scholarly journals Bicyclo [6.3.0] Undecane Sesquiterpenoids: Structures, Biological Activities, and Syntheses

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3912 ◽  
Author(s):  
Guo-Fei Qin ◽  
Hong-Bao Liang ◽  
Wen-Xiu Liu ◽  
Feng Zhu ◽  
Ping-Lin Li ◽  
...  
Keyword(s):  
Natural Products ◽  
Biological Activities ◽  
Membered Ring ◽  
Isopropyl Group ◽  
Total Syntheses ◽  
The Core ◽  
Naturally Occurring ◽  
Important Target ◽  
Wide Range ◽  
Antiviral Activities

Sesquiterpenoids constitute a marvelously varied group of natural products that feature a vast array of molecular architectures. Among them, the unusual bicyclo [6.3.0] undecane sesquiterpenoids are one of the most representative. To date, only approximately 42 naturally occurring compounds with this unique scaffold, which can be classified into seven different groups, have been reported. As the first-found member of each type, dactylol, asteriscanolide, dumortenol, toxicodenane C, and capillosanane S are characteristic of the four methyl groups on the five-eight-membered ring system. Only 11-hydroxyjasionone and sinuketal decorate the core with an isopropyl group. These natural products exhibit a wide range of bioactivities, including antifouling, anti-inflammatory, immune suppression, cytotoxic, antimutagenic, antiplasmodial, and antiviral activities. It was noted that some total syntheses of precapnellane-sesquiterpenoids (dactylol, poitediol, precapnelladiene), asteriscanolide, and 11-hydroxyjasionone have been achieved, because their cyclooctanoid core represents an important target for the development of synthetic strategies to prepare eight-membered ring-containing compounds. This review focuses on these natural sesquiterpenoids and their biological activities and synthesis, and aims to provide a foundation for further research of these interesting compounds.

scholarly journals Oxazolidinones as Chiral Auxiliaries in the Asymmetric 1,4-Conjugate Addition Reaction Applied to the Total Synthesis of Natural Products: A Supplemental Mini-Review

2018 ◽  
Vol 15 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Vahideh Zadsirjan ◽  
Majid M. Heravi
Keyword(s):  
Total Synthesis ◽  
Biological Activities ◽  
Conjugate Addition ◽  
Chiral Auxiliary ◽  
Addition Reactions ◽  
Chiral Auxiliaries ◽  
Complex Molecules ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Wide Range

Background: The most frequently used chiral auxiliaries, oxazolidinones (Evans' oxazolidinones) have been employed in 1,4-congugate addition reactions to α,β-unsaturated carbonyl compounds. Supplementary to our previous reports in this mini-review, we attempted to underscore the applications of this strategy in a step (steps) in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Objective: In this mini-review, we try to underscore the applications of oxazolidinones (Evans’ oxazolidinones) in 1,4-congugate addition reactions to α,β-unsaturated carbonyl in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Conclusion: In spite of well-known superiority of asymmetric catalyzed reactions, the use of auxiliarycontrolled reactions are still considered as commanding, vital and sometimes as only tools in the generation of stereogenic centers during the construction of complex molecules and total synthesis of naturally occurring compounds. The commercial availability, or readily accessibility of a wide variety of chiral amino alcohols as starting materials to synthesize a wide range of oxazolidinones is the merits of them. In addition, the ease of removal and subjection to various and diverse stereoselective reactions make oxazolidinones as the ideal and superior chiral auxiliaries. In this regard, they were successfully used in asymmetric 1,4-conjugate addition reactions with high stereoselectivities. The high degree of asymmetric induction can be attributed to the rigid chelation of N-acyloxazolidinones with metal ions, as well as the covering of one face of the system by the bulkiness of 4-substituent. In summary, in this report, the importance of the applications of chiral oxazolidinones as suitable chiral auxiliaries in the stereoselective, 1,4-conjugate addition reactions in asymmetric synthesis and in particular, the total synthesis of naturally occurring compounds and some complex molecules were underscored. Noticeably, in these total syntheses, this chiral auxiliary is controlling the stereochemistry of a newly created stereogenic center as well as preserving the configuration of other chiral centers, which already have been presented in the precursor. General methods have been established for the attachment of the chiral auxiliary as a moiety to the substrate molecule in high to excellent yields. At the end of these reactions, this auxiliary can be easily removed leaving various desired reactive motifs for the next step in multi-step synthesis.

3,4-Dihydroisocoumarins, Interesting Natural Products: Isolation, Organic Syntheses and Biological Activities

2019 ◽  
Vol 16 (1) ◽  
pp. 112-129 ◽  
Author(s):  
Aurelio Ortiz ◽  
Miriam Castro ◽  
Estibaliz Sansinenea
Keyword(s):  
Natural Products ◽  
Biological Activities ◽  
Natural Compounds ◽  
Biologically Active ◽  
Bacterial Strains ◽  
Drug Candidates ◽  
Heterocyclic Molecules ◽  
Naturally Occurring ◽  
Wide Range ◽  
Different Sources

Background:3,4-dihydroisocoumarins are an important small group belonging to the class of naturally occurring lactones isolated from different bacterial strains, molds, lichens, and plants. The structures of these natural compounds show various types of substitution in their basic skeleton and this variability influences deeply their biological activities. These lactones are structural subunits of several natural products and serve as useful intermediates in the synthesis of different heterocyclic molecules, which exhibit a wide range of biological activities, such as anti-inflammatory, antiplasmodial, antifungal, antimicrobial, antiangiogenic and antitumoral activities, among others. Their syntheses have attracted attention of many researchers reporting many synthetic strategies to achieve 3,4-dihydroisocoumarins and other related structures. </P><P> Objective: In this context, the isolation of these natural compounds from different sources, their syntheses and biological activities are reviewed, adding the most recent advances and related developments.Conclusion:This review aims to encourage further work on the isolation and synthesis of this class of natural products. It would be beneficial for synthetic as well as the medicinal chemists to design selective, optimized dihydroisocoumarin derivatives as potential drug candidates, since dihydroisocoumarin scaffolds have significant utility in the development of therapeutically relevant and biologically active compounds.

Total synthesis of bryostatin 3

Science ◽  
2020 ◽  
Vol 368 (6494) ◽  
pp. 1007-1011 ◽  
Author(s):  
Barry M. Trost ◽  
Youliang Wang ◽  
Andreas K. Buckl ◽  
Zhongxing Huang ◽  
Minh H. Nguyen ◽  
...  
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Marine Natural Products ◽  
Biological Activities ◽  
Step Count ◽  
Total Syntheses ◽  
Linear Sequence ◽  
Wide Range

Bryostatins are a family of 21 complex marine natural products with a wide range of potent biological activities. Among all the 21 bryostatins, bryostatin 3 is structurally the most complex. Whereas nine total syntheses of bryostatins have been achieved to date, bryostatin 3 has only been targeted once and required the highest number of steps to synthesize (43 steps in the longest linear sequence and 88 total steps). Here, we report a concise total synthesis of bryostatin 3 using 22 steps in the longest linear sequence and 31 total steps through a highly convergent synthetic plan by the use of highly atom-economical and chemoselective transformations in which alkynes played a major role in reducing step count.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Development and characterization of electrospun curcumin-loaded antimicrobial nanofibrous membranes

2020 ◽  
pp. 004051752092551
Author(s):  
Javeed A Awan ◽  
Saif Ur Rehman ◽  
Muhammad Kashif Bangash ◽  
Fiaz Hussain ◽  
Jean-Noël Jaubert
Keyword(s):  
Biological Activities ◽  
Research Work ◽  
Medical Applications ◽  
Electrospinning Technique ◽  
Naturally Occurring ◽  
Wide Range ◽  
Nanofibrous Membranes ◽  
Antimicrobial Barrier ◽  
Anti Hiv

Curcumin is a naturally occurring hydrophobic polyphenol compound. It exhibits a wide range of biological activities such as antibacterial, anti-inflammatory, anti-carcinogenic, antifungal, anti-HIV, and antimicrobial activity. In this research work, antimicrobial curcumin nanofibrous membranes are produce by an electrospinning technique using the Eudragit RS 100 (C19H34ClNO6) polymer solution enriched with curcumin. The morphology and chemistry of the membrane are analyzed using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Kirby Bauer disk diffusion tests are carried out to examine the antibacterial effectiveness of the membrane. Experimental results show that the nanofibers produced are of uniform thickness morphology and curcumin is successfully incorporated into the nanofibrous mat, while no chemical bonding was observed between curcumin and the polymer. The antimicrobial curcumin nanofibrous membranes can be effectively applied as antimicrobial barrier in a wide variety of medical applications such as wound healing, scaffolds, and tissue engineering.

Combinatorial Synthesis of Novel 3/5(3,5)-(Di)nitro/chloropaeonol Carbonyl Hydrazone Derivatives as Nematicidal Agents

2021 ◽  
Vol 24 ◽  
Author(s):  
Genqiang Chen ◽  
Lina Zhu ◽  
Yanfei Xia ◽  
Jinming Yang ◽  
Song Zhang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Biological Activities ◽  
Science Research ◽  
Nematicidal Activity ◽  
Effective Control ◽  
Root Bark ◽  
Naturally Occurring ◽  
Whole Plant ◽  
Wide Range

Background: Developing the high-efficiency and low-risk small-molecule green-nematocide is the key of effective control of the nematodes. Paeonol, is a naturally occurring phenolic compound, isolated from the root bark of Paeonia suffruticosa and the whole plant of Cynanchum paniculatum. Due to its crucial phenolic ketone skeleton, modern biological science research has indicated that paeonol has a wide range of biological activities. The structural modification of paeonol into paeonol carbonyl hydrazone derivatives is a potential approach for the development of novel nematodes, which showed more toxicity than paeonol. However, there are no reports on the nematicidal activity of paeonol carbonyl hydrazone derivatives to control Heterodera glycines. Results: We always endeavor to discover and develop biorational natural products-based pesticidal agents, 4 significant intermediates and 21 novel 3/5(3,5)-(di)nitro/chloropaeonol carbonyl hydrazone derivatives were prepared, and their structures well characterized by 1H NMR, HRMS, MS, and mp. Due to the steric hindrance, the substituents on the C=N double bond of all hydrazine compounds adopted E configuration. Results of nematicidal activity revealed that, among all compounds, especially 5-nitropaeonol (5) and 3,5-dinitropaeonol (7) displayed the most potent nematicidal activity H. glycines in vivo with LC50 values of 0.0323 and 0.0367 mg/mL, respectively. Conclusion: It suggested that for the 3/5(3,5)-(di)nitro/chloropaeonol carbonyl hydrazone derivatives, a nitro group introduced at C5 position of 1 was necessary for obtaining the potent compound as nematicidal agents. These preliminary results will pave the way for further modification of paeonol in the development of potential new nematicides.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

scholarly journals ANTIOXIDANT POTENTIAL OF PIPERIDINE CONTAINING COMPOUNDS-A SHORT REVIEW

2018 ◽  
Vol 11 (8) ◽  
pp. 66
Author(s):  
Manjusha R K ◽  
Shaheen Begum ◽  
Arifa Begum ◽  
Bharathi K
Keyword(s):  
Biological Activities ◽  
Short Review ◽  
Heterocyclic Ring ◽  
Antioxidant Potential ◽  
Naturally Occurring ◽  
Antioxidant Profile ◽  
Antioxidant Agents ◽  
Wide Range ◽  
Privileged Scaffold ◽  
Candidate Molecule

Piperidine is a saturated heterocyclic ring, considered as a privileged scaffold in view of its role in wide range of biological activities. Piperidine is good candidate molecule for obtaining potent antioxidant agents. The planar nature of this heterocyclic nucleus allows the introduction of substituent groups at different positions on the ring. In the present review, the antioxidant profile of piperidine containing compounds has been focused. The compounds were classified into naturally occurring piperidines, unsaturated piperidines, N-substituted piperidines, piperamides, piperanols, piperidine oximes, and hydrazides.

Naturally occurring and synthetic polyyne glycosides

2009 ◽  
Vol 87 (11) ◽  
pp. 1565-1582 ◽  
Author(s):  
Yanqing Pan ◽  
Todd L. Lowary ◽  
Rik R. Tykwinski
Keyword(s):  
Natural Products ◽  
Marine Algae ◽  
Biological Activities ◽  
Terrestrial Plants ◽  
Natural Sources ◽  
Naturally Occurring

Polyyne glycosides are a class of natural products that have been found in terrestrial plants, fungi, and marine algae. Many display interesting and potentially useful biological activities, which in some cases has initiated synthetic efforts toward their formation. This review provides a comprehensive report of polyyne glycosides isolated from natural sources, as well as the synthesis of these molecules and their analogues.

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