, 1D, and 2D NMR data. Preliminary studies on the antibacterial properties of 1 using Group B Streptococcus (GBS) produced a minimum inhibitory concentration (MIC) of 27 µg/mL. This represents the first report of such bioactivity amongst the naphthacene-type aromatic polyketides, and also suggests the possibility for the further development of potent molecules against GBS based on the accramycin scaffold. A putative acc biosynthetic pathway for accramycin, featuring a tridecaketide-specific type II polyketide synthase, was proposed.

scholarly journals Two New Compounds from Paeonia lactiflora

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000
Author(s):  
QingHu Wang ◽  
Nayintai Dai ◽  
Narenchaoketu Han ◽  
Wuliji Ao
Keyword(s):  
Ethanol Extract ◽  
2D Nmr ◽  
Diethyl Ester ◽  
Spectroscopic Methods ◽  
Paeonia Lactiflora ◽  
Esi Ms ◽  
Nmr Techniques ◽  
New Compounds

Two new compounds, namely 5-methyl-4,2′,3′,5′-tetrahydroxy-4′-methoxy-2-aldehyde biphenyl (1) and 1,8-dioxo-1,8-dihydropyrano[3,4-c]pyran-3,6-dicarboxyl acid, diethyl ester (2), were isolated from the 95% ethanol extract of the roots of Paeonia lactiflora Pall. The structures of 1 and 2 were elucidated by spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.

Orthoamides and Iminium Salts, LXXX [1]. C-Glycosyl Alkynecarboxylic Acid Orthoamides. Versatile Intermediates in the Synthesis of New Types of Highly Substituted C-Nucleoside Analogs

2012 ◽  
Vol 67 (7) ◽  
pp. 699-716 ◽  
Author(s):  
Konstantin Drandarov ◽  
Willi Kantlehner
Keyword(s):  
Model Compound ◽  
Nucleoside Analogs ◽  
Building Blocks ◽  
2D Nmr ◽  
General Character ◽  
Terminal Alkynes ◽  
Iminium Salts ◽  
Synthetic Strategy ◽  
Nmr Techniques ◽  
Sugar Derivatives

The C-glycosyl alkynecarboxylic acid orthoamides 22 and 23 are proposed as versatile precursors for the synthesis of new types of C-nucleoside analogs. The new synthetic strategy includes alkynylation of protected aldoses 13 or ketoses by Grignard ethynylation or Barbier propargylation, O-protection of the resulting alkynols 14-16, and nucleophilic addition of the metalated protected terminal alkynes 20 and 21 to peralkylguanidinium salt 2 to afford the corresponding alkynecarboxylic acid orthoamides 22 and 23, which in reactions with mono or bis-nucleophiles could serve as building blocks for the construction of a wide variety of C-nucleoside-like binary conjugates. All the steps are demonstrated on 2,4,3,5-bis(4-methoxybenzylidene)-protected L-xylose 11 as a model compound. The synthesis of a representative series of C-glycosidic conjugates of highly substituted “push-pull” 1,3-butadienes 32-35, pyrimidines 24-31, and 2-pyridones 36-39 is included. The stereochemistry of all described compounds is established by 2D-NMR techniques. A general character of the proposed synthetic strategy, when applied to different appropriately protected sugar derivatives, is suggested, and a biomedical applicability of the described type of conjugates is expected.

Biotransformation of caffeic acid by Momordica charantia peroxidase

2008 ◽  
Vol 86 (8) ◽  
pp. 821-830 ◽  
Author(s):  
Xiang Wan ◽  
Haili Liu ◽  
Xuefeng Huang ◽  
Jianguang Luo ◽  
Lingyi Kong
Keyword(s):  
Antioxidant Activity ◽  
Caffeic Acid ◽  
2D Nmr ◽  
Momordica Charantia ◽  
The Other ◽  
Oxidative Activity ◽  
Nmr Techniques ◽  
New Compounds ◽  
First Time

Biotransformation of caffeic acid with H2O2/Momordica charantia peroxidase at pH 5.0, 25 °C in the presence of acetone has resulted in the isolation of three caffeic acid trimers 1–3, five caffeic acid dimers 4–8, and one monomer 9. Among them, seven (1–7) are new compounds, and two (8 and 9) are known compounds, including one compound (9), which was obtained by biotransformation for the first time. The structures were established by 2D NMR techniques, such as HSQC, HMBC, and NOESY measurements. The possible mechanism for the formation of the products is also discussed. This is the first time that caffeic acid trimers have been obtained through the biotransformation of catalyzed by peroxidase in vitro. Compound 5 has shown much stronger anti-oxidative activity than the other caffeic acid polymers obtained.Key words: Momordica charantia peroxidase, caffeic acid, polymers of caffeic acid, biotransformation, antioxidant activity.

scholarly journals Synthesis of New Fused Benzothiadiazepines and Macrocyclic Sulfamides Starting from N,N-Disubstituted Sulfamides and N(Boc)-Sulfamides

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Mohamed Dehamchia ◽  
Zine Regainia
Keyword(s):  
Mass Spectrometry ◽  
Wide Spectrum ◽  
Building Blocks ◽  
Pharmacological Activities ◽  
Chemical Structures ◽  
New Chemical Entities ◽  
One Step ◽  
New Compounds

Herein, we describe an efficient one-step synthesis of new fused benzothiadiazepine-1,1-dioxides and macrocyclic sulfamides. The synthesis of these compounds was achieved in moderate yields starting from previously described N,N′-disubstituted symmetric sulfamides and N-tert-butoxycarbonyl, N′-alkyl sulfamide. The chemical structures of all the new compounds reported in this work were confirmed by NMR, IR, and mass spectrometry. These compounds are beneficial building blocks that can be used in deriving new chemical entities that exert a wide spectrum of pharmacological activities.

Sign in / Sign up

Export Citation Format

Share Document