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Natural Products as Sources of New Drugs: In Memory of Professor Kuo-Hsiung Lee (1940-2021)

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

Deadline for manuscript submissions: closed (30 September 2022) | Viewed by 45080

Special Issue Editors


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Guest Editor
State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, 2A Nan Wei Road, Beijing 100050, China
Interests: medicinal chemistry; chemical biology; natural products chemistry; drug discovery; anticancer agent; neurodegenerative disease therapeutics; metabolic disease therapeutics

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Guest Editor
State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, Kunming 650201, China
Interests: natural products; structure elucidation; alkaloids; terpenoids; anti-cancer; anti-fungal; anti-inflammatory

Special Issue Information

Dear Colleagues,

Natural products (NPs) have been very important in drug discovery and still play a critical role, in many cases presenting new chemotypes with fascinating and complex chemical structures. As the need to pursue larger molecules than traditional small-molecule drugs to tackle new and difficult drug targets (such as protein–protein interaction) is increasing, NPs continuously attract a great deal of interest, even though the time-consuming and low-efficiency nature of NP study has not changed over the years. Besides, disobedience of the Rule of Five by many bioactive NPs prompts scientists to rethink how to achieve better pharmacokinetics through novel delivery technology.

Researchers from all disciplines involved in natural-products-based drug discovery and R&D are cordially invited to contribute original papers, short communications, and reviews to this Special Issue. In this Issue, NP, NP-like, and NP-inspired compound based drug discovery, structure optimization, biological evaluation and mechanism of action study, and drug delivery will be accepted for publication, whereas chemical studies (isolation, synthesis, etc.) without bioactivity assessment and biology-oriented works without any chemistry are discouraged.

This Special Issue is dedicated to the late Professor Kuo-Hsiung Lee (1940–2021), in recognition of his outstanding achievement in natural products chemistry, medicinal chemistry and pharmaceutical research.

Dr. Kuo-Hsiung Lee received his B.S. in pharmacy from Kaohsiung Medical University, Taiwan; and M.S. in pharmaceutical chemistry from Kyoto University, Japan; and a Ph.D. in medicinal chemistry from University of Minnesota, Minneapolis, USA in 1968. He was a postdoctoral scholar in organic chemistry at UCLA before he joined the faculty of the UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill as Assistant Professor in 1970, where he was then appointed as a Kenan Distinguished Professor and Director of the Natural Products Research Laboratories, until his retirement in 2021. He combined the fields of natural products and synthetic medicinal chemistry research to design and discover bioactive natural products and their analogs as drug candidates in clinical trials, including Berivimat, an HIV maturation inhibitor for anti-AIDS action, GL-331 and other podophyllotoxin analogs as anticancer agents and many others. He authored more than 950 research articles and more than 120 patents, received numerous awards including the Ernest H. Volwiler Award (the highest award of the American Association of Colleges of Pharmacy (AACP)) and was elected as an Academician of Academia Sinica and an American Association for the Advancement of Science (AAAS) Fellow.

Prof. Dr. Weishuo Fang
Prof. Dr. Yu Zhang
Guest Editors

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Keywords

Natural products

Structure elucidation

Medicinal chemistry

Computer-aided drug design

Chemical synthesis

Natural product-like compound

Natural product-inspired compound

Target-based assay

Phenotypic screening

Mechanism of action

In vivo efficacy

Drug delivery

Anti-cancer

Anti-HIV

Published Papers (15 papers)

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Research

Jump to: Review

11 pages, 5936 KiB  
Article
α-Linolenic Acid Screened by Molecular Docking Attenuates Inflammation by Regulating Th1/Th2 Imbalance in Ovalbumin-Induced Mice of Allergic Rhinitis
by Mengyue Ren, Yi Wang, Lin Lin, Shaoqiang Li and Qinhai Ma
Molecules 2022, 27(18), 5893; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27185893 - 11 Sep 2022
Cited by 5 | Viewed by 2021
Abstract
α-Linolenic acid (ALA) is a natural essential fatty acid widely found in plant seed oils and beans, which shows positive anti-inflammatory and antiallergic effects. In our previous study, ALA was proven to bind tightly to the seven protein targets closely associated with allergic [...] Read more.
α-Linolenic acid (ALA) is a natural essential fatty acid widely found in plant seed oils and beans, which shows positive anti-inflammatory and antiallergic effects. In our previous study, ALA was proven to bind tightly to the seven protein targets closely associated with allergic rhinitis (AR) by molecular docking, which indicates that ALA may have a potential role in the treatment of AR. A mouse model of AR induced by ovalbumin (OVA) was adopted in this study to explore the therapeutical effect and potential mechanism of ALA in treating AR. Results demonstrated that ALA remarkably relieved the nasal symptoms, reduced the OVA-sIgE level in the serum, relieved the histopathological injuries, and downregulated the mRNA expression levels of IL-6 and IL-1β in the nasal mucosa. ALA also remarkably moderated the imbalance of Th1/Th2 cells, increased the mRNA expression levels of T-bet and STAT1, and reduced GATA3 and STAT6. ALA was proven to have a substantial therapeutic effect on mice with AR, and the underlying mechanism was likely to be the regulation of Th1/Th2 imbalance through the JAK/T-bet/STAT1 and JAK/GATA3/STAT6 pathways. This study provides a specific experimental basis for the clinical use and drug development of ALA in the treatment of AR. Full article
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13 pages, 3590 KiB  
Article
Identification of Novel 4′-O-Demethyl-epipodophyllotoxin Derivatives as Antitumor Agents Targeting Topoisomerase II
by Wenli Xi, Hua Sun, Kenneth F. Bastow, Zhiyan Xiao and Kuo-Hsiung Lee
Molecules 2022, 27(15), 5029; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27155029 - 7 Aug 2022
Cited by 3 | Viewed by 1647
Abstract
C4 variation of 4′-O-demethyl-epipodophyllotoxin (DMEP) is an effective approach to optimize the antitumor spectra of this compound class. Accordingly, two series of novel DMEP derivatives were synthesized, and as expected, the antitumor spectra of these derivatives varied with different C4 substituents. [...] Read more.
C4 variation of 4′-O-demethyl-epipodophyllotoxin (DMEP) is an effective approach to optimize the antitumor spectra of this compound class. Accordingly, two series of novel DMEP derivatives were synthesized, and as expected, the antitumor spectra of these derivatives varied with different C4 substituents. Notably, most compounds showed significant inhibition against the etoposide (2)-resistant KBvin cells. Four of the compounds (11, 18, 27 and 28) induced protein-linked DNA break (PLDB) levels higher than those of GL-331 (6) and 2, and are assumed to be topoisomerase II (topo II) poisons more potent than 6 and 2. Compound 28, a potent topo II poison highly effective against KBvin cells, was further evaluated with a panel of tumor cells and was most active against HepG2. This compound also exhibited apparent in vivo antitumor efficacy in hepatoma 22 (H22) mouse model. The results indicated that C4 derivation of DMEP is a feasible approach to identify potent topo II inhibitors with optimized antitumor profiles. Full article
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15 pages, 2726 KiB  
Article
5-Demethoxy-10′-ethoxyexotimarin F, a New Coumarin with MAO-B Inhibitory Potential from Murraya exotica L.
by Zhen-Ru Xia-Hou, Xiao-Fei Feng, Yu-Fei Mei, Yin-Yan Zhang, Tong Yang, Jie Pan, Jing-Hua Yang and Yun-Song Wang
Molecules 2022, 27(15), 4950; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27154950 - 3 Aug 2022
Cited by 3 | Viewed by 1615
Abstract
Rutaceae plants are known for being a rich source of coumarins. Preliminary molecular docking showed that there was no significant difference for coumarins in Clausena and Murraya, both of which had high scoring values and showed good potential inhibitory activity to the [...] Read more.
Rutaceae plants are known for being a rich source of coumarins. Preliminary molecular docking showed that there was no significant difference for coumarins in Clausena and Murraya, both of which had high scoring values and showed good potential inhibitory activity to the MAO-B enzyme. Overall, 32 coumarins were isolated from Murraya exotica L., including a new coumarin 5-demethoxy-10′-ethoxyexotimarin F (1). Their structures were elucidated on the basis of a comprehensive analysis of 1D and 2D NMR and HRMS spectroscopic data, and the absolute configurations were assigned via a comparison of the specific rotations and the ECD exciton coupling method. The potential of new coumarin (1) as a selective inhibitor of MAO-B was initially evaluated through molecular docking and pharmacophore studies. Compound (1) showed selectivity for the MAO-B isoenzyme and inhibitory activity in the sub-micromolar range with an IC50 value of 153.25 ± 1.58 nM (MAO-B selectivity index > 172). Full article
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10 pages, 389 KiB  
Article
Efficacy of Biologically Active Food Supplements for People with Atherosclerotic Vascular Changes
by Natalia Pleshkova, Boisjoni Tokhiriyon, Andrei Vekovtsev, Valeriy Mikhailovich Poznyakovsky, Valentina Lapina, Madina Atlaevna Takaeva, Vladimir Nikolaevich Sorokopudov and Elena Valeryevna Karanina
Molecules 2022, 27(15), 4812; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27154812 - 27 Jul 2022
Cited by 4 | Viewed by 1600
Abstract
The current paper deals with the development of a new biologically active food supplement (BAFS) aimed at treating atherosclerosis. Since atherosclerosis is considered to be a disease of aging, the composition of the supplement includes such essential minerals as magnesium and potassium, which [...] Read more.
The current paper deals with the development of a new biologically active food supplement (BAFS) aimed at treating atherosclerosis. Since atherosclerosis is considered to be a disease of aging, the composition of the supplement includes such essential minerals as magnesium and potassium, which are commonly used to prevent atherosclerosis, as well as vitamins C, E and the B-group vitamins in order to address the needs of the elderly. The authors outline the supplement-manufacturing technology and discuss the clinical trial undertaken by patients, aged about 60 years, with peripheral atherosclerosis. The research methodology focuses on studying the effectiveness of the developed supplement by assessing the influence of the active ingredients on treating metabolic disorders. To establish the efficacy of the supplement, blood tests, ultrasound and physical examinations were applied. The combination therapy resulted in improved metabolism and an overall better performance of the cardiovascular system; therefore, the BASF can be recommended as part of combination therapy to prevent and treat atherosclerotic and age-related changes in blood vessels. Full article
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17 pages, 1934 KiB  
Article
Synthesis and Biological Evaluation of Novel Allobetulon/Allobetulin–Nucleoside Conjugates as AntitumorAgents
by Yanli Wang, Xiaowan Huang, Xiao Zhang, Jingchen Wang, Keyan Li, Guotao Liu, Kexin Lu, Xiang Zhang, Chengping Xie, Teresa Zheng, Yung-Yi Cheng and Qiang Wang
Molecules 2022, 27(15), 4738; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27154738 - 25 Jul 2022
Cited by 1 | Viewed by 1573
Abstract
Allobetulin is structurally similar tobetulinic acid, inducing the apoptosis of cancer cells with low toxicity. However, both of them exhibited weak antiproliferation against several tumor cell lines. Therefore, the new series of allobetulon/allobetulin–nucleoside conjugates 9a10i were designed and synthesized for potency [...] Read more.
Allobetulin is structurally similar tobetulinic acid, inducing the apoptosis of cancer cells with low toxicity. However, both of them exhibited weak antiproliferation against several tumor cell lines. Therefore, the new series of allobetulon/allobetulin–nucleoside conjugates 9a10i were designed and synthesized for potency improvement. Compounds 9b, 9e, 10a, and 10d showed promising antiproliferative activity toward six tested cell lines, compared to zidovudine, cisplatin, and oxaliplatin based on their antitumor activity results. Among them, compound 10d exhibited much more potent antiproliferative activity against SMMC-7721, HepG2, MNK-45, SW620, and A549 human cancer cell lines than cisplatin and oxaliplatin. In the preliminary study for the mechanism of action, compound 10d induced cell apoptosis and autophagy in SMMC cells, resulting in antiproliferation and G0/G1 cell cycle arrest by regulating protein expression levels of Bax, Bcl-2, and LC3. Consequently, the nucleoside-conjugated allobetulin (10d) evidenced that nucleoside substitution was a viable strategy to improve allobetulin/allobetulon’s antitumor activity based on our present study. Full article
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16 pages, 2667 KiB  
Article
Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba
by Kun Zhang, Mei Han, Xia Zhao, Xuelin Chen, Hanlei Wang, Jiyan Ni and Yumei Zhang
Molecules 2022, 27(11), 3381; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27113381 - 24 May 2022
Cited by 5 | Viewed by 2128
Abstract
Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP [...] Read more.
Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP assays were used for determining the antioxidant capability. The results of total flavonoids and phenolics contents showed that ethyl acetate fraction (EAF) possessed the highest flavonoids and phenolics with values of 159.7 ± 2.5 mg rutin equivalents/g and 107.6 ± 2.0 mg galic acid equivalents/g, respectively. The results of in vitro hypoglycemic activity showed that all samples had effective α-glucosidase inhibition capacities, and EAF possessed the best inhibitory effect with IC50 value of 1.58 ± 0.24 μg/mL. In addition, n-butanol fraction (NBF) significantly promoted the glucose uptake rate of 3T3-L1 adipocytes. HPLC-MS analysis and molecular docking results proved the interactions between candidates and α-glucosidase. The results of antioxidation capacities showed that EAF possessed the best antioxidation abilities with DPPH, ABTS, and FRAP. In summary, the hypoglycemic activity of PAH might be related to the inhibition of α-glucosidase (EAF > PEF > NBF) and the promotion of glucose uptake in 3T3-L1 adipocytes (NBF). Simultaneously, the antioxidation capacity of PAH might be related to the abundant contents of flavonoids and other phenolics (EAF > PEF > NBF). Full article
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17 pages, 7610 KiB  
Article
Cloning and Functional Characterization of Two Germacrene A Oxidases Isolated from Xanthium sibiricum
by Dong-Mei Xie, Qiang Zhang, Ling-Kai Xin, Guo-Kai Wang, Cong-Bin Liu and Min-Jian Qin
Molecules 2022, 27(10), 3322; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27103322 - 22 May 2022
Cited by 1 | Viewed by 2023
Abstract
Sesquiterpene lactones (STLs) from the cocklebur Xanthium sibiricum exhibit significant anti-tumor activity. Although germacrene A oxidase (GAO), which catalyzes the production of Germacrene A acid (GAA) from germacrene A, an important precursor of germacrene-type STLs, has been reported, the remaining GAOs corresponding to [...] Read more.
Sesquiterpene lactones (STLs) from the cocklebur Xanthium sibiricum exhibit significant anti-tumor activity. Although germacrene A oxidase (GAO), which catalyzes the production of Germacrene A acid (GAA) from germacrene A, an important precursor of germacrene-type STLs, has been reported, the remaining GAOs corresponding to various STLs’ biosynthesis pathways remain unidentified. In this study, 68,199 unigenes were studied in a de novo transcriptome assembly of X. sibiricum fruits. By comparison with previously published GAO sequences, two candidate X. sibiricum GAO gene sequences, XsGAO1 (1467 bp) and XsGAO2 (1527 bp), were identified, cloned, and predicted to encode 488 and 508 amino acids, respectively. Their protein structure, motifs, sequence similarity, and phylogenetic position were similar to those of other GAO proteins. They were most strongly expressed in fruits, according to a quantitative real-time polymerase chain reaction (qRT-PCR), and both XsGAO proteins were localized in the mitochondria of tobacco leaf epidermal cells. The two XsGAO genes were cloned into the expression vector for eukaryotic expression in Saccharomyces cerevisiae, and the enzyme reaction products were detected by gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) methods. The results indicated that both XsGAO1 and XsGAO2 catalyzed the two-step conversion of germacrene A (GA) to GAA, meaning they are unlike classical GAO enzymes, which catalyze a three-step conversion of GA to GAA. This cloning and functional study of two GAO genes from X. sibiricum provides a useful basis for further elucidation of the STL biosynthesis pathway in X. sibiricum. Full article
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16 pages, 2150 KiB  
Article
Antioxidant, Hypoglycemic and Molecular Docking Studies of Methanolic Extract, Fractions and Isolated Compounds from Aerial Parts of Cymbopogon citratus (DC.) Stapf
by Hanlei Wang, Ran Zhang, Kun Zhang, Xuelin Chen and Yumei Zhang
Molecules 2022, 27(9), 2858; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27092858 - 30 Apr 2022
Cited by 4 | Viewed by 2115
Abstract
Traditionally, Cymbopogon citratus is used to treat a variety of ailments, including cough, indigestion, fever, and diabetes. The previous chemical and bioactive research on C. citratus mainly focused on its volatile oil. In this study, 20 non-volatile known compounds were isolated from the [...] Read more.
Traditionally, Cymbopogon citratus is used to treat a variety of ailments, including cough, indigestion, fever, and diabetes. The previous chemical and bioactive research on C. citratus mainly focused on its volatile oil. In this study, 20 non-volatile known compounds were isolated from the dried aerial part of C. citratus, and their structures were elucidated by MS, NMR spectroscopy, and comparison with the published spectroscopic data. Among them, 16 compounds were reported for the first time from this plant. The screening results for antioxidant and α-glucosidase inhibitory activities indicated that compounds caffeic acid (5), 1-O-p-coumaroyl-3-O-caffeoylglycerol (8), 1,3-O-dicaffeoylglycerol (9) and luteolin-7-O-β-D-glucopyranoside (12) had potent antioxidant capacities, with IC50 values from 7.28 to 14.81 μM, 1.70 to 2.15 mol Trolox/mol and 1.31 to 2.42 mol Trolox/mol for DPPH, ABTS, and FRAP, respectively. Meanwhile, compounds 8 and 9 also exhibited significant inhibitory activities against α-glucosidase, with IC50 values of 11.45 ± 1.82 μM and 5.46 ± 0.25 μM, respectively, which were reported for the first time for their α-glucosidase inhibitory activities. The molecular docking result provided a molecular comprehension of the interaction between compounds (8 and 9) and α-glucosidase. The significant antioxidant and α-glucosidase inhibitory activities of compounds 8 and 9 suggested that they could be developed into antidiabetic drugs because of their potential regulatory roles on oxidative stress and digestive enzyme. Full article
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16 pages, 3833 KiB  
Article
Diterpenoid Alkaloids Isolated from Delphinium brunonianum and Their Inhibitory Effects on Hepatocytes Lipid Accumulation
by Huanhuan Ma, Yunxia Ma, Zeren Dawa, Yufeng Yao, Meiqi Wang, Kaihui Zhang, Chenchen Zhu, Fangle Liu and Chaozhan Lin
Molecules 2022, 27(7), 2257; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27072257 - 30 Mar 2022
Cited by 6 | Viewed by 1825
Abstract
This research aimed to excavate compounds with activity reducing hepatocytes lipid accumulation from Delphinium brunonianum. Four novel diterpenoid alkaloids, brunodelphinine B–E, were isolated from D. brunonianum together with eleven known diterpenoid alkaloids through a phytochemical investigation. Their structures were elucidated by comprehensive [...] Read more.
This research aimed to excavate compounds with activity reducing hepatocytes lipid accumulation from Delphinium brunonianum. Four novel diterpenoid alkaloids, brunodelphinine B–E, were isolated from D. brunonianum together with eleven known diterpenoid alkaloids through a phytochemical investigation. Their structures were elucidated by comprehensive spectroscopy methods including HR-ESI-MS, NMR, IR, UV, CD, and single-crystal X-ray diffraction analysis. The inhibitory effects of a total of 15 diterpenoid alkaloids on hepatocytes lipid accumulation were evaluated using 0.5 mM FFA (oleate/palmitate 2:1 ratio) to induce buffalo rat liver (BRL) cells by measuring the levels of triglyceride (TG), total cholesterol (TC), alanine transaminase (ALT), aspartate transaminase (AST), and the staining of oil red O. The results show that five diterpenoid alkaloids—brunodelphinine E (4), delbruline (5), lycoctonine (7), delbrunine (8), and sharwuphinine A (12)—exhibited significant inhibitory effects on lipid accumulation in a dose-dependent manner and without cytotoxicity. Among them, sharwuphinine A (12) displayed the strongest inhibition of hepatocytes lipid accumulation in vitro. Our research increased the understanding on the chemical composition of D. brunonianum and provided experimental and theoretical evidence for the active ingredients screened from this herbal medicine in the treatment of the diseases related to lipid accumulation, such as non-alcoholic fatty liver disease and hyperlipidemia. Full article
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17 pages, 4923 KiB  
Article
Plumbagin Alleviates Intracerebroventricular-Quinolinic Acid Induced Depression-like Behavior and Memory Deficits in Wistar Rats
by Mandeep Kumar Arora, Anish Ratra, Syed Mohammed Basheeruddin Asdaq, Ali A. Alshamrani, Abdulkhaliq J. Alsalman, Mehnaz Kamal, Ritu Tomar, Jagannath Sahoo, Jangra Ashok and Mohd Imran
Molecules 2022, 27(6), 1834; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27061834 - 11 Mar 2022
Cited by 7 | Viewed by 2412
Abstract
Plumbagin, a hydroxy-1,4-naphthoquinone, confers neuroprotection via antioxidant and anti-inflammatory properties. The present study aimed to assess the effect of plumbagin on behavioral and memory deficits induced by intrahippocampal administration of Quinolinic acid (QA) in male Wistar rats and reveal the associated mechanisms. QA [...] Read more.
Plumbagin, a hydroxy-1,4-naphthoquinone, confers neuroprotection via antioxidant and anti-inflammatory properties. The present study aimed to assess the effect of plumbagin on behavioral and memory deficits induced by intrahippocampal administration of Quinolinic acid (QA) in male Wistar rats and reveal the associated mechanisms. QA (300 nM/4 μL in Normal saline) was administered i.c.v. in the hippocampus. QA administration caused depression-like behavior (forced swim test and tail suspension tests), anxiety-like behavior (open field test and elevated plus maze), and elevated anhedonia behavior (sucrose preference test). Furthermore, oxidative–nitrosative stress (increased nitrite content and lipid peroxidation with reduction of GSH), inflammation (increased IL-1β), cholinergic dysfunction, and mitochondrial complex (I, II, and IV) dysfunction were observed in the hippocampus region of QA-treated rats as compared to normal controls. Plumbagin (10 and 20 mg/kg; p.o.) treatment for 21 days significantly ameliorated behavioral and memory deficits in QA-administered rats. Moreover, plumbagin treatment restored the GSH level and reduced the MDA and nitrite level in the hippocampus. Furthermore, QA-induced cholinergic dysfunction and mitochondrial impairment were found to be ameliorated by plumbagin treatment. In conclusion, our results suggested that plumbagin offers a neuroprotective potential that could serve as a promising pharmacological approach to mitigate neurobehavioral changes associated with neurodegeneration. Full article
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14 pages, 3783 KiB  
Article
Soyauxinine, a New Indolopyridoquinazoline Alkaloid from the Stem Bark of Araliopsis soyauxii Engl. (Rutaceae)
by Cédric Guy Tchatchouang Noulala, Judith Laure Nantchouang Ouete, Albert Fouda Atangana, Gabin Thierry Bitchagno Mbahbou, Ghislain Wabo Fotso, Hans-Georg Stammler, Bruno Ndjakou Lenta, Emmanuel Ngeufa Happi, Norbert Sewald and Bonaventure Tchaleu Ngadjui
Molecules 2022, 27(3), 1104; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27031104 - 7 Feb 2022
Cited by 3 | Viewed by 1808
Abstract
The chemical investigation of the total alkaloid extract (TAE) of the stem bark of Araliopsis soyauxii (Rutaceae) afforded an unreported indolopyridoquinazoline (compound 1) along with nine previously known alkaloids 210. In addition, six semi-synthetic derivatives 3ac, [...] Read more.
The chemical investigation of the total alkaloid extract (TAE) of the stem bark of Araliopsis soyauxii (Rutaceae) afforded an unreported indolopyridoquinazoline (compound 1) along with nine previously known alkaloids 210. In addition, six semi-synthetic derivatives 3ac, 4b, 5a and 6a were prepared by allylation and acetonidation of soyauxinium nitrate (5), edulinine (3), ribalinine (4) and arborinine (6). The structures and spectroscopic data of five of them are reported herein for the first time. The suggested mechanism for the formation of the new N-allylindolopyridoquinazoline 5a is presented. The structures of natural and derived compounds were determined employing extensive NMR and MS techniques. The absolute configuration of stereogenic centers in compounds 24 were determined using NOESY technique and confirmed by the single-crystal X-ray diffraction (SC-XRD) technique. The use of SC-XRD further enabled us to carry out a structural revision of soyauxinium chloride recently isolated from the same plant to soyauxinium nitrate (5). The TAE, fractions, compounds 17 and 9, and semi-synthetic derivatives 3ac, 4b, 5a and 6a were evaluated for their cytotoxic activity towards the cervix carcinoma cell line KB-3-1. No significant activity was recorded for most of the compounds except for 9, which showed moderate activity against the tested cancer cell lines. Full article
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Review

Jump to: Research

30 pages, 3763 KiB  
Review
Lead/Drug Discovery from Natural Resources
by Zhihong Xu, Barrett Eichler, Eytan A. Klausner, Jetty Duffy-Matzner and Weifan Zheng
Molecules 2022, 27(23), 8280; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27238280 - 28 Nov 2022
Cited by 10 | Viewed by 3634
Abstract
Natural products and their derivatives have been shown to be effective drug candidates against various diseases for many years. Over a long period of time, nature has produced an abundant and prosperous source pool for novel therapeutic agents with distinctive structures. Major natural-product-based [...] Read more.
Natural products and their derivatives have been shown to be effective drug candidates against various diseases for many years. Over a long period of time, nature has produced an abundant and prosperous source pool for novel therapeutic agents with distinctive structures. Major natural-product-based drugs approved for clinical use include anti-infectives and anticancer agents. This paper will review some natural-product-related potent anticancer, anti-HIV, antibacterial and antimalarial drugs or lead compounds mainly discovered from 2016 to 2022. Structurally typical marine bioactive products are also included. Molecular modeling, machine learning, bioinformatics and other computer-assisted techniques that are very important in narrowing down bioactive core structural scaffolds and helping to design new structures to fight against key disease-associated molecular targets based on available natural products are considered and briefly reviewed. Full article
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34 pages, 4077 KiB  
Review
Insight into the Progress on Natural Dyes: Sources, Structural Features, Health Effects, Challenges, and Potential
by Nannan Li, Qirou Wang, Jingna Zhou, Shuqin Li, Junyu Liu and Haixia Chen
Molecules 2022, 27(10), 3291; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27103291 - 20 May 2022
Cited by 22 | Viewed by 4855
Abstract
(1) Background: Dyes play an important role in food, medicine, textile, and other industries, which make human life more colorful. With the increasing demand for food safety, the development of natural dyes becomes more and more attractive. (2) Methods: The literature was searched [...] Read more.
(1) Background: Dyes play an important role in food, medicine, textile, and other industries, which make human life more colorful. With the increasing demand for food safety, the development of natural dyes becomes more and more attractive. (2) Methods: The literature was searched using the electronic databases PubMed, Web of Science, and SciFinder and this scoping review was carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). (3) Results: 248 articles were included in this review. This review summarizes the research progress on natural dyes in the last ten years. According to structural features, natural dyes mainly include carotenoids, polyphenols, porphyrins, and alkaloids, and some of the newest dyes are summarized. Some pharmacological activities of carotenoids, anthocyanin, curcumin, and betalains in the last 10 years are summarized, and the biological effects of dyes regarding illumination conditions. The disadvantages of natural dyes, including sources, cost, stability, and poor bioavailability, limit their application. Here, some feasible strategies (potential resources, biotechnology, new extraction and separation strategies, strategies for improving stability) are described, which will contribute to the development and utilization of natural dyes. (4) Conclusion: Natural dyes show health benefits and potential in food additives. However, it is necessary for natural dyes to pass toxicity tests and quality tests and receive many regulatory approvals before their final entry into the market as food colorants or as drugs. Full article
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25 pages, 11930 KiB  
Review
A Systematic Review of Orthosiphon stamineus Benth. in the Treatment of Diabetes and Its Complications
by Qirou Wang, Jia Wang, Nannan Li, Junyu Liu, Jingna Zhou, Pengwei Zhuang and Haixia Chen
Molecules 2022, 27(2), 444; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27020444 - 10 Jan 2022
Cited by 18 | Viewed by 4939
Abstract
(1) Background: Orthosiphon stamineus Benth. is a traditional medicine used in the treatment of diabetes and chronic renal failure in southern China, Malaysia, and Thailand. Diabetes is a chronic metabolic disease and the number of diabetic patients in the world is increasing. This [...] Read more.
(1) Background: Orthosiphon stamineus Benth. is a traditional medicine used in the treatment of diabetes and chronic renal failure in southern China, Malaysia, and Thailand. Diabetes is a chronic metabolic disease and the number of diabetic patients in the world is increasing. This review aimed to systematically review the effects of O. stamineus in the treatment of diabetes and its complications and the pharmacodynamic material basis. (2) Methods: This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the databases ScienceDirect, PubMed, and Web of Science. (3) Results: Thirty-one articles related to O. stamineus and diabetes were included. The mechanisms of O. stamineus in the treatment of diabetes and its complications mainly included inhibiting α-amylase and α-glucosidase activities, antioxidant and anti-inflammatory activities, regulating lipid metabolism, promoting insulin secretion, ameliorating insulin resistance, increasing glucose uptake, promoting glycolysis, inhibiting gluconeogenesis, promoting glucagon-likepeptide-1 (GLP-1) secretion and antiglycation activity. Phenolic acids, flavonoids and triterpenoids might be the main components for hypoglycemia effects in O. stamineus. (4) Conclusion: O. stamineus could be an antidiabetic agent to treat diabetes and its complications. However, it needs further study on a pharmacodynamic substance basis and the mechanisms of effective constituents. Full article
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20 pages, 1524 KiB  
Review
The Future of Carica papaya Leaf Extract as an Herbal Medicine Product
by Maywan Hariono, Jeffry Julianus, Ipang Djunarko, Irwan Hidayat, Lintang Adelya, Friska Indayani, Zerlinda Auw, Gabriel Namba and Pandu Hariyono
Molecules 2021, 26(22), 6922; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26226922 - 17 Nov 2021
Cited by 12 | Viewed by 9218
Abstract
Carica papaya (papaya) leaf extract has been used for a long time in a traditional medicine to treat fever in some infectious diseases such as dengue, malaria, and chikungunya. The development of science and technology has subsequently made it possible to provide evidence [...] Read more.
Carica papaya (papaya) leaf extract has been used for a long time in a traditional medicine to treat fever in some infectious diseases such as dengue, malaria, and chikungunya. The development of science and technology has subsequently made it possible to provide evidence that this plant is not only beneficial as an informal medication, but also that it has scientifically proven pharmacological and toxicological activities, which have led to its formal usage in professional health care systems. The development of formulations for use in nutraceuticals and cosmeceuticals has caused this product to be more valuable nowadays. The use of good manufacturing practice (GMP) standards, along with the ease of registering this product facilitated by policies of the national government, will absolutely increase the value of papaya leaf extract as a vital nutraceutical and cosmeceutical products in the near future. In this article, we review the potential of papaya leaf extract to be a high-value commodity in terms of its health effects as well as its industrial benefits. Full article
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