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Wu S, Tatsis EC. Specialized metabolism in St John's wort. CURRENT OPINION IN PLANT BIOLOGY 2024; 82:102625. [PMID: 39236592 DOI: 10.1016/j.pbi.2024.102625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 08/12/2024] [Accepted: 08/12/2024] [Indexed: 09/07/2024]
Abstract
The specialized metabolism of St. John's wort, Hypericum perforatum L., is a key focus in medicinal plant research due to its hallmark bioactive compounds hyperforin and hypericin. Known for its traditional medicinal uses dating back to ancient times, St. John's wort is currently used for mild depression therapy. Recent research works have shed light on the biosynthesis of various metabolites in this plant, such as flavonoids, xanthones, hyperforin, and hypericin. The elucidation of these pathways, along with the discovery of novel enzymes like hyperforin synthase, support the pharmaceutical research by enabling scalable production of bioactive compounds for the development of new drugs. Elucidation of the hyperforin biosynthesis based on single-cell RNA-seq is an approach that will be expanded and accelerate the gene discovery and full pathway reconstitution of plant specialized metabolites.
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Affiliation(s)
- Song Wu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Shanghai, China
| | - Evangelos C Tatsis
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; CEPAMS - CAS-JIC Centre of Excellence for Plant and Microbial Sciences, Shanghai, China.
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2
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Wu S, Morotti ALM, Yang J, Wang E, Tatsis EC. Single-cell RNA sequencing facilitates the elucidation of the complete biosynthesis of the antidepressant hyperforin in St. John's wort. MOLECULAR PLANT 2024; 17:1439-1457. [PMID: 39135343 DOI: 10.1016/j.molp.2024.08.003] [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: 07/25/2024] [Revised: 08/05/2024] [Accepted: 08/07/2024] [Indexed: 08/27/2024]
Abstract
Hyperforin is the compound responsible for the effectiveness of St. John's wort (Hypericum perforatum) as an antidepressant, but its complete biosynthetic pathway remains unknown. Gene discovery based on co-expression analysis of bulk RNA-sequencing data or genome mining failed to discover the missing steps in hyperforin biosynthesis. In this study, we sequenced the 1.54-Gb tetraploid H. perforatum genome assembled into 32 chromosomes with the scaffold N50 value of 42.44 Mb. By single-cell RNA sequencing, we identified a type of cell, "Hyper cells", wherein hyperforin biosynthesis de novo takes place in both the leaves and flowers. Through pathway reconstitution in yeast and tobacco, we identified and characterized four transmembrane prenyltransferases (HpPT1-4) that are localized at the plastid envelope and complete the hyperforin biosynthetic pathway. The hyperforin polycyclic scaffold is created by a reaction cascade involving an irregular isoprenoid coupling and a tandem cyclization. Our findings reveal how and where hyperforin is biosynthesized, enabling synthetic-biology reconstitution of the complete pathway. Thus, this study not only deepens our comprehension of specialized metabolism at the cellular level but also provides strategic guidance for elucidation of the biosynthetic pathways of other specializied metabolites in plants.
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Affiliation(s)
- Song Wu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Ana Luisa Malaco Morotti
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jun Yang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ertao Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Evangelos C Tatsis
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; CEPAMS - CAS-JIC Centre of Excellence for Plant and Microbial Science, Shanghai 200032, China.
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3
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Mazzotta S, Rositano V, Senaldi L, Bernardi A, Allegrini P, Appendino G. Scalemic natural products. Nat Prod Rep 2023; 40:1647-1671. [PMID: 37439042 DOI: 10.1039/d3np00014a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Covering: up to the end of 2022The area of scalemic natural products is often enigmatic from a mechanistic standpoint, since low optical purity is observed in compounds having multiple contiguous stereogenic centers resulting from mechanistically distinct biogenetic steps. A scalemic state is rarely the result of a sloppy enzymatic activity, rather resulting from the expression of antipodal enzymes/directing proteins or from the erosion of optical purity by enzymatic or spontaneous reactions. Evidence for these processes is critically reviewed, identifying the mechanisms most often associated to the enzymatic generation of scalemic natural products and also discussing analytical exploitations of natural products' scalemicity.
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Affiliation(s)
- Sarah Mazzotta
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Vincenzo Rositano
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- Indena SpA, Via Don Minzoni 6, 20049 Settala, MI, Italy
| | - Luca Senaldi
- Indena SpA, Via Don Minzoni 6, 20049 Settala, MI, Italy
| | - Anna Bernardi
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | | | - Giovanni Appendino
- Dipartimento di Scienze del Farmaco, Largo Donegani 2, 28100 Novara, Italy.
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de Araújo PR, Fonseca-Santos B, Kogawa AC, Salgado HRN, Chorilli M. A Review of Analytical Methods for the Determination of Hypericin in Foods, Herbal, Biological and Pharmaceutical Matrices. Curr Pharm Des 2020; 26:4648-4657. [DOI: 10.2174/1381612826666200531145624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/29/2020] [Indexed: 11/22/2022]
Abstract
Aims:
A review of analytical methods for the determination of hypericin in foods, herbal, biological
and pharmaceutical matrices.
Background:
Hypericin (HYP) is a naturally-occurring pigment obtained from some plants of the genus Hypericum.
Although HYP has been known for many years, it has recently attracted attention due to its varied biological
properties, such as anti-inflammatory and antidepressant activity and it is also an efficient photosensitizer.
Objective:
The objective of this review is to provide insights into the physicochemical properties of HYP, as well
as to report the analytical methods existing in the literature and official compendia for different matrices.
Methods:
The survey data were collected by Google Scholar® and Scopus® using keys terms.
Result:
Analytical methods involving HYP are mainly concerned with the quality control of pharmaceutical
preparations, foods, beverages, biological samples and drug delivery systems using different types of analysis
methods. Some difficulties have also been identified due to the physicochemical properties of HYP. It presents
great solubility in alkaline solutions, organic bases and common polar organic solvents.
Conclusion:
It can be analyzed by thin layer chromatography, spectrophotometry in the ultraviolet region, but the
most commonly used method is by HPLC. HYP presents monographs in the American, British and European
Pharmacopoeias, however, the methods of analysis are not yet harmonized.
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Affiliation(s)
- Patricia Rocha de Araújo
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Drugs and Medicines, Araraquara, SP, Brazil
| | - Bruno Fonseca-Santos
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Drugs and Medicines, Araraquara, SP, Brazil
| | - Ana Carolina Kogawa
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Drugs and Medicines, Araraquara, SP, Brazil
| | - Hérida Regina Nunes Salgado
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Drugs and Medicines, Araraquara, SP, Brazil
| | - Marlus Chorilli
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Drugs and Medicines, Araraquara, SP, Brazil
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Szymanski S, Majerz I. Aromaticity and Electron Density of Hypericin. JOURNAL OF NATURAL PRODUCTS 2019; 82:2106-2115. [PMID: 31348658 DOI: 10.1021/acs.jnatprod.8b00872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The influence of the substituents on the geometry of the central ring system of hypericin has been analyzed. Substitution that causes flattening of the hypericin central rings is connected with introducing the aromatic character of the empty rings. All the hypericin rings have an aromatic character illustrated by the Harmonic Oscillator Measure of Aromaticity (HOMA), Nucleus Independent Chemical Shift (NICS), Fluctuation Index (FLU), and Ellipticity Index (EL) indices. Quantum Theory of Atoms in Molecules (QTAIM) and Natural Bond Orbital (NBO) analyses performed on 7,14-dihydrophenanthro[1,10,9,8-opqra]perylene, its substituted analogues, and hypericin show an influence of this substitution on electron density of the central rings.
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Affiliation(s)
- Sebastian Szymanski
- Faculty of Pharmacy , Wroclaw Medical University , Borowska 211a , 50-556 Wroclaw , Poland
| | - Irena Majerz
- Faculty of Pharmacy , Wroclaw Medical University , Borowska 211a , 50-556 Wroclaw , Poland
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Siskos MG, Choudhary MI, Gerothanassis IP. Hydrogen Atomic Positions of O-H···O Hydrogen Bonds in Solution and in the Solid State: The Synergy of Quantum Chemical Calculations with ¹H-NMR Chemical Shifts and X-ray Diffraction Methods. Molecules 2017; 22:E415. [PMID: 28272366 PMCID: PMC6155303 DOI: 10.3390/molecules22030415] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/27/2017] [Accepted: 03/03/2017] [Indexed: 12/21/2022] Open
Abstract
The exact knowledge of hydrogen atomic positions of O-H···O hydrogen bonds in solution and in the solid state has been a major challenge in structural and physical organic chemistry. The objective of this review article is to summarize recent developments in the refinement of labile hydrogen positions with the use of: (i) density functional theory (DFT) calculations after a structure has been determined by X-ray from single crystals or from powders; (ii) ¹H-NMR chemical shifts as constraints in DFT calculations, and (iii) use of root-mean-square deviation between experimentally determined and DFT calculated ¹H-NMR chemical shifts considering the great sensitivity of ¹H-NMR shielding to hydrogen bonding properties.
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Affiliation(s)
- Michael G Siskos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - M Iqbal Choudhary
- H.E.J. Research Institute of Chemistry, International Center for Biological and Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
- H.E.J. Research Institute of Chemistry, International Center for Biological and Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
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Siskos MG, Choudhary MI, Tzakos AG, Gerothanassis IP. 1H ΝΜR chemical shift assignment, structure and conformational elucidation of hypericin with the use of DFT calculations – The challenge of accurate positions of labile hydrogens. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.10.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Charisiadis P, Kontogianni VG, Tsiafoulis CG, Tzakos AG, Siskos M, Gerothanassis IP. 1H-NMR as a structural and analytical tool of intra- and intermolecular hydrogen bonds of phenol-containing natural products and model compounds. Molecules 2014; 19:13643-82. [PMID: 25185070 PMCID: PMC6271058 DOI: 10.3390/molecules190913643] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 11/23/2022] Open
Abstract
Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2≤2 Hz) can be obtained under optimized experimental conditions which allow the application of 1H-13C HMBC-NMR experiments to reveal long range coupling constants of hydroxyl protons and, thus, to provide unequivocal assignment of the OH signals even in cases of complex polyphenol natural products. Intramolecular and intermolecular hydrogen bonds have a very significant effect on 1H OH chemical shifts which cover a region from 4.5 up to 19 ppm. Solvent effects on -OH proton chemical shifts, temperature coefficients (Δδ/ΔT), OH diffusion coefficients, and nJ(13C, O1H) coupling constants are evaluated as indicators of hydrogen bonding and solvation state of phenol -OH groups. Accurate 1H chemical shifts of the OH groups can be calculated using a combination of DFT and discrete solute-solvent hydrogen bond interaction at relatively inexpensive levels of theory, namely, DFT/B3LYP/6-311++G (2d,p). Excellent correlations between experimental 1H chemical shifts and those calculated at the ab initio level can provide a method of primary interest in order to obtain structural and conformational description of solute-solvent interactions at a molecular level. The use of the high resolution phenol hydroxyl group 1H-NMR spectral region provides a general method for the analysis of complex plant extracts without the need for the isolation of the individual components.
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Affiliation(s)
- Pantelis Charisiadis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Vassiliki G Kontogianni
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | | | - Andreas G Tzakos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Michael Siskos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
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Ciogli A, Bicker W, Lindner W. Determination of enantiomerization barriers of hypericin and pseudohypericin by dynamic high-performance liquid chromatography on immobilized polysaccharide-type chiral stationary phases and off-column racemization experiments. Chirality 2010; 22:463-71. [PMID: 19644936 DOI: 10.1002/chir.20764] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Direct enantiomer separation of hypericin, pseudohypericin, and protohypericin was accomplished by high-performance liquid chromatography (HPLC) using immobilized polysaccharide-type chiral stationary phases (CSPs). Enantioselectivities up to 1.30 were obtained in the polar-organic elution mode whereby for hypericin and pseudohypericin Chiralpak IC [chiral selector being cellulose tris(3,5-dichlorophenylcarbamate)] and for protohypericin Chiralpak IA (chiral selector being the 3,5-dimethylphenylcarbamate of amylose) gave favorable results. Enantiomers were distinguished by on-line electronic circular dichroism detection. Optimized enantioselective chromatographic conditions were the basis for determining stereodynamic parameters of the enantiomer interconversion process of hypericin and pseudohypericin. Rate constants delivered by computational simulation of dynamic HPLC elution profiles (stochastic model, consideration of peak tailing) were used to calculate averaged enantiomerization barriers (DeltaG(enant)(#)) of 97.6-99.6 kJ/mol for both compounds (investigated temperature range 25-45 degrees C). Complementary variable temperature off-column (i.e., in solution) racemization experiments delivered DeltaG(enant)(#) = 97.1-98.0 kJ/mol (27-45 degrees C) for hypericin and DeltaG(enant)(#) = 98.9-101.4 kJ/mol (25-55 degrees C) for pseudohypericin. An activation enthalpy of DeltaH(#) = 86.0 kJ/mol and an activation entropy of DeltaS(#) = -37.7 J/(K mol) were calculated from hypericin racemization kinetics in solution, whereas for pseudohypericin these figures amounted to 74.1 kJ/mol and -82.6 J/(K mol), respectively. Although the natural phenanthroperylene quinone pigments hypericin and pseudohypericin as well as their biological precursor protohypericin are chiral and can be separated by enantioselective HPLC low enantiomerization barriers seem to prevent the occurrence of an excess of one enantiomer under typical physiological conditions--at least as long as stereoselective intermolecular interactions with other chiral entities are absent.
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Affiliation(s)
- Alessia Ciogli
- Department of Analytical Chemistry and Food Chemistry, University of Vienna, Vienna, Austria
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Kemami Wangun HV, Wood A, Fiorilla C, Reed JK, McCarthy PJ, Wright AE. Gymnochromes E and F, cytotoxic phenanthroperylenequinones from a deep-water crinoid, Holopus rangii. JOURNAL OF NATURAL PRODUCTS 2010; 73:712-5. [PMID: 20158243 PMCID: PMC2859091 DOI: 10.1021/np900526y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bioactivity-guided fractionation of metabolites from the crinoid Holopus rangii led to the discovery of two new phenanthroperylenequinone derivatives, gymnochromes E (1) and F (2). Gymnochrome E showed cytotoxic activity toward the NCI/ADR-Res with an IC(50) of 3.5 microM. It also inhibited histone deacetylase-1 with an IC(50) of 3.3 microM. Gymnochrome F was a moderate inhibitor of myeloid cell leukemia sequence 1 (MCL-1) binding to Bak. Two anthraquinone metabolites, emodic acid (4) and its new bromo derivative (5), were also isolated from the crinoid and show remarkable similarity to the phenanthroperylenequinone core, suggesting that these metabolites share the same polyketide biosynthetic pathway.
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Affiliation(s)
- Hilaire V. Kemami Wangun
- Harbor Branch Oceanographic Institute at Florida Atlantic University, Center for Marine Biomedical and Biotechnology Research, 5600 US 1 North, Fort Pierce, FL 34946
| | - Alexander Wood
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139
| | | | - John K. Reed
- Harbor Branch Oceanographic Institute at Florida Atlantic University, Center for Marine Biomedical and Biotechnology Research, 5600 US 1 North, Fort Pierce, FL 34946
| | - Peter J. McCarthy
- Harbor Branch Oceanographic Institute at Florida Atlantic University, Center for Marine Biomedical and Biotechnology Research, 5600 US 1 North, Fort Pierce, FL 34946
| | - Amy E. Wright
- Harbor Branch Oceanographic Institute at Florida Atlantic University, Center for Marine Biomedical and Biotechnology Research, 5600 US 1 North, Fort Pierce, FL 34946
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1H NMR determination of hypericin and pseudohypericin in complex natural mixtures by the use of strongly deshielded OH groups. Anal Chim Acta 2007; 607:219-26. [PMID: 18190811 DOI: 10.1016/j.aca.2007.11.040] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/19/2007] [Accepted: 11/20/2007] [Indexed: 11/21/2022]
Abstract
The (1)H NMR spectra of the commercially available compounds hypericin and its derivative pseudohypericin in CD(3)OH solutions indicate significantly deshielded signals in the region of 14-15 ppm. These resonances are attributed to the peri hydroxyl protons OH(6), OH(8) and OH(1), OH(13) of hypericins which participate in a strong six-membered ring intramolecular hydrogen bond with CO(7) and CO(14), respectively, and therefore, they are strongly deshielded. In the present work, we demonstrate that one-dimensional (1)H NMR spectra of hypericin and pseudohypericin, in Hypericum perforatum extracts show important differences in the chemical shifts of the hydroxyl groups with excellent resolution in the region of 14-15 ppm. The facile identification and quantification of hypericin and its derivative compound pseudohypericin was achieved, without prior HPLC separation, for two H. perforatum extracts from Greek cultivars and two commercial extracts: a dietary supplement, and an antidepressant medicine. The results were compared with those obtained from UV-vis and LC/MS measurements.
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Skalkos D, Gioti E, Stalikas CD, Meyer H, Papazoglou TG, Filippidis G. Photophysical properties of Hypericum perforatum L. extracts--novel photosensitizers for PDT. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2006; 82:146-51. [PMID: 16388961 DOI: 10.1016/j.jphotobiol.2005.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 08/22/2005] [Accepted: 11/01/2005] [Indexed: 11/29/2022]
Abstract
We report the preparation of the methanolic extract (ME), and polar methanolic fraction (PMF) from the plant Hypericum perforatum L. The extracts contain various photosensitizing constituents such as naphthodianthrone derivatives (in 1.37% w/w), and chlorophylls (in 0.08% w/w). Upon light emission these constituents can be activated, providing photodynamic properties to the extracts, and making them a potent, new class, natural photosensitizers for use in photodynamic therapy (PDT), and photodynamic diagnosis (PDD). The absorbance spectra of the extracts are similar to the spectrum of hypericin, the main naphthodianthrone identified within, with two major bands at 548 and 590 nm. The fluorescence spectra in ethanol exhibit two main bands around 595 and 640 nm, in accordance with the spectrum of pure hypericin. The fluorescence intensity of PMF at 595 nm is only eight times less than the intensity of pure hypericin at the same wavelength, even though its hypericin concentration is only 0.57% w/w. The dependence of the PMF fluorescence signal on the pH of the medium, alone and in comparison with the signal of hypericin, has been investigated. PMF signal fades steadily, and smoothly both in acidic, and basic environment.
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Affiliation(s)
- D Skalkos
- Department of Materials Science and Engineering, University of Ioannina, Ioannina GR-45110, Greece.
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Shen L, Ji HF, Zhang HY. Anion of hypericin is crucial to understanding the photosensitive features of the pigment. Bioorg Med Chem Lett 2005; 16:1414-7. [PMID: 16337376 DOI: 10.1016/j.bmcl.2005.11.056] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Revised: 10/26/2005] [Accepted: 11/10/2005] [Indexed: 11/17/2022]
Abstract
Photosensitive behaviors of hypericin (HYP) have attracted much attention, because of HYP's great potential in photodynamic therapy. It has been found that HYP differs from homologous pigments, such as hypocrellin A (HA), in photosensitive features. For instance, despite the comparable triplet state quantum yields, HYP holds a much lower singlet oxygen yield than HA. To understand the unique photosensitive behaviors of HYP, time-dependent density functional theory is employed to calculate a series of excited-state properties of HYP and its anion (dominant in polar solvents), which are then compared with excited-state properties of HA. It is revealed that the stronger electron-donating power of HYP anion than that of HA is responsible for the HYP's photosensitive features.
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Affiliation(s)
- Liang Shen
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Center for Advanced Study, Shandong University of Technology, Zibo 255049, PR China
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Kapsokalyvas D, Dimitriou H, Skalkos D, Konstantoudakis G, Filippidis G, Stiakaki E, Papazoglou T, Kalmanti M. Does Hypericum perforatum L. extract show any specificity as photosensitizer for HL-60 leukemic cells and cord blood hemopoietic progenitors during photodynamic therapy? JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2005; 80:208-16. [PMID: 15979884 DOI: 10.1016/j.jphotobiol.2005.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Accepted: 04/21/2005] [Indexed: 01/22/2023]
Abstract
UNLABELLED Autologous bone marrow transplantation is a therapeutic modality that increases the survival rates for children with malignancies with poor prognosis but relapse rates are high and attributed partially to the existence of residual malignant cells. Photodynamic treatment (PDT) has been developed among purging strategies. We investigated the effect of the methanolic extract (ME) and its polar methanolic fraction (PMF) of Hypericum perforatum L., as a new photosensitizer for the leukemic cell line HL-60 and cord blood (CB) hemopoietic progenitors as well as the subcellular localization of the photosensitizer. METHODS ME and PMF were prepared after extraction of the dry herb with methanol (ME), followed by liquid-liquid extraction with petroleum ether (PMF). Cells were incubated with the extracts before irradiation with Nd-Yvo Laser. Various concentrations of PMF or ME as well as irradiation doses were tested. Following irradiation, cell viability was determined by trypan blue in continuous liquid cultures for HL-60 cells and in clonogenic assays for CB cells. The subcellular localization of the photosensitizer was determined by confocal microscopy. RESULTS Laser photoirradiation in the presence of both PMF and ME induces the killing of HL-60 cells. This effect is dose dependent. No CFU-GM and BFU-E growth was observed from CB mononuclear cells under the tested experimental conditions. Confocal microscopy revealed that the extracts localize mainly in the cytoplasm of the cells. CONCLUSIONS PDT with both PMF and ME induces the killing of HL-60 leukemic cells and the optimal conditions of treatment were determined. This effect of PDT/PMF was also exerted on CB progenitor cells indicative of the non-selective uptake of the photosensitizer by malignant cells. Though this suggests that PDT/PMF cannot be helpful in autologous bone marrow purging, these novel extracts can however be beneficial in the PDT treatment of tumors given their photostability, low toxicity and low cost.
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Affiliation(s)
- D Kapsokalyvas
- Department of Pediatric Hematology/Oncology, University of Crete, Medical School, P.O. Box 2208, 71003 Heraklion Crete, Greece.
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Crnolatac I, Huygens A, van Aerschot A, Busson R, Rozenski J, de Witte PAM. Synthesis, in vitro cellular uptake and photo-induced antiproliferative effects of lipophilic hypericin acid derivatives. Bioorg Med Chem 2005; 13:6347-53. [PMID: 16213734 DOI: 10.1016/j.bmc.2005.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 04/19/2005] [Accepted: 05/25/2005] [Indexed: 10/25/2022]
Abstract
Hypericin, a naturally occurring hydroxylated phenanthroperylene dione, is used as a powerful photosensitizer for photodynamic therapy as well as a diagnostic tool for the fluorescence detection of flat neoplastic lesions in the bladder of patients. Both applications are based on the tumouritropic characteristics of the compound. To get more insight into some of the physicochemical properties of hypericin affecting its tumouritropic characteristics, we set out to synthesize a series of more lipophilic hypericins. For this purpose, a synthetic pathway to hypericin acid amides with hydrocarbon chains of different lengths stably attached by an amide bond at position C10 was explored. Hypericin acid proved inert in amide forming reactions, whereas the precursor protohypericin acid showed higher reactivity and resulted in the desired amide derivatives, which afterwards can be easily converted into their phenanthroperylene dione form. Hexyl-, octyl-, decyl- and dodecylamides of hypericin acid were successfully synthesized in this way. In vitro cellular uptake and photo-induced antiproliferative effects of the compounds were evaluated, using the human moderately differentiated non-invasive papillary transitional carcinoma RT-112 cell line. Whereas the more lipophilic amides were taken up limitedly, the hexylamide accumulated approx. as well as hypericin itself. From the antiproliferative data it can further be concluded that not only the cellular uptake, but also the light-induced activity, is affected by the introduced structural changes.
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Affiliation(s)
- Ivo Crnolatac
- Laboratorium voor Farmaceutische Biologie en Fytofarmacologie, Faculteit Farmaceutische Wetenschappen, Katholieke Universiteit Leuven, Belgium
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Plaza P, Mahet M, Tchaikovskaya ON, Martin MM. Excitation energy effect on the early photophysics of hypericin in solution. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Huygens A, Kamuhabwa AR, de Witte PAM. Stability of different formulations and ion pairs of hypericin. Eur J Pharm Biopharm 2005; 59:461-8. [PMID: 15760726 DOI: 10.1016/j.ejpb.2004.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 09/01/2004] [Accepted: 09/01/2004] [Indexed: 10/25/2022]
Abstract
Hypericin, solubilized in an instillation fluid consisting of an aqueous buffer supplemented with 1% plasma proteins, is currently used as a clinical diagnostic tool for the detection of superficial TCC (transitional cell carcinoma) tumors. However, the development of a sterile and stable hypericin stock formulation, excluding the presence of plasma constituents, would be an important factor in a more general clinical application of the method. Therefore, we investigated the stability of several heat sterilized hypericin formulations and ion pairs. Besides sodium hypericinate (in distilled water, in phosphate buffer, in polyethyleneglycol (PEG) 400), several other hypericinate salts (potassium, lysine, TRIS or hexylamine) were investigated. As to that, the physical appearance of different hypericin concentrates stored at 4 and 37 degrees C was investigated. Besides, after dilution into cell culture medium, the ability of hypericin remaining to accumulate in tumor cells and demonstrating photocytotoxic effects upon light irradiation was assessed. These findings suggest that PEG 400 is an excellent hypericin formulation, since it maintained the stability of the compound for at least 120 d when stored at either 4 or 37 degrees C. PEG 400 therefore is a suitable vehicle for the storage of hypericin prior to preparation of the bladder instillation solution.
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Affiliation(s)
- Ann Huygens
- Laboratorium voor Farmaceutische Biologie en Fytofarmacologie, Faculteit Farmaceutische Wetenschappen, Katholieke Universiteit Leuven, Leuven, Belgium
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Huygens A, Kamuhabwa AR, van Cleynenbreugel B, van Poppel H, Roskams T, de Witte PAM. In vivo accumulation of different hypericin ion pairs in the urothelium of the rat bladder. BJU Int 2005; 95:436-41. [PMID: 15679810 DOI: 10.1111/j.1464-410x.2005.05316.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To optimise the diagnostic and phototherapeutic efficacy of hypericin in superficial bladder cancer, by developing a bladder instillation fluid that does not depend on the presence of plasma proteins for an appropriate and reliable urothelial uptake of hypericin. MATERIALS AND METHODS Sodium hypericinate (in distilled water, in sodium phosphate buffer, or in polyethylene glycol) and several other hypericinate salts (potassium, lysine, TRIS or hexylamine) were instilled with no plasma constituents into the rat bladder. The accumulation of hypericin was assessed with fluorescence microscopy. RESULTS The diagnostic and phototherapeutic efficacy of hypericin depends on its ability to penetrate the tumour lesions sufficiently to show a fluorescent signal or elicit a photodynamic response. Several instillation fluids meet the purpose, as the urothelial accumulation of hypericin was similar to that obtained with the instillation fluid supplemented with plasma proteins, used in clinical practice. The highest concentrations of hypericin in the urothelium of the rat bladder were obtained with hypericin instillation solutions prepared with distilled water or 20% polyethylene glycol 400 in distilled water. Fluorescence microscopy showed that hypericin was selectively localized in the urothelium. Furthermore, all variables investigated (hydrophilic/lipophilic balance, pH, saline, presence of organic solvent) can dramatically influence the in vivo accumulation of hypericin. CONCLUSION An appropriate and reliable urothelial uptake of hypericin does not depend on the presence of plasma protein supplements in the bladder instillation fluid.
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Affiliation(s)
- Ann Huygens
- Laboratory Pharmaceutical Biology and Phytopharmacology, Faculty of Pharmaceutical Science, UZ Gasthuisberg, KU Leuven, Van Evenstraat 4, B-3000 Leuven, Belgium
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