Biological Activities of Natural Products

Euonymus laxiflorus Champ., a medicinal herb collected in Vietnam, has been reported to show several potent bioactivities, including anti-NO, enzyme inhibition, hypoglycemic and antidiabetic effects. Recently, the antioxidant activity of Euonymus laxiflorus Champ. trunk bark (ELCTB) has also been reported. However, the active antioxidant and anti-NO constituents existing in ELCTB have not been reported in the literature. The objective of this study was to purify the active antioxidants from ELCTB and investigate the anti-NO effect of the major constituents. Twenty-two phenolics isolated from ELCTB, including 12 compounds newly isolated in this study (1–12) and 10 constituents obtained from our previous work, were evaluated for their antioxidant activity. Of these, 12 compounds (4–6, 9, 13–15, 18–22) showed a potent antioxidant capacity (FRS50 = 7.8–58.11 µg/mL), in comparison to α-tocopherol (FRS50 = 23 µg/mL). In the anti-NO activity tests, Walterolactone A (1a) and B (1b) β-d-glucopyranoside (13) demonstrated the most effective and comparable activity to that of quercetin with max inhibition and IC50 values of 100%, 1.3 µg/mL, and 100%, 1.21 µg/mL, respectively. The crude extract and its major compounds showed no cytotoxicity on normal cells. Notably, three constituents (9, 11, and 12) were identified as new compounds, another three constituents, including 1, 7, and 8, were found to be new natural products, constituents 9 and 13 were determined to be new antioxidants, and compound 13 was reported to have novel potent anti-NO activity for the first time. The results of this study contribute to the enrichment of new natural products and compounds, as well as the novel biological activity of constituents isolated from Euonymus laxiflorus Champ. The current study also indicates ELCTB as a rich natural source of active phenolics. It is suggested that ELCTB could be developed as a health food with promising antioxidant and anti-NO effects, as well as other beneficial biological activities.

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Pyrone-derived Marine Natural Products: A Review on Isolation, Bio-activities and Synthesis

Current Organic Chemistry ◽

10.2174/1385272824666200217101400 ◽

2020 ◽

Vol 24 (4) ◽

pp. 354-401 ◽

Cited By ~ 2

Author(s):

Keisham S. Singh

Keyword(s):

Natural Products ◽

Marine Natural Products ◽

Marine Fungi ◽

Kojic Acid ◽

Biological Activities ◽

Biological Significance ◽

Pyrone Ring ◽

Enol Ethers ◽

Bioactive Natural Products ◽

Marine Metabolites

Marine natural products (MNPs) containing pyrone rings have been isolated from numerous marine organisms, and also produced by marine fungi and bacteria, particularly, actinomycetes. They constitute a versatile structure unit of bioactive natural products that exhibit various biological activities such as antibiotic, antifungal, cytotoxic, neurotoxic, phytotoxic and anti-tyrosinase. The two structure isomers of pyrone ring are γ- pyrone and α-pyrone. In terms of chemical motif, γ-pyrone is the vinologous form of α- pyrone which possesses a lactone ring. Actinomycete bacteria are responsible for the production of several α-pyrone compounds such as elijopyrones A-D, salinipyrones and violapyrones etc. to name a few. A class of pyrone metabolites, polypropionates which have fascinating carbon skeleton, is primarily produced by marine molluscs. Interestingly, some of the pyrone polytketides which are found in cone snails are actually synthesized by actinomycete bacteria. Several pyrone derivatives have been obtained from marine fungi such as Aspergillums flavus, Altenaria sp., etc. The γ-pyrone derivative namely, kojic acid obtained from Aspergillus fungus has high commercial demand and finds various applications. Kojic acid and its derivative displayed inhibition of tyrosinase activity and, it is also extensively used as a ligand in coordination chemistry. Owing to their commercial and biological significance, the synthesis of pyrone containing compounds has been given attention over the past years. Few reviews on the total synthesis of pyrone containing natural products namely, polypropionate metabolites have been reported. However, these reviews skipped other marine pyrone metabolites and also omitted discussion on isolation and detailed biological activities. This review presents a brief account of the isolation of marine metabolites containing a pyrone ring and their reported bio-activities. Further, the review covers the synthesis of marine pyrone metabolites such as cyercene-A, placidenes, onchitriol-I, onchitriol-II, crispatene, photodeoxytrichidione, (-) membrenone-C, lihualide-B, macrocyclic enol ethers and auripyrones-A & B.

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Natural products isolated from Casimiroa

Open Chemistry ◽

10.1515/chem-2020-0128 ◽

2020 ◽

Vol 18 (1) ◽

pp. 778-797

Author(s):

Khun Nay Win Tun ◽

Nanik Siti Aminah ◽

Alfinda Novi Kristanti ◽

Hnin Thanda Aung ◽

Yoshiaki Takaya

Keyword(s):

Natural Products ◽

Spectral Data ◽

Aromatic Compounds ◽

Biological Activities ◽

Chemical Constituents ◽

Quinoline Alkaloids

AbstractAbout 140 genera and more than 1,600 species belong to the Rutaceae family. They grow in temperate and tropical zones on both hemispheres, as trees, shrubs, and herbs. Casimiroa is one of the genera constituting 13 species, most of which are found in tropical and subtropical regions. Many chemical constituents have been derived from this genus, including quinoline alkaloids, flavonoids, coumarins, and N-benzoyltyramide derivatives. This article reviews different studies carried out on aromatic compounds of genus Casimiroa; their biological activities; the different skeletons of coumarins, alkaloids, flavonoids, and others; and their characteristic NMR spectral data.

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Natural Products from Tongan Marine Organisms

Molecules ◽

10.3390/molecules26154534 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4534

Author(s):

Taitusi Taufa ◽

Ramesh Subramani ◽

Peter Northcote ◽

Robert Keyzers

Keyword(s):

Natural Products ◽

Pacific Ocean ◽

Biological Activities ◽

Marine Sponges ◽

Marine Organisms ◽

Biologically Active ◽

Geographic Variability ◽

South Pacific Ocean ◽

New Novel ◽

Rich Diversity

The islands of the South Pacific Ocean have been in the limelight for natural product biodiscovery, due to their unique and pristine tropical waters and environment. The Kingdom of Tonga is an archipelago in the central Indo-Pacific Ocean, consisting of 176 islands, 36 of which are inhabited, flourishing with a rich diversity of flora and fauna. Many unique natural products with interesting bioactivities have been reported from Indo-Pacific marine sponges and other invertebrate phyla; however, there have not been any reviews published to date specifically regarding natural products from Tongan marine organisms. This review covers both known and new/novel Marine Natural Products (MNPs) and their biological activities reported from organisms collected within Tongan territorial waters up to December 2020, and includes 109 MNPs in total, the majority from the phylum Porifera. The significant biological activity of these metabolites was dominated by cytotoxicity and, by reviewing these natural products, it is apparent that the bulk of the new and interesting biologically active compounds were from organisms collected from one particular island, emphasizing the geographic variability in the chemistry between these organisms collected at different locations.

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Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Polymers ◽

10.3390/polym13091441 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1441

Author(s):

Yangpeng Lu ◽

Yanan Jia ◽

Zihan Xue ◽

Nannan Li ◽

Junyu Liu ◽

...

Keyword(s):

Biological Activities ◽

Structural Characteristics ◽

Potential Candidate ◽

Health Food ◽

Inonotus Obliquus ◽

Recent Developments ◽

Inonotus Obliquus Polysaccharide ◽

Future Work

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.

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

Molecules ◽

10.3390/molecules26020249 ◽

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.

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Biosynthesis and synthetic biology of psychoactive natural products

Chemical Society Reviews ◽

10.1039/d1cs00065a ◽

2021 ◽

Author(s):

Cooper S. Jamieson ◽

Joshua Misa ◽

Yi Tang ◽

John M. Billingsley

Keyword(s):

Natural Products ◽

Synthetic Biology ◽

Biological Activities ◽

Engineering Applications ◽

Pathway Discovery

The biosynthetic logic employed by Nature in the construction of psychoactive natural products is reviewed, in addition to biological activities, methodologies enabling pathway discovery, and engineering applications.

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Natural Products Targeting the Mitochondria in Cancers

Molecules ◽

10.3390/molecules26010092 ◽

2020 ◽

Vol 26 (1) ◽

pp. 92

Author(s):

Yue Yang ◽

Ping-Ya He ◽

Yi Zhang ◽

Ning Li

Keyword(s):

Natural Products ◽

Anticancer Drugs ◽

Web Of Science ◽

Keyword Search ◽

Biological Activities ◽

Natural Compounds ◽

New Drugs ◽

Antitumor Effects ◽

Regulate Cell Growth ◽

Anticancer Drug Discovery

There are abundant sources of anticancer drugs in nature that have a broad prospect in anticancer drug discovery. Natural compounds, with biological activities extracted from plants and marine and microbial metabolites, have significant antitumor effects, but their mechanisms are various. In addition to providing energy to cells, mitochondria are involved in processes, such as cell differentiation, cell signaling, and cell apoptosis, and they have the ability to regulate cell growth and cell cycle. Summing up recent data on how natural products regulate mitochondria is valuable for the development of anticancer drugs. This review focuses on natural products that have shown antitumor effects via regulating mitochondria. The search was done in PubMed, Web of Science, and Google Scholar databases, over a 5-year period, between 2015 and 2020, with a keyword search that focused on natural products, natural compounds, phytomedicine, Chinese medicine, antitumor, and mitochondria. Many natural products have been studied to have antitumor effects on different cells and can be further processed into useful drugs to treat cancer. In the process of searching for valuable new drugs, natural products such as terpenoids, flavonoids, saponins, alkaloids, coumarins, and quinones cover the broad space.

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Imidazole: Having Versatile Biological Activities

Journal of Chemistry ◽

10.1155/2013/329412 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 27

Author(s):

Amita Verma ◽

Sunil Joshi ◽

Deepika Singh

Keyword(s):

Natural Products ◽

Nucleic Acid ◽

Biological Activities ◽

Imidazole Ring ◽

Heterocyclic Ring ◽

Heterocyclic Chemistry ◽

The Past ◽

Poorly Soluble ◽

Anti Hiv ◽

Imidazole Compounds

Imidazoles have occupied a unique position in heterocyclic chemistry, and its derivatives have attracted considerable interests in recent years for their versatile properties in chemistry and pharmacology. Imidazole is nitrogen-containing heterocyclic ring which possesses biological and pharmaceutical importance. Thus, imidazole compounds have been an interesting source for researchers for more than a century. The imidazole ring is a constituent of several important natural products, including purine, histamine, histidine, and nucleic acid. Being a polar and ionisable aromatic compound, it improves pharmacokinetic characteristics of lead molecules and thus is used as a remedy to optimize solubility and bioavailability parameters of proposed poorly soluble lead molecules. There are several methods used for the synthesis of imidazole-containing compounds, and also their various structure reactions offer enormous scope in the field of medicinal chemistry. The imidazole derivatives possess extensive spectrum of biological activities such as antibacterial, anticancer, antitubercular, antifungal, analgesic, and anti-HIV activities. This paper aims to review the biological activities of imidazole during the past years.

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Chemical Diversity and Biological Activity of Secondary Metabolites Isolated from Indonesian Marine Invertebrates

Molecules ◽

10.3390/molecules26071898 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1898

Author(s):

Fauzia Izzati ◽

Mega Ferdina Warsito ◽

Asep Bayu ◽

Anggia Prasetyoputri ◽

Akhirta Atikana ◽

...

Keyword(s):

Natural Products ◽

Bioactive Compounds ◽

Marine Natural Products ◽

Biological Function ◽

Marine Invertebrates ◽

Biological Activities ◽

Structural Diversity ◽

Chemical Diversity ◽

Soft Corals ◽

High Chemical

Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007–2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates.

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