E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Natural Products and Drug Discovery"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Natural Products Chemistry".

Deadline for manuscript submissions: 15 June 2019

Special Issue Editor

Guest Editor
Prof. Dr. Pinarosa Avato

Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro Via Orabona 4, 70125 Bari, Italy
Website | E-Mail
Phone: +390805442785
Fax: +390805442230
Interests: phytochemicals; natural products; plant biodiversity; medicinal plants; food plants; bioactivity; polyphenols; glucosinolates; biocides

Special Issue Information

Dear Colleagues,

Natural products hold a prominent position in the discovery and development of many drugs used nowadays, with diverse indications for human and animal health. Especially, plants have played a leading role as a source of specialized metabolites with medical effects; other organisms such as marine and terrestrial animals and microorganisms produce very important drug candidate molecules. Specialized metabolites from all these natural sources can be used directly as bioactive compounds, or as drug precursors. Due to their wide chemical diversity they can act as drug prototypes and/or be used as pharmacological tools for different targets. Some examples of natural metabolites which have been developed into useful medical drugs are the cardiotonic digoxin from Digitalis sp., the antimalarial artemisinin from Artemisia annua, the anti-cancer taxol, from Taxus sp., or the podophyllotoxin from Podophyllum peltatum, which served as synthetic model for the anti-cancer etoposide. The study of natural products is still attracting a great scientific attention and their current importance as valuable leads for drug discovery is undebatable. I cordially invite authors to contribute original articles, as well as survey articles, that will give the readers of Molecules updated and new perspective about natural products in drug discovery including, but not limited to natural sources, identification and separation of bioactive phytochemicals, standardization, new biological targets, pre-clinical and clinical trials, pharmacological effects/side effects, and bioassays.

Prof. Dr. Pinarosa Avato
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • natural products
  • drug discovery
  • phytochemicals
  • biocidal compounds
  • human and animal health
  • natural sources

Published Papers (12 papers)

View options order results:
result details:
Displaying articles 1-12
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
Spectroscopic Characterization and Cytotoxicity Assessment towards Human Colon Cancer Cell Lines of Acylated Cycloartane Glycosides from Astragalus boeticus L.
Molecules 2019, 24(9), 1725; https://doi.org/10.3390/molecules24091725
Received: 10 April 2019 / Revised: 29 April 2019 / Accepted: 1 May 2019 / Published: 3 May 2019
PDF Full-text (1361 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In several European countries, especially in Sweden, the seeds of the species Astragalus boeticus L. were widely used as coffee substitutes during the 19th century. Nonetheless, data regarding the phytochemistry and the pharmacological properties of this species are currently extremely limited. Conversely, other [...] Read more.
In several European countries, especially in Sweden, the seeds of the species Astragalus boeticus L. were widely used as coffee substitutes during the 19th century. Nonetheless, data regarding the phytochemistry and the pharmacological properties of this species are currently extremely limited. Conversely, other species belonging to the Astragalus genus have already been extensively investigated, as they were used for millennia for treating various diseases, including cancer. The current work was addressed to characterize cycloartane glycosides from A. boeticus, and to evaluate their cytotoxicity towards human colorectal cancer (CRC) cell lines. The isolation of the metabolites was performed by using different chromatographic techniques, while their chemical structures were elucidated by nuclear magnetic resonance (NMR) (1D and 2D techniques) and electrospray-ionization quadrupole time-of-flight (ESI-QTOF) mass spectrometry. The cytotoxic assessment was performed in vitro by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in Caco-2, HT-29 and HCT-116 CRC cells. As a result, the targeted phytochemical study of A. boeticus enabled the isolation of three new cycloartane glycosides, 6-O-acetyl-3-O-(4-O-malonyl)-β-d-xylopyranosylcycloastragenol (1), 3-O-(4-O-malonyl)-β-d-xylopyranosylcycloastragenol (2), 6-O-acetyl-25-O-β-d-glucopyranosyl-3-O-β-d-xylopyranosylcycloastragenol (3) along with two known compounds, 6-O-acetyl-3-O-β-d-xylopyranosylcycloastragenol (4) and 3-O-β-d-xylopyranosylcycloastragenol (5). Importantly, this work demonstrated that the acetylated cycloartane glycosides 1 and 4 might preferentially inhibit cell growth in the CRC cell model resistant to epidermal growth factor receptor (EGFR) inhibitors. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessArticle
Phenolic Compounds from Humulus lupulus as Natural Antimicrobial Products: New Weapons in the Fight against Methicillin Resistant Staphylococcus aureus, Leishmania mexicana and Trypanosoma brucei Strains
Molecules 2019, 24(6), 1024; https://doi.org/10.3390/molecules24061024
Received: 28 January 2019 / Revised: 9 March 2019 / Accepted: 10 March 2019 / Published: 14 March 2019
PDF Full-text (2449 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant Staphylococcus aureus (MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections [...] Read more.
New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant Staphylococcus aureus (MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections caused by Trypanosoma brucei and Leishmania mexicana are also of global concern, because of the mortality due to the low number of safe and effective treatments. Female inflorescences of hop produce specialized metabolites known for their antimicrobial effects but underexploited to fight against drug-resistant microorganisms. In this study, we assessed the antimicrobial potential of phenolic compounds against MRSA clinical isolates, T. brucei and L. mexicana. By fractionation process, we purified the major prenylated chalcones and acylphloroglucinols, which were quantified by UHPLC-UV in different plant parts, showing their higher content in the active flowers extract. Their potent antibacterial action (MIC < 1 µg/mL for the most active compound) was demonstrated against MRSA strains, through kill curves, post-antibiotic effects, anti-biofilm assays and synergy studies with antibiotics. An antiparasitic activity was also shown for some purified compounds, particularly on T. brucei (IC50 < 1 to 11 µg/mL). Their cytotoxic activity was assessed both on cancer and non-cancer human cell lines. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Figure 1

Open AccessArticle
Identification of Phytoconstituents in Leea indica (Burm. F.) Merr. Leaves by High Performance Liquid Chromatography Micro Time-of-Flight Mass Spectrometry
Molecules 2019, 24(4), 714; https://doi.org/10.3390/molecules24040714
Received: 24 January 2019 / Revised: 12 February 2019 / Accepted: 15 February 2019 / Published: 16 February 2019
Cited by 1 | PDF Full-text (1677 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Leea indica (Vitaceae) is a Southeast Asian medicinal plant. In this study, an ethyl acetate fraction of L. indica leaves was studied for its phytoconstituents using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-microTOF-Q-MS/MS) analysis. A total of 31 compounds of different classes, including benzoic [...] Read more.
Leea indica (Vitaceae) is a Southeast Asian medicinal plant. In this study, an ethyl acetate fraction of L. indica leaves was studied for its phytoconstituents using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-microTOF-Q-MS/MS) analysis. A total of 31 compounds of different classes, including benzoic acid derivatives, phenolics, flavonoids, catechins, dihydrochalcones, coumarins, megastigmanes, and oxylipins were identified using LC-MS/MS. Among them, six compounds including gallic acid, methyl gallate, (−)-epigallocatechin-3-O-gallate, myricetin-3-O-rhamnoside, quercetin-3-O-rhamnoside, and 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-β-d-glucopyranoside were isolated and identified by NMR analysis. The LC-MS/MS analysis led to the tentative identification of three novel dihydrochalcones namely 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-rutinoside, 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-glucosylpentoside and 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-(3″-O-galloyl)-β-d-glucopyranoside. The structural identification of novel dihydrochalcones was based on the basic skeleton of the isolated dihydrochalcone, 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-β-d-glucopyranoside and characteristic LC-MS/MS fragmentation patterns. This is the first comprehensive analysis for the identification of compounds from L. indica using LC-MS. A total 24 compounds including three new dihydrochalcones were identified for the first time from the genus Leea. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessFeature PaperArticle
Phenolic Content and Antioxidant Activity in Trifolium Germplasm from Different Environments
Molecules 2019, 24(2), 298; https://doi.org/10.3390/molecules24020298
Received: 19 December 2018 / Revised: 9 January 2019 / Accepted: 14 January 2019 / Published: 15 January 2019
PDF Full-text (1365 KB) | HTML Full-text | XML Full-text
Abstract
Phenolics are important mediators in plant-environment interactions. The presence and concentration of phenolic compounds and their antioxidant activity were evaluated in leaves and flowers of a set of Trifolium species originating from contrasting environments encompassing lowland and mountain sites. The current germplasm proved [...] Read more.
Phenolics are important mediators in plant-environment interactions. The presence and concentration of phenolic compounds and their antioxidant activity were evaluated in leaves and flowers of a set of Trifolium species originating from contrasting environments encompassing lowland and mountain sites. The current germplasm proved a great reservoir of phenolic compounds, with different chemical structure and, possibly, diversified biological activity. Germplasm groups with specific phenolic composition were observed. In some cases, different patterns bore a taxonomic meaning. Lowland germplasm showed higher concentration of total phenolics in leaves than mountain accessions (50.30 vs. 34.19 mg/g dry matter (DM)), while the latter had higher concentration in flowers (114.16 vs. 57.44 mg/g DM). Outstanding concentration of isoflavones was observed in leaves of lowland germplasm (24.19 mg/g DM), and of both proanthocyanidins and flavonoids in flowers of mountain germplasm (53.81 and 56.62 mg/g DM, respectively). The pattern of phenolic composition in lowland and mountain germplasm was suggestive of different adaptive strategies. Three assays of antioxidant activity were tested, which were characterised by rather different reactivity towards phenolic composition. The scavenging activity was higher for leaf extracts of lowland germplasm, and for flower extracts of mountain germplasm. Besides identifying germplasm of interest, this study also suggested possible links between environmental factors and concentration and composition of phenolic compounds. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessArticle
Studies on the Design and Synthesis of Marine Peptide Analogues and Their Ability to Promote Proliferation in HUVECs and Zebrafish
Received: 30 November 2018 / Revised: 17 December 2018 / Accepted: 17 December 2018 / Published: 25 December 2018
PDF Full-text (6787 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In our previous studies, tripeptide 1 was found to induce angiogenesis in zebrafish embryos and in HUVECs. Based on the lead compound 1, seven new marine tripeptide analogues 28 have been designed and synthesized in this paper to evaluate the [...] Read more.
In our previous studies, tripeptide 1 was found to induce angiogenesis in zebrafish embryos and in HUVECs. Based on the lead compound 1, seven new marine tripeptide analogues 28 have been designed and synthesized in this paper to evaluate the effects on promoting cellular proliferation in human endothelial cells (HUVECs) and zebrafish. Among them, compounds 57 possessed more remarkable increasing proliferation effects than other compounds, and the EC50 values of these and the leading compound 1 were 1.0 ± 0.002 μM, 1.0 ± 0.0005 μM, 0.88 ± 0.0972 μM, and 1.31 ± 0.0926 μM, respectively. Furthermore, 57 could enhance migrations (58.5%, 80.66% and 60.71% increment after culturing 48 h, respectively) and invasions (49.08%, 47.24% and 56.24% increase, respectively) in HUVECs compared with the vehicle control. The results revealed that the tripeptide including l-Tyrosine or d-Proline fragments instead of l-Alanine of leading compound 1 would contribute to HUVECs’ proliferation. Taking the place of the original (l-Lys-l-Ala) segment of leading compound 1, a new fragment (l-Arg-d-Val) expressed higher performance in bioactivity in HUVECs. In addition, compound 7 could promote angiogenesis in zebrafish assay and it was more interesting that it also could repair damaged blood vessels in PTK787-induced zebrafish at a low concentration. The above data indicate that these peptides have potential implications for further evaluation in cytothesis studies. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Figure 1

Open AccessArticle
Ethanolic Extract of Folium Sennae Mediates the Glucose Uptake of L6 Cells by GLUT4 and Ca2+
Molecules 2018, 23(11), 2934; https://doi.org/10.3390/molecules23112934
Received: 29 September 2018 / Revised: 2 November 2018 / Accepted: 8 November 2018 / Published: 9 November 2018
PDF Full-text (4706 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In today’s world, diabetes mellitus (DM) is on the rise, especially type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. T2DM has high morbidity, and therapies with natural products have attracted much attention in the recent past. In this paper, we [...] Read more.
In today’s world, diabetes mellitus (DM) is on the rise, especially type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. T2DM has high morbidity, and therapies with natural products have attracted much attention in the recent past. In this paper, we aimed to study the hypoglycemic effect and the mechanism of an ethanolic extract of Folium Sennae (FSE) on L6 cells. The glucose uptake of L6 cells was investigated using a glucose assay kit. We studied glucose transporter 4 (GLUT4) expression and AMP-activated protein kinase (AMPK), protein kinase B (PKB/Akt), and protein kinase C (PKC) phosphorylation levels using western blot analysis. GLUT4 trafficking and intracellular Ca2+ levels were monitored by laser confocal microscopy in L6 cells stably expressing IRAP-mOrange. GLUT4 fusion with plasma membrane (PM) was observed by myc-GLUT4-mOrange. FSE stimulated glucose uptake; GLUT4 expression and translocation; PM fusion; intracellular Ca2+ elevation; and the phosphorylation of AMPK, Akt, and PKC in L6 cells. GLUT4 translocation was weakened by the AMPK inhibitor compound C, PI3K inhibitor Wortmannin, PKC inhibitor Gö6983, G protein inhibitor PTX/Gallein, and PLC inhibitor U73122. Similarly, in addition to PTX/Gallein and U73122, the IP3R inhibitor 2-APB and a 0 mM Ca2+-EGTA solution partially inhibited the elevation of intracellular Ca2+ levels. BAPTA-AM had a significant inhibitory effect on FSE-mediated GLUT4 activities. In summary, FSE regulates GLUT4 expression and translocation by activating the AMPK, PI3K/Akt, and G protein–PLC–PKC pathways. FSE causes increasing Ca2+ concentration to complete the fusion of GLUT4 vesicles with PM, allowing glucose uptake. Therefore, FSE may be a potential drug for improving T2DM. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessArticle
Phytochemical and Analytical Characterization of Novel Sulfated Coumarins in the Marine Green Macroalga Dasycladus vermicularis (Scopoli) Krasser
Molecules 2018, 23(11), 2735; https://doi.org/10.3390/molecules23112735
Received: 11 September 2018 / Revised: 17 October 2018 / Accepted: 17 October 2018 / Published: 23 October 2018
PDF Full-text (2439 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The siphonous green algae form a morphologically diverse group of marine macroalgae which include two sister orders (Bryopsidales and Dasycladales) which share a unique feature among other green algae as they are able to form large, differentiated thalli comprising of a single, giant [...] Read more.
The siphonous green algae form a morphologically diverse group of marine macroalgae which include two sister orders (Bryopsidales and Dasycladales) which share a unique feature among other green algae as they are able to form large, differentiated thalli comprising of a single, giant tubular cell. Upon cell damage a cascade of protective mechanisms have evolved including the extrusion of sulfated metabolites which are involved in the formation of a rapid wound plug. In this study, we investigated the composition of sulfated metabolites in Dasycladus vermicularis (Dasycladales) which resulted in the isolation of two phenolic acids and four coumarins including two novel structures elucidated by nuclear magnetic resonance spectroscopy (NMR) as 5,8′-di-(6(6′),7(7′)-tetrahydroxy-3-sulfoxy-3′-sulfoxycoumarin), a novel coumarin called dasycladin A and 7-hydroxycoumarin-3,6-disulfate, which was named dasycladin B. In addition, an analytical assay for the chromatographic quantification of those compounds was developed and performed on a reversed phase C-18 column. Method validation confirmed that the new assay shows good linearity (R2 ≥ 0.9986), precision (intra-day R.S.D ≤ 3.71%, inter-day R.S.D ≤ 7.49%), and accuracy (recovery rates ranged from 104.06 to 97.45%). The analysis of several samples of Dasycladus vermicularis from different collection sites, water depths and seasons revealed differences in the coumarin contents, ranging between 0.26 to 1.61%. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessArticle
Antinociceptive Effects of Cardamonin in Mice: Possible Involvement of TRPV1, Glutamate, and Opioid Receptors
Molecules 2018, 23(9), 2237; https://doi.org/10.3390/molecules23092237
Received: 3 July 2018 / Revised: 29 July 2018 / Accepted: 30 July 2018 / Published: 3 September 2018
PDF Full-text (1685 KB) | HTML Full-text | XML Full-text
Abstract
Pain is one of the most common cause for hospital visits. It plays an important role in inflammation and serves as a warning sign to avoid further injury. Analgesics are used to manage pain and provide comfort to patients. However, prolonged usage of [...] Read more.
Pain is one of the most common cause for hospital visits. It plays an important role in inflammation and serves as a warning sign to avoid further injury. Analgesics are used to manage pain and provide comfort to patients. However, prolonged usage of pain treatments like opioids and NSAIDs are accompanied with undesirable side effects. Therefore, research to identify novel compounds that produce analgesia with lesser side effects are necessary. The present study investigated the antinociceptive potentials of a natural compound, cardamonin, isolated from Boesenbergia rotunda (L) Mansf. using chemical and thermal models of nociception. Our findings showed that intraperitoneal and oral administration of cardamonin (0.3, 1, 3, and 10 mg/kg) produced significant and dose-dependent inhibition of pain in abdominal writhing responses induced by acetic acid. The present study also demonstrated that cardamonin produced significant analgesia in formalin-, capsaicin-, and glutamate-induced paw licking tests. In the thermal-induced nociception model, cardamonin exhibited significant increase in response latency time of animals subjected to hot-plate thermal stimuli. The rota-rod assessment confirmed that the antinociceptive activities elicited by cardamonin was not related to muscle relaxant or sedative effects of the compound. In conclusion, the present findings showed that cardamonin exerted significant peripheral and central antinociception through chemical- and thermal-induced nociception in mice through the involvement of TRPV1, glutamate, and opioid receptors. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Figure 1

Open AccessArticle
Identification and Growth Inhibitory Activity of the Chemical Constituents from Imperata Cylindrica Aerial Part Ethyl Acetate Extract
Molecules 2018, 23(7), 1807; https://doi.org/10.3390/molecules23071807
Received: 27 June 2018 / Revised: 16 July 2018 / Accepted: 16 July 2018 / Published: 21 July 2018
PDF Full-text (2647 KB) | HTML Full-text | XML Full-text
Abstract
Imperata cylindrica (L.) Raeusch. (IMP) aerial part ethyl acetate extract has anti-proliferative, pro-apoptotic, and pro-oxidative effects towards colorectal cancer in vitro. The chemical constituents of IMP aerial part ethyl acetate extract were isolated using high-performance liquid chromatography (HPLC) and identified with tandem mass [...] Read more.
Imperata cylindrica (L.) Raeusch. (IMP) aerial part ethyl acetate extract has anti-proliferative, pro-apoptotic, and pro-oxidative effects towards colorectal cancer in vitro. The chemical constituents of IMP aerial part ethyl acetate extract were isolated using high-performance liquid chromatography (HPLC) and identified with tandem mass spectrometry (ESI-MS/MS) in combination with ultraviolet-visible spectrophotometry and 400 MHz NMR. The growth inhibitory effects of each identified component on BT-549 (breast) and HT-29 (colon) cancer cell lines were evaluated after 48/72 h treatment by MTT assay. Four isolated compounds were identified as trans-p-Coumaric acid (1); 2-Methoxyestrone (2); 11, 16-Dihydroxypregn-4-ene-3, 20-dione (3); and Tricin (4). Compounds (2), (3), and (4) exhibited considerable growth inhibitory activities against BT-549 and HT-29 cancer cell lines. Compounds (2), (3), and (4) are potential candidates for novel anti-cancer agents against breast and colorectal cancers. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Open AccessArticle
Cytotoxicity-Guided Isolation of Two New Phenolic Derivatives from Dryopteris fragrans (L.) Schott
Molecules 2018, 23(7), 1652; https://doi.org/10.3390/molecules23071652
Received: 29 May 2018 / Revised: 21 June 2018 / Accepted: 1 July 2018 / Published: 6 July 2018
PDF Full-text (2065 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Dryopteris fragrans is a valuable medicinal plant resource with extensive biological activities including anti-cancer, anti-oxidation, and anti-inflammation activities. This work aims to study further the cytotoxic constituents from Dryopteris fragrans. In this work, two new phenolic derivatives known as dryofragone (1 [...] Read more.
Dryopteris fragrans is a valuable medicinal plant resource with extensive biological activities including anti-cancer, anti-oxidation, and anti-inflammation activities. This work aims to study further the cytotoxic constituents from Dryopteris fragrans. In this work, two new phenolic derivatives known as dryofragone (1) and dryofracoumarin B (2) with six known compounds (38) were isolated from the petroleum ether fraction of the methanol extract of the aerial parts of Dryopteris fragrans (L.) Schott by two round cytotoxicity-guided tracking with the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and cell counting kit-8 (CCK-8) assay. Their structures were elucidated by the extensive spectroscopic analysis (1H-NMR, 13C-NMR, and two dimensions NMR), chemical derivatization, and comparison with data reported in the literature. All the isolates were evaluated for their cytotoxicity against nine cancer cell lines as well as their in vitro immunomodulatory activity. The results showed that compounds have a modest cytotoxicity toward human HeLa cell line with IC50 value below 30 μM and compounds 4 and 5 may modulate immunity to affect the growth of tumor cells. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Graphical abstract

Review

Jump to: Research

Open AccessReview
Carotenoids: How Effective Are They to Prevent Age-Related Diseases?
Molecules 2019, 24(9), 1801; https://doi.org/10.3390/molecules24091801
Received: 28 March 2019 / Revised: 3 May 2019 / Accepted: 6 May 2019 / Published: 9 May 2019
PDF Full-text (1682 KB) | HTML Full-text | XML Full-text
Abstract
Despite an increase in life expectancy that indicates positive human development, a new challenge is arising. Aging is positively associated with biological and cognitive degeneration, for instance cognitive decline, psychological impairment, and physical frailty. The elderly population is prone to oxidative stress due [...] Read more.
Despite an increase in life expectancy that indicates positive human development, a new challenge is arising. Aging is positively associated with biological and cognitive degeneration, for instance cognitive decline, psychological impairment, and physical frailty. The elderly population is prone to oxidative stress due to the inefficiency of their endogenous antioxidant systems. As many studies showed an inverse relationship between carotenoids and age-related diseases (ARD) by reducing oxidative stress through interrupting the propagation of free radicals, carotenoid has been foreseen as a potential intervention for age-associated pathologies. Therefore, the role of carotenoids that counteract oxidative stress and promote healthy aging is worthy of further discussion. In this review, we discussed the underlying mechanisms of carotenoids involved in the prevention of ARD. Collectively, understanding the role of carotenoids in ARD would provide insights into a potential intervention that may affect the aging process, and subsequently promote healthy longevity. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Figure 1

Open AccessReview
Genuine and Sequestered Natural Products from the Genus Orobanche (Orobanchaceae, Lamiales)
Molecules 2018, 23(11), 2821; https://doi.org/10.3390/molecules23112821
Received: 10 October 2018 / Revised: 26 October 2018 / Accepted: 28 October 2018 / Published: 30 October 2018
PDF Full-text (14762 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The present review gives an overview about natural products from the holoparasitic genus Orobanche (Orobanchaceae). We cover both genuine natural products as well as compounds sequestered by Orobanche taxa from their host plants. However, the distinction between these two categories is not always [...] Read more.
The present review gives an overview about natural products from the holoparasitic genus Orobanche (Orobanchaceae). We cover both genuine natural products as well as compounds sequestered by Orobanche taxa from their host plants. However, the distinction between these two categories is not always easy. In cases where the respective authors had not indicated the opposite, all compounds detected in Orobanche taxa were regarded as genuine Orobanche natural products. From the about 200 species of Orobanche s.l. (i.e., including Phelipanche) known worldwide, only 26 species have so far been investigated phytochemically (22 Orobanche and four Phelipanche species), from 17 Orobanche and three Phelipanche species defined natural products (and not only natural product classes) have been reported. For two species of Orobanche and one of Phelipanche dedicated studies have been performed to analyze the phenomenon of natural product sequestration by parasitic plants from their host plants. In total, 70 presumably genuine natural products and 19 sequestered natural products have been described from Orobanche s.l.; these form the basis of 140 chemosystematic records (natural product reports per taxon). Bioactivities described for Orobanche s.l. extracts and natural products isolated from Orobanche species include in addition to antioxidative and anti-inflammatory effects, e.g., analgesic, antifungal and antibacterial activities, inhibition of amyloid β aggregation, memory enhancing effects as well as anti-hypertensive effects, inhibition of blood platelet aggregation, and diuretic effects. Moreover, muscle relaxant and anti-spasmodic effects as well as anti-photoaging effects have been described. Full article
(This article belongs to the Special Issue Natural Products and Drug Discovery)
Figures

Figure 1

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top