1
|
Yang JN, Yi JL, Zou JH, Chen ZX, Chen GY, Hui Y, Sun ZF, Chen WH. Flavonoidal alkaloids from the flowers of Chromolaena odorata (L.) R.M.King & H.Rob. Nat Prod Res 2023:1-9. [PMID: 37081808 DOI: 10.1080/14786419.2023.2202395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
A pair of epimers of flavonoid alkaloids, with a pyrrolidone moiety, 2S,5''R-eupodoratin A (1), 2S,5''S-eupodoratin A (2), together with two known analogues, drahebephin A (3), drahebephin B (4), were isolated from the flowers of Chromolaena odorata (L.) R.M.King & H.Rob. Their structures were elucidated on the basis of HR-ESI-MS, 1D/2D NMR spectral analyses. The absolute configuration of compounds (1) and (2) was determined by its experimental and calculated electronic circular dichroism (ECD) spectra. All compounds were isolated from the Asteraceae family for the first time. The ABTS·+ scavenging activity of compound (4) reached 93.56% at a concentration of 0.5 mM, while the scavenging capacity of positive control Trolox was 55.94%. In addition, all compounds show moderate antimicrobial activity against Escherichia coli (ATCC, 337304), Staphylococcus aureus (ATCC, 337371) and Candida albicans (ATCC, 186382) with a MIC value of more than 50 µg/mL.
Collapse
Affiliation(s)
- Jian-Ni Yang
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Ji-Ling Yi
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Jing-Hua Zou
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Zhao-Xia Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Guang-Ying Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Yang Hui
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| | - Zhen-Fan Sun
- Key Laboratory of Medicinal and Edible Plants Resources of Hainan Province, Hainan Vocational University of Science and Technology, Haikou, P.R. China
| | - Wen-Hao Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P.R. China
| |
Collapse
|
2
|
Bitchagno GTM, Nchiozem-Ngnitedem VA, Melchert D, Fobofou SA. Demystifying racemic natural products in the homochiral world. Nat Rev Chem 2022; 6:806-822. [PMID: 37118098 PMCID: PMC9562063 DOI: 10.1038/s41570-022-00431-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2022] [Indexed: 12/03/2022]
Abstract
Natural products possess structural complexity, diversity and chirality with attractive functions and biological activities that have significantly impacted drug discovery initiatives. Chiral natural products are abundant in nature but rarely occur as racemates. The occurrence of natural products as racemates is very intriguing from a biosynthetic point of view; as enzymes are chiral molecules, enzymatic reactions generating natural products should be stereospecific and lead to single-enantiomer products. Despite several reports in the literature describing racemic mixtures of stereoisomers isolated from natural sources, there has not been a comprehensive review of these intriguing racemic natural products. The discovery of many more natural racemates and their potential enzymatic sources in recent years allows us to describe the distribution and chemical diversity of this ‘class of natural products’ to enrich discussions on biosynthesis. In this Review, we describe the chemical classes, occurrence and distribution of pairs of enantiomers in nature and provide insights about recent advances in analytical methods used for their characterization. Special emphasis is on the biosynthesis, including plausible enzymatic and non-enzymatic formation of natural racemates, and their pharmacological significance. ![]()
Racemic natural products display a wealth of bioactivities and chemical diversity. Their derivation from intriguing racemization processes, through enzymatic or non-enzymatic pathways, are discussed here, as well as their pharmacological properties and the analytical techniques developed for their identification, resolution and characterization.
Collapse
|
3
|
Li C, Dang J, Lv Y, Fang Y, Ma C, Wang Q, Li G. The Isolation and Preparation of Samwinol from Dracocephalum heterophyllum and Prevention on Aβ 25-35-Induced Neuroinflammation in PC-12 Cells. Int J Mol Sci 2022; 23:ijms231911572. [PMID: 36232874 PMCID: PMC9570221 DOI: 10.3390/ijms231911572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/21/2022] [Accepted: 09/27/2022] [Indexed: 02/06/2023] Open
Abstract
Dracocephalum heterophyllum (D. heterophyllum) is a traditional Chinese Tibetan medicine that has been used for the treatment of lymphitis, hepatitis, and bronchitis. However, only a few selected chemical components are currently obtained from D. heterophyllum, which limits its further pharmacological applications. In this study, we have obtained samwinol from D. heterophyllum by medium- and high-pressure liquid chromatography separation for the first time. Thereafter, we investigated the protective actions of samwinol against amyloid beta protein fragment 25-35 (Aβ25-35) induced neurotoxicity in cultured rat pheochromocytoma PC-12 cells and explored its underlying mechanisms of action. The results indicated that samwinol could increase cell viability and inhibit the production of reactive oxygen species (ROS) and mitochondria-derived ROS, as assessed by MTT assay, Giemsa staining, and flow cytometry assay. Through Western blot analysis, it was found that samwinol substantially inhibited the phosphorylation of ERK(1/2) and promoted the expression of HO-1 and Nrf2. The data obtained from molecular docking were also consistent with the above conclusions. All of these results showed that samwinol from D. heterophyllum can display significant anti-neuroinflammatory and antioxidant activities in vitro, which are associated with the suppression of ERK/AKT phosphorylation and the activation of the Nrf2/HO-1 signaling pathway. In the future, additional in-depth mechanism studies will be carried out to provide more evidence for the potential of samwinol in the treatment of Alzheimer's disease.
Collapse
Affiliation(s)
- Chengzhao Li
- Center for Mitochondria and Healthy Aging, College of Life Sciences, Yantai University, Yantai 264005, China
| | - Jun Dang
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences, Northwest Institute of Plateau Biology, Xining 810001, China
| | - Yue Lv
- Center for Mitochondria and Healthy Aging, College of Life Sciences, Yantai University, Yantai 264005, China
| | - Yan Fang
- Center for Mitochondria and Healthy Aging, College of Life Sciences, Yantai University, Yantai 264005, China
| | - Chengjun Ma
- Center for Mitochondria and Healthy Aging, College of Life Sciences, Yantai University, Yantai 264005, China
| | - Qilan Wang
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences, Northwest Institute of Plateau Biology, Xining 810001, China
- Correspondence: (Q.W.); (G.L.)
| | - Gang Li
- Center for Mitochondria and Healthy Aging, College of Life Sciences, Yantai University, Yantai 264005, China
- Correspondence: (Q.W.); (G.L.)
| |
Collapse
|
4
|
Huang MJ, Wang JC, Shen SM, Si JY, Guo YW. Stereochemical insights into neuroprotective alkaloids from the aerial parts of Emilia sonchifolia. Fitoterapia 2022; 162:105267. [PMID: 35961597 DOI: 10.1016/j.fitote.2022.105267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/05/2022] [Accepted: 08/07/2022] [Indexed: 11/18/2022]
Abstract
A new alkaloid featured with a dibenz[c,e]azepin-5-one scaffold, namely emililactam A (3), together with a known pyrrolidine alkaloid (emilisonchine, 1) and a known flavonoid alkaloid [8-(2″-pyrrolidinone-5″-yl)-quercetin, 2] were isolated from the aerial parts of Emilia sonchifolia. Compounds 1 and 2 were isolated as racemic forms which were further separated, for the first time, to their corresponding enantiomers [(+)-1/(-)-1 and (+)-2/(-)-2], respectively, by using chiral-phase HPLC. The structure of new compound 3 was elucidated by extensive spectroscopic analysis. In addition, the absolute configurations of optically pure (+)-1/(-)-1 and (+)-2/(-)-2 were determined by the time-dependent density functional theory electronic circular dichroism (TDDFT-ECD) calculations. In an in vitro bioassay, compounds (+)-1, (-)-1, (±)-1, and 3 exhibited moderate neuroprotective effects against corticosterone-induced injuries of PC12 cells.
Collapse
Affiliation(s)
- Ming-Jin Huang
- College of Agriculture, Guizhou University, Guiyang 550025, China; Dendrobium Research Laboratory, Guizhou University, Guiyang 550025, China; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jun-Chi Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
| | - Shou-Mao Shen
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Pharmacy, Yancheng Teachers University, Yancheng 224007, China
| | - Jian-Yong Si
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China.
| | - Yue-Wei Guo
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| |
Collapse
|
5
|
Abstract
The health benefits of Dracocephalum heterophyllum are widely reported in traditional Tibetan medicines, but the reported chemical composition is limited, probably due to difficulties in separating and purifying compounds. In this study, antioxidative phenylethanoids were isolated from an extract of Dracocephalum heterophyllum using medium- and high-pressure liquid chromatography, coupled with on-line HPLC–1,1-diphenyl-2-picrylhydrazyl recognition. Firstly, crude samples (1.3 kg) of Dracocephalum heterophyllum were pretreated via silica gel medium-pressure liquid chromatography to yield 994.0 g of Fr2, of which 10.8 g was then pretreated via MCI GEL®CHP20P medium-pressure liquid chromatography. The resulting Fr23 and Fr25 were further separated and purified using high-pressure liquid chromatography, and yielded 8.08 mg of Fr2391, 9.76 mg of Fr2551, 16.09 mg of Fr2581, and 8.75 mg of Fr2582. Furthermore, analysis of the purity and structures of the phenylethanoids suggested that Fr2391, Fr2551, Fr2581, and Fr2582 corresponded to decaffeoylverbascoside, rosmarinic acid, acteoside, and 2′-O-acetylplantamajoside, respectively, with all being over 95% pure. Finally, the antioxidant potential of the compounds was explored based on their ability to scavenge 1,1-diphenyl-2-picrylhydrazine, as well as through molecular docking of proteins related to antioxidant pathways. Altogether, our findings revealed that the proposed method is promising for separating pure antioxidative phenylethanoids from other natural compounds.
Collapse
|
6
|
Gerasimova EL, Gazizullina ER, Borisova MV, Igdisanova DI, Nikiforov EA, Moseev TD, Varaksin MV, Chupakhin ON, Charushin VN, Ivanova AV. Design and Antioxidant Properties of Bifunctional 2 H-Imidazole-Derived Phenolic Compounds-A New Family of Effective Inhibitors for Oxidative Stress-Associated Destructive Processes. Molecules 2021; 26:molecules26216534. [PMID: 34770943 PMCID: PMC8588064 DOI: 10.3390/molecules26216534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
The synthesis of inhibitors for oxidative stress-associated destructive processes based on 2H-imidazole-derived phenolic compounds affording the bifunctional 2H-imidazole-derived phenolic compounds in good-to-excellent yields was reported. In particular, a series of bifunctional organic molecules of the 5-aryl-2H-imidazole family of various architectures bearing both electron-donating and electron-withdrawing substituents in the aryl fragment along with the different arrangements of the hydroxy groups in the polyphenol moiety, namely derivatives of phloroglucinol, pyrogallol, hydroxyquinol, including previously unknown water-soluble molecules, were studied. The structural and antioxidant properties of these bifunctional 5-aryl-2H-imidazoles were comprehensively studied. The redox transformations of the synthesized compounds were carried out. The integrated approach based on single and mixed mechanisms of antioxidant action, namely the AOC, ARC, Folin, and DPPH assays, were applied to estimate antioxidant activities. The relationship “structure-antioxidant properties” was established for each of the antioxidant action mechanisms. The conjugation effect was shown to result in a decrease in the mobility of the hydrogen atom, thus complicating the process of electron transfer in nearly all cases. On the contrary, the conjugation in imidazolyl substituted phloroglucinols was found to enhance their activity through the hydrogen transfer mechanism. Imidazole-derived polyphenolic compounds bearing the most electron-withdrawing functionality, namely the nitro group, were established to possess the higher values for both antioxidant and antiradical capacities. It was demonstrated that in the case of phloroglucinol derivatives, the conjugation effect resulted in a significant increase in the antiradical capacity (ARC) for a whole family of the considered 2H-imidazole-derived phenolic compounds in comparison with the corresponding unsubstituted phenols. Particularly, conjugation of the polyphenolic subunit with 2,2-dimethyl-5-(4-nitrophenyl)-2H-imidazol-4-yl fragment was shown to increase ARC from 2.26 to 5.16 (104 mol-eq/L). This means that the considered family of compounds is capable of exhibiting an antioxidant activity via transferring a hydrogen atom, exceeding the activity of known natural polyphenolic compounds.
Collapse
Affiliation(s)
- Elena L. Gerasimova
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Elena R. Gazizullina
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Maria V. Borisova
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Dinara I. Igdisanova
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Egor A. Nikiforov
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Timofey D. Moseev
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
| | - Mikhail V. Varaksin
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
- Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russia
| | - Oleg N. Chupakhin
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
- Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russia
| | - Valery N. Charushin
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
- Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russia
| | - Alla V. Ivanova
- Institute of Chemical Engineering, Ural Federal University, 620002 Ekaterinburg, Russia; (E.L.G.); (E.R.G.); (M.V.B.); (D.I.I.); (E.A.N.); (T.D.M.); (M.V.V.); (O.N.C.); (V.N.C.)
- Correspondence: ; Tel.: +7-(343)-3759756
| |
Collapse
|
7
|
Moseev TD, Nikiforov EA, Varaksin MV, Charushin VN, Chupakhin ON. Metal-Free C-H/C-H Coupling of 2 H-Imidazole 1-Oxides with Polyphenols toward Imidazole-Linked Polyphenolic Compounds. J Org Chem 2021; 86:13702-13710. [PMID: 34519203 DOI: 10.1021/acs.joc.1c01796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The methodology of nucleophilic substitution of hydrogen (SNH) was successfully applied as a convenient synthetic tool to afford azaheterocyclic derivatives of phenols of various architectures. A series of 26 novel imidazole-linked polyphenolic compounds were first prepared in 72-95% yields through the direct metal-free C-H/C-H coupling of polyphenols with 2H-imidazole 1-oxides. Comprehensive studies on the reaction condition optimization, scope, and limitations enabled the development of a straightforward method toward novel bifunctional derivatives bearing both phenolic and imidazole scaffolds of particular interest in the design of challenging molecules for versatile applications in medicinal chemistry and materials science.
Collapse
Affiliation(s)
- Timofey D Moseev
- Ural Federal University, 19 Mira Str., 620002 Ekaterinburg, Russia
| | - Egor A Nikiforov
- Ural Federal University, 19 Mira Str., 620002 Ekaterinburg, Russia
| | - Mikhail V Varaksin
- Ural Federal University, 19 Mira Str., 620002 Ekaterinburg, Russia.,Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 22 S. Kovalevskaya Str., 620990 Ekaterinburg, Russia
| | - Valery N Charushin
- Ural Federal University, 19 Mira Str., 620002 Ekaterinburg, Russia.,Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 22 S. Kovalevskaya Str., 620990 Ekaterinburg, Russia
| | - Oleg N Chupakhin
- Ural Federal University, 19 Mira Str., 620002 Ekaterinburg, Russia.,Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, 22 S. Kovalevskaya Str., 620990 Ekaterinburg, Russia
| |
Collapse
|
8
|
|
9
|
Leucoflavonine, a new bioactive racemic flavoalkaloid from the leaves of Leucosceptrum canum. Bioorg Med Chem 2019; 27:442-446. [PMID: 30579802 DOI: 10.1016/j.bmc.2018.12.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/11/2018] [Accepted: 12/14/2018] [Indexed: 01/23/2023]
Abstract
A new flavoalkaloid racemate, leucoflavonine (1), together with its flavonoid precursor pectolinarigenin (2), was isolated from the leaves of Leucosceptrum canum collected from Tibet. Its structure was established by comprehensive spectroscopic analysis. Chrial separation of the enantiomers of 1 was achieved, and their absolute configurations were determined as S-(+)- and R-(-)-leucoflavonines ((+)-1a and (-)-1b) by comparison of their computational and experimental optical rotations. Biological assays indicated that both (+)-1a and (-)-1b exhibited inhibitory activity against acetylchlorinesterase (AChE) in vitro (IC50 = 68.0 ± 8.6 and 18.3 ± 1.8 μM, respectively). Moreover, (-)-1b displayed cytotoxicity against human hepatoma cells HepG2 (IC50 = 52.9 ± 3.6 μM), and inhibited the production of interleukelin-2 (IL-2) in Jurkat cells (IC50 = 16.5 ± 0.9 μM), while (+)-1a showed no obvious activity in these assays.
Collapse
|
10
|
Li YR, Li GH, Zhou MX, Xiang L, Ren DM, Lou HX, Wang XN, Shen T. Discovery of natural flavonoids as activators of Nrf2-mediated defense system: Structure-activity relationship and inhibition of intracellular oxidative insults. Bioorg Med Chem 2018; 26:5140-5150. [PMID: 30227999 DOI: 10.1016/j.bmc.2018.09.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/01/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022]
Abstract
Continuous overproduction of reactive oxygen species (ROS), termed as oxidative stress, plays a crucial role in the onset and progression of many human diseases. Activation of nuclear transcription factor erythroid 2-related factor (Nrf2) by small molecules could eliminate ROS, and thus block the pathogenesis of oxidative stress-induced diseases. In this study, a natural flavonoid library was established and tested for their potential Nrf2 inducing effects. Based on QR inducing effect of flavonoids, their structure-activity relationship (SAR) on Nrf2 induction was summarized, and twenty flavonoids were firstly identified to be potential activators of Nrf2-mediated defensive response. Then, 7-O-methylbiochanin A (7-MBA) was further investigated for its capability on the Nrf2 activation and prevention against oxidative insults in human lung epithelial cells. Further studies indicated that 7-MBA activated Nrf2 signaling pathway and protected human lung epithelial Beas-2B cells against sodium arsenite [As(III)]-induced cytotoxicity in an Nrf2-dependent manner. Activation of Nrf2 by 7-MBA upregulated intracellular antioxidant capacity, which was produced by enhancement of Nrf2 stabilization, blockage of Nrf2 ubiquitination, as well as Nrf2 phosphorylation by mitogen-activated protein kinase (MAPK), protein kinase C (PKC), protein kinase R-like endoplasmic reticulum kinase (PERK), and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). Taken together, 7-MBA is a novel isoflavone-type Nrf2 activator displaying potential preventive effect against oxidative damages in human lung epithelial cells.
Collapse
Affiliation(s)
- Yan-Ru Li
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Guo-Hui Li
- Department of Pharmacy, Jinan Maternity and Child Care Hospital, Jinan, PR China
| | - Ming-Xing Zhou
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Lan Xiang
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Dong-Mei Ren
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Hong-Xiang Lou
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xiao-Ning Wang
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Tao Shen
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China.
| |
Collapse
|
11
|
Preparative isolation of antioxidative compounds from Dracocephalum heterophyllum using off-line two-dimensional reversed-phase liquid chromatography/hydrophilic interaction chromatography guided by on-line HPLC-DPPH assay. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1095:267-274. [PMID: 30121456 DOI: 10.1016/j.jchromb.2018.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 08/06/2018] [Accepted: 08/10/2018] [Indexed: 01/23/2023]
Abstract
Traditional Tibetan medicine (TTM) has been valuable for the identification of new therapeutic leads. Nevertheless, reports about the chemical constituents of TTM are meager owing to the lack of suitable purification techniques. In this study, an off-line two-dimensional reversed-phase/hydrophilic interaction liquid chromatography (2D RP/HILIC) technique guided by on-line HPLC-DPPH has been established for the isolation of pure antioxidants from the extract of Dracocephalum heterophyllum. According to the chromatographic recognition outcome of the HPLC-DPPH system, the first-dimensional (1D) separation on the Megress C18 preparative column yielded 6 antioxidative fractions (61.4% recovery) from the ethyl acetate fraction (6.1 g). In the second-dimensional (2D) separation, a HILIC XAmide preparative column was employed. In total, 8 antioxidants were isolated from D. heterophyllum with a purity of >95%, which indicated the efficiency of the developed method to prepare antioxidative compounds with high purity from plant extracts. In addition, this method was highly efficient for the preparation of structural analogues of the antioxidative polyphenols and could be applied for the purification of structural analogues from other resources.
Collapse
|
12
|
Li X, Liu GJ, Zhang W, Zhou YL, Ling TJ, Wan XC, Bao GH. Novel Flavoalkaloids from White Tea with Inhibitory Activity against the Formation of Advanced Glycation End Products. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:4621-4629. [PMID: 29669412 DOI: 10.1021/acs.jafc.8b00650] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Two novel flavoalkaloids, (-)-6-(5'''- S)- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (ester-type catechin pyrrolidinone A, etc-pyrrolidinone A, 1), (-)-6-(5'''- R)- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (etc-pyrrolidinone B, 2), and new naturally occurring flavoalkaloids, (-)-8- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (etc-pyrrolidinone C, 3a, and etc- pyrrolidinone D, 3b), were isolated from white tea ( Camellia sinensis). Their structures were identified by extensive nuclear magnetic resonance spectra. The absolute configuration of compounds 1 and 2 was decided by comprehensive circular dichroism spectroscopic analyses. The isolated flavoalkaloids together with (-)-epigallocatechin- O-gallate (EGCG) were evaluated for their inhibition against the formation of advanced glycation end products, with IC50 values ranging from 10.3 to 25.3 μM. Ultra performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry detected these flavoalkaloids in both white tea and fresh tea leaves, which demonstrated the existence of a corresponding biosynthetic pathway in tea plants. Therefore, a possible pathway was proposed to involve deamination, decarboxylation, and spontaneously cyclization of l-theanine and then attachment of the product to EGCG to form the flavoalkaloids.
Collapse
Affiliation(s)
- Xiao Li
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Guang-Jin Liu
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Wei Zhang
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Yv-Long Zhou
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Tie-Jun Ling
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Xiao-Chun Wan
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| | - Guan-Hu Bao
- Natural Products Laboratory, International Joint Laboratory of Tea Chemistry and Health Effects, State Key Laboratory of Tea Plant Biology and Utilization , Anhui Agricultural University , Hefei , Anhui 230036 , People's Republic of China
| |
Collapse
|
13
|
Ilkei V, Hazai L, Antus S, Bölcskei H. Flavonoid Alkaloids: Isolation, Bioactivity, and Synthesis. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2018. [DOI: 10.1016/b978-0-444-64058-1.00008-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
|
14
|
Varaksin M, Moseev T, Chupakhin O, Charushin V, Trofimov B. Metal-free C–H functionalization of 2H-imidazole 1-oxides with pyrrolyl fragments in the design of novel azaheterocyclic ensembles. Org Biomol Chem 2017; 15:8280-8284. [PMID: 28944818 DOI: 10.1039/c7ob01999h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Novel pyrrolyl-2H-imidazoles have been synthesizedviametal-free C–H/C–H coupling reactions under mild conditions and in good to excellent yields.
Collapse
Affiliation(s)
- Mikhail Varaksin
- Ural Federal University
- 620002 Ekaterinburg
- Russia
- Institute of Organic Synthesis
- Ural Branch of the Russian Academy of Sciences
| | | | - Oleg Chupakhin
- Ural Federal University
- 620002 Ekaterinburg
- Russia
- Institute of Organic Synthesis
- Ural Branch of the Russian Academy of Sciences
| | - Valery Charushin
- Ural Federal University
- 620002 Ekaterinburg
- Russia
- Institute of Organic Synthesis
- Ural Branch of the Russian Academy of Sciences
| | - Boris Trofimov
- Irkutsk Institute of Chemistry
- Siberian Branch of the Russian Academy of Sciences
- 664033 Irkutsk
- Russia
| |
Collapse
|
15
|
Blair LM, Calvert MB, Sperry J. Flavoalkaloids-Isolation, Biological Activity, and Total Synthesis. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2016; 77:85-115. [PMID: 28212702 DOI: 10.1016/bs.alkal.2016.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The flavoalkaloids possess unique molecular frameworks that contain both a flavonoid and alkaloid component. Flavoalkaloids result from the convergence of distinct biosynthetic pathways, affording natural products that display a wide range of interesting biological activities that would not be expected for flavonoids or alkaloids alone. This chapter collates all the known flavoalkaloids up until early 2016, detailing their isolation, bioactivity, and successful total syntheses.
Collapse
|
16
|
Three pairs of diastereoisomeric flavanone glycosides from Viscum articulatum. Fitoterapia 2015; 102:156-62. [DOI: 10.1016/j.fitote.2015.03.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 03/02/2015] [Accepted: 03/06/2015] [Indexed: 11/22/2022]
|
17
|
Histochemical investigation and kinds of alkaloids in leaves of different developmental stages in Thymus quinquecostatus. ScientificWorldJournal 2014; 2014:839548. [PMID: 25101324 PMCID: PMC4102088 DOI: 10.1155/2014/839548] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/05/2014] [Accepted: 06/16/2014] [Indexed: 01/22/2023] Open
Abstract
Thymus quinquecostatus, with more medical value, is a kind of wild plants. In order to exploit and utilize this plant, we studied the species and locations of alkaloids in its leaves. In this paper, histochemical study of leaves at different developing stages was taken to localize the alkaloids. Meanwhile, the kinds and content of alkaloids in leaves were identified using GC-MS technique. It was found that there were two kinds of glandular trichomes, namely, peltate trichomes and capitate trichomes, on the surface of leaves, and their secretory cells could secrete alkaloids. Results showed that trichomes could secrete alkaloids as soon as the first pair of leaves formed, and there were altogether 18 kinds of alkaloids identified by GC-MS. Nearly all of these alkaloids of leaves at different developing stages were distinct from each other, except one, 3-methoxy-a-methyl-benzeneethanamine, persists at different developing stages with high concentration.
Collapse
|
18
|
Chiral separation of two diastereomeric pairs of enantiomers of novel alkaloid-lignan hybrids from Lobelia chinensis and determination of the tentative absolute configuration. J Chromatogr A 2013; 1311:134-9. [DOI: 10.1016/j.chroma.2013.08.085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/21/2013] [Accepted: 08/23/2013] [Indexed: 11/21/2022]
|