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Mándi A, Rimóczi A, Vasas A, Hohmann J, Swamy MMM, Monde K, Barta RA, Kicsák M, Komáromi I, Fehér K, Kurtán T. Testing the Simplified Molecular Dynamics Approach to Improve the Reproduction of ECD Spectra and Monitor Aggregation. Int J Mol Sci 2024; 25:6453. [PMID: 38928181 PMCID: PMC11204327 DOI: 10.3390/ijms25126453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 05/30/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
A simplified molecular-dynamics-based electronic circular dichroism (ECD) approach was tested on three condensed derivatives with limited conformational flexibility and an isochroman-2H-chromene hybrid, the ECD spectra of which could not be precisely reproduced by the conventional ECD calculation protocol. Application of explicit solvent molecules at the molecular mechanics (MD) level in the dynamics simulations and subsequent TDDFT-ECD calculation for the unoptimized MD structures was able to improve the agreements between experimental and computed spectra. Since enhancements were achieved even for molecules with limited conformational flexibility, deformations caused by the solvent molecules and multitudes of conformers produced with unoptimized geometries seem to be key factors for better agreement. The MD approach could confirm that aggregation of the phenanthrene natural product luzulin A had a significant contribution to a specific wavelength range of the experimental ECD. The MD approach has proved that dimer formation occurred in solution and this was responsible for the anomalous ECD spectrum. The scope and limitations of the method have also been discussed.
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Affiliation(s)
- Attila Mándi
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary; (A.R.); (R.A.B.); (M.K.); (T.K.)
| | - Aliz Rimóczi
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary; (A.R.); (R.A.B.); (M.K.); (T.K.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Andrea Vasas
- Institute of Pharmacognosy, University of Szeged, 6720 Szeged, Hungary; (A.V.); (J.H.)
- HUN-REN-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Judit Hohmann
- Institute of Pharmacognosy, University of Szeged, 6720 Szeged, Hungary; (A.V.); (J.H.)
- HUN-REN-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Mahadeva M. M. Swamy
- Faculty of Advanced Life Science, Hokkaido University, Kita 21, Nishi 11, Sapporo 001-0021, Japan; (M.M.M.S.); (K.M.)
| | - Kenji Monde
- Faculty of Advanced Life Science, Hokkaido University, Kita 21, Nishi 11, Sapporo 001-0021, Japan; (M.M.M.S.); (K.M.)
| | - Roland A. Barta
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary; (A.R.); (R.A.B.); (M.K.); (T.K.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Máté Kicsák
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary; (A.R.); (R.A.B.); (M.K.); (T.K.)
| | - István Komáromi
- Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Krisztina Fehér
- HUN-REN–UD Molecular Recognition and Interaction Research Group, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary; (A.R.); (R.A.B.); (M.K.); (T.K.)
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Kovács T, Lajter I, Kúsz N, Schelz Z, Bózsity-Faragó N, Borbás A, Zupkó I, Krupitza G, Frisch R, Hohmann J, Vasas A, Mándi A. Isolation and NMR Scaling Factors for the Structure Determination of Lobatolide H, a Flexible Sesquiterpene from Neurolaena lobata. Int J Mol Sci 2023; 24:ijms24065841. [PMID: 36982924 PMCID: PMC10052924 DOI: 10.3390/ijms24065841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
A new flexible germacranolide (1, lobatolide H) was isolated from the aerial parts of Neurolaena lobata. The structure elucidation was performed by classical NMR experiments and DFT NMR calculations. Altogether, 80 theoretical level combinations with existing 13C NMR scaling factors were tested, and the best performing ones were applied on 1. 1H and 13C NMR scaling factors were also developed for two combinations utilizing known exomethylene containing derivatives, and the results were complemented by homonuclear coupling constant (JHH) and TDDFT-ECD calculations to elucidate the stereochemistry of 1. Lobatolide H possessed remarkable antiproliferative activity against human cervical tumor cell lines with different HPV status (SiHa and C33A), induced cell cycle disturbance and exhibited a substantial antimigratory effect in SiHa cells.
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Affiliation(s)
- Tibor Kovács
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Ildikó Lajter
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Norbert Kúsz
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Zsuzsanna Schelz
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Noémi Bózsity-Faragó
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Anikó Borbás
- Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - István Zupkó
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Georg Krupitza
- Department of Pathology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Richard Frisch
- Institute for Ethnobiology, Playa Diana, San José GT-170, Guatemala
| | - Judit Hohmann
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
- ELKH-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Andrea Vasas
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
- ELKH-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary
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Bailly C. Naming of new natural products: Standard, pitfalls and tips-and-tricks. PHYTOCHEMISTRY 2022; 200:113250. [PMID: 35598790 DOI: 10.1016/j.phytochem.2022.113250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
Naming a newly discovered natural product (NP) is a pleasant but difficult exercise. In most cases, the NP name will be given with reference to the species of origin, be it a plant, a marine organism, a mammalian or microbial species. For a long time, the use of biologically-based trivial names has been recommended to identify the parental linkage between the product and the originating genus or species. But the recommendation is not always followed and a multiplicity of trivial names have been attributed to NP, based on locations (country, region, city), foods, music, animals, forenames, etc. Tips-and-tricks associated with the naming of NP are underlined here. Usually, NP are differentiated across a homogeneous chemical series with a letter (from the Latin or Greek alphabet), followed or not with a number. In other cases, the change of a single letter distinguishes a series of NP. Common pitfalls associated with the naming of NP are enumerated, including the complexity of names, use of synonyms, duplicated names, confusing names and inappropriate terminology. The difficulties regularly encountered with the naming of NP are discussed. Four essential recommendations are recalled: (i) a thorough analysis of the existing products to avoid duplicated names and confusion, (ii) the use of a biologically-based trivial name to retrace the origin of the product, (iii) the strict adherence to the codes of chemical nomenclature, and (iv) the preference for simple names to facilitate transmission. Naming a new NP is a rewarding task, which shall be performed with all due skill, care and diligence.
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Affiliation(s)
- Christian Bailly
- OncoWitan, Scientific Consulting Office, Lille, Wasquehal, 59290, France.
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Marcarino MO, Cicetti S, Zanardi MM, Sarotti AM. A critical review on the use of DP4+ in the structural elucidation of natural products: the good, the bad and the ugly. A practical guide. Nat Prod Rep 2021; 39:58-76. [PMID: 34212963 DOI: 10.1039/d1np00030f] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: 2015 up to the end of 2020Even in the golden age of NMR, the number of natural products being incorrectly assigned is becoming larger every day. The use of quantum NMR calculations coupled with sophisticated data analysis provides ideal complementary tools to facilitate the elucidation process in challenging cases. Among the current computational methodologies to perform this task, the DP4+ probability is a popular and widely used method. This updated version of Goodman's DP4 synergistically combines NMR calculations at higher levels of theory with the Bayesian analysis of both scaled and unscaled data. Since its publication in late 2015, the use of DP4+ to solve controversial natural products has substantially grown, with several predictions being confirmed by total synthesis. To date, the structures of more than 200 natural products were determined with the aid of DP4+. However, all that glitters is not gold. Besides its intrinsic limitations, on many occasions it has been improperly used with potentially important consequences on the quality of the assignment. Herein we present a critical revision on how the scientific community has been using DP4+, exploring the strengths of the method and how to obtain optimal results from it. We also analyze the weaknesses of DP4+, and the paths to by-pass them to maximize the confidence in the structural elucidation.
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Affiliation(s)
- Maribel O Marcarino
- Instituto de Química Rosario (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina.
| | - Soledad Cicetti
- Instituto de Química Rosario (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina.
| | - María M Zanardi
- Instituto de Ingeniería Ambiental, Química y Biotecnología Aplicada (INGEBIO), Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina, Av. Pellegrini 3314, Rosario 2000, Argentina.
| | - Ariel M Sarotti
- Instituto de Química Rosario (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina.
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Shen L, Zou XP, Li WS, Mándi A, Kurtán T, Wu J. Granatripodins A-B, limonoids featuring a Tricyclo[3.3.1.0 2,8]nonane motif: Absolute configuration and agonistic effects on human pregnane-X-receptor. Bioorg Chem 2021; 111:104888. [PMID: 33862473 DOI: 10.1016/j.bioorg.2021.104888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 01/10/2023]
Abstract
Two unprecedented limonoids incorporating a sterically encumbered cyclopropane ring, named granatripodins A (1) and B (2), featuring the presence of a tricyclo[3.3.1.02,8]nonane motif, were obtained from seeds of the Thai Xylocarpus granatum. The planar structures and absolute configurations of these limonoids were unambiguously established by NMR investigations, TDDFT-ECD and DFT-NMR calculations, and single-crystal X-ray diffraction analysis (Cu Kα). Most notably, granatripodin A (1) exhibited agonistic effects on human pregnane-X-receptor at the concentration of 100.0 nM. The biosynthetic origins of these limonoids via a radical cascade reaction are proposed. This study exemplifies a universal approach for the stereochemical assignment of polycyclic compounds with a cyclopropane-embedded cage scaffold.
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Affiliation(s)
- Li Shen
- Marine Drugs Research Center, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, PR China.
| | - Xiao-Peng Zou
- Marine Drugs Research Center, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, PR China
| | - Wan-Shan Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, PR China
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, PO Box 400, 4002 Debrecen, Hungary
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, PO Box 400, 4002 Debrecen, Hungary
| | - Jun Wu
- School of Pharmaceutical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou 510515, PR China; Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, PR China; Institute of Marine Biomedicine, Shenzhen Polytechnic, Shenzhen 518055, PR China.
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Ren YX, Zou XP, Li WS, Wu J, Shen L. Discovery of Thai mangrove tetranortriterpenoids as agonists of human pregnane-X-receptor and inhibitors against human carboxylesterase 2. Bioorg Chem 2020; 107:104599. [PMID: 33421954 DOI: 10.1016/j.bioorg.2020.104599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 10/22/2022]
Abstract
Human pregnane-X-receptor (hPXR) is considered to be the key target for the treatment of cholestasis and liver injury. Agonists of hPXR are potential drug leads. Potent and selective inhibitors of human carboxylesterase 2 (hCES2) could be utilized to alleviate the toxicity induced by ester drugs. In this work, fifteen new tetranortriterpenoids with structure diversity, named thaigranatins F-T (1-15), including four limonoids containing a C1-O-C29 bridge (1-4), four mexicanolides (5-8), three phragmalins (9-11), two limonoids belonging to the small group of trichiliton A (12-13), and two apotirucallanes (14-15), were isolated from seeds of the Thai mangrove, Xylocarpus granatum. The structures of these compounds were established by high resolution-electrospray ionization mass spectroscopy, extensive NMR spectroscopic investigations, single-crystal X-ray diffraction analyses, and the comparison of experimental electronic circular dichroism spectra. Most notably, thaigranatins L (7) and P (11) exhibited agonistic effects on hPXR at the concentration of 10.0 μM and 10.0 nM, respectively, whereas thaigranatins J (5), M (8), and T (15) showed inhibitory activities against hCES2 with IC50 values of 6.63, 11.35, and 5.05 μM, respectively. The 8α,30α-epoxy moiety of mexicanolide and the Δ8,14 double bond of phragmalin are pivotal for agonistic effects of these limonoids on hPXR, whereas the 6-OAc group of mexicanolide is crucial for its inhibitory activity against hCES2. Additionally, the flexible C-17-side-chain with appropriate hydroxy groups is considered to be important for the inhibitory activity of apotirucallane against hCES2.
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Affiliation(s)
- Yan-Xia Ren
- School of Pharmaceutical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou 510515, PR China
| | - Xiao-Peng Zou
- Marine Drugs Research Center, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, PR China
| | - Wan-Shan Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, PR China
| | - Jun Wu
- School of Pharmaceutical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou 510515, PR China; Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, PR China; Institute of Marine Biomedicine, Shenzhen Polytechnic, Shenzhen 518055, PR China.
| | - Li Shen
- Marine Drugs Research Center, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, PR China.
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