Application of Quantum Chemical Calculation of Nuclear Magnetic Resonance Parameters in the Structure Elucidation of Natural Products

doi:10.11938/cjmr20182682

Abstract

Abstract: With the continuous development of quantum chemical theories and advances in computer hardware and software, the methods for quantum chemical calculation of nuclear magnetic resonance parameters (qcc-NMR) are improved significantly in the past decade. With these methods, accurate calculated results can often be obtained at a relatively low cost. Furthermore, the methods for result analysis have been advanced from simple statistical parameters to more sophisticated procedures based on more complicated statistical methods or artificial neuron networks, etc. These advances make qcc-NMR a significant complement to traditional spectrometric methods, and more and more useful in natural product research. In this paper, the application of qcc-NMR in natural product research is reviewed. Representative researches featuring the use of qcc-NMR are highlighted.

Key words: quantum chemical calculation, nuclear magnetic resonance (NMR) parameters, natural product, structure elucidation, DP4 probability analysis

CLC Number:

O482.53

HU Kun, SUN Han-dong, PUNO Pema-tenzin. Application of Quantum Chemical Calculation of Nuclear Magnetic Resonance Parameters in the Structure Elucidation of Natural Products[J]. Chinese Journal of Magnetic Resonance, 2019, 36(3): 359-376.

References

[1] NEWMAN D J, CRAGG G M. Natural products as sources of new drugs from 1981 to 2014[J]. J Nat Prod, 2016, 79(3):629-661.
[2] BRETON R C, REYNOLDS W F. Using NMR to identify and characterize natural products[J]. Nat Prod Rep, 2013, 30(4):501-524.
[3] WANG B, LIU X, ZHU G L, et al. Applications of new two-dimensional NMR spectroscopy in natural products research[J]. Chinese J Magn Reson, 2013, 30(4):602-613. 王蓓, 刘星, 朱国磊, 等. 新二维核磁共振谱在天然产物研究中的应用[J]. 波谱学杂志, 2013, 30(4):602-613.
[4] REYNOLDS W F. Natural product structure elucidation by NMR spectroscopy[M]//BADAL S, DELGODA R. Pharmacognosy. Boston:Academic Press, 2017:567-596.
[5] SUN L J, HU X F, C X, et al. NMR characterization of flavanone naringenin 7-O-glycoside diastereomer[J]. Chinese J Magn Reson, 2017, 34(4):465-473. 孙丽娟, 胡小芳, 程寻, 等. 柚皮素7-O-葡萄糖苷非对映异构体的NMR波谱分析[J]. 波谱学杂志, 2017, 34(4):465-473.
[6] YIN T P, CHEN Y, LUO P, et al. Structural elucidation and NMR spectral assignments of two C₁₉-diterpenoid alkaloids[J]. Chinese J Magn Reson, 2018, 35(1):90-97. 尹田鹏, 陈阳, 罗萍, 等. 两个C₁₉-二萜生物碱的结构鉴定和NMR信号归属[J]. 波谱学杂志, 2018, 35(1):90-97.
[7] HALABALAKI M, VOUGOGIANNOPOULOU K, MIKROS E, et al. Recent advances and new strategies in the NMR-based identification of natural products[J]. Curr Opin in Biotech, 2014, 25:1-7.
[8] MENNA M, IMPERATORE C, MANGONI A, et al. Challenges in the configuration assignment of natural products. A case-selective perspective[J]. Nat Prod Rep, 2019, 36(3):476-489.
[9] NICOLAOU K C, SNYDER S A. Chasing molecules that were never there:misassigned natural products and the role of chemical synthesis in modern structure elucidation[J]. Angew Chem Int Ed, 2005, 44(7):1012-1044.
[10] SUYAMA T L, GERWICK W H, MCPHAIL K L. Survey of marine natural product structure revisions:A synergy of spectroscopy and chemical synthesis[J]. Bioorg Med Chem, 2011, 19(22):6675-6701.
[11] YOO H D, NAM S J, CHIN Y W, et al. Misassigned natural products and their revised structures[J]. Arch Pharm Res, 2016, 39(2):143-153.
[12] CHHETRI B K, LAVOIE S, SWEENEY-JONES A M, et al. Recent trends in the structural revision of natural products[J]. Nat Prod Rep, 2018, 35(6):514-531.
[13] BARONE G, DUCA D, SILVESTRI A, et al. Determination of the relative stereochemistry of flexible organic compounds by ab initio methods:conformational analysis and Boltzmann-averaged GIAO ¹³C NMR chemical shifts[J]. Chem-Eur J, 2002, 8(14):3240-3245.
[14] BARONE G, GOMEZ-PALOMA L, DUCA D, et al. Structure validation of natural products by quantum-mechanical GIAO calculations of ¹³C NMR chemical shifts[J]. Chem-Eur J, 2002, 8(14):3233-3239.
[15] GRIMBLAT N, SAROTTI A M. Computational chemistry to the rescue:modern toolboxes for the assignment of complex molecules by GIAO NMR calculations[J]. Chem-Eur J, 2016, 22(35):12246-12261.
[16] BIFULCO G, DAMBRUOSO P, GOMEZ-PALOMA L, et al. Determination of relative configuration in organic compounds by NMR spectroscopy and computational methods[J]. Chem Rev, 2007, 107(9):3744-3779.
[17] DI MICCO S, CHINI M G, RICCIO R, et al. Quantum mechanical calculation of NMR parameters in the stereostructural determination of natural products[J]. Eur J Org Chem, 2010, 2010(8):1411-1434.
[18] LODEWYK M W, SIEBERT M R, TANTILLO D J. Computational prediction of ¹H and ¹³C chemical shifts:a useful tool for natural product, mechanistic, and synthetic organic chemistry[J]. Chem Rev, 2012, 112(3):1839-1862.
[19] BAGNO A, SAIELLI G. Addressing the stereochemistry of complex organic molecules by density functional theory-NMR[J]. Wires Comput Mol Sci, 2015, 5(2):228-240.
[20] GU B B, LIN H W. Quantum chemical calculation of ¹H and ¹³C chemical shifts and ¹H-¹H coupling constants in structure assignment of natural products[J]. Journal of International Pharmaceutical Research, 2015, 42(6):706-712. 顾斌斌, 林厚文. 量子化学计算¹H和¹³C化学位移与¹H-¹H偶合常数在天然产物结构鉴定中的运用[J]. 国际药学研究杂志, 2015, 42(6):706-712.
[21] NAVARRO-VAZQUEZ A. State of the art and perspectives in the application of quantum chemical prediction of ¹H and ¹³C chemical shifts and scalar couplings for structural elucidation of organic compounds[J]. Magn Reson Chem, 2017, 55(1):29-32.
[22] TANG Y, XUE Y, DU G, et al. Structural revisions of a class of natural products:scaffolds of aglycon analogues of fusicoccins and cotylenins isolated from fungi[J]. Angew Chem Int Ed, 2016, 55(12):4069-4073.
[23] SAROTTI A M. Structural revision of two unusual rhamnofolane diterpenes, curcusones I and J, by means of DFT calculations of NMR shifts and coupling constants[J]. Org Biomol Chem, 2018, 16(6):944-950.
[24] GRIMBLAT N, ZANARDI M M, SAROTTI A M. Beyond DP4:an improved probability for the stereochemical assignment of isomeric compounds using quantum chemical calculations of NMR shifts[J]. J Org Chem, 2015, 80(24):12526-12534.
[25] SECO J M, QUINOA E, RIGUERA R. Assignment of the absolute configuration of polyfunctional compounds by NMR using chiral derivatizing agents[J]. Chem Rev, 2012, 112(8):4603-4641.
[26] ZANARDI M M, BIGLIONE F A, SORTINO M A, et al. General quantum-based NMR method for the assignment of absolute configuration by single or double derivatization:Scope and limitations[J]. J Org Chem, 2018, 83(19):11839-11849.
[27] SHI Y M, CAI S L, LI X N, et al. LC-UV-guided isolation and structure determination of lancolide E:a nortriterpenoid with a tetracyclo[5.4.0.02,4.03,7] undecane-bridged system from a "talented" schisandra plant[J]. Org Lett, 2016, 18(1):100-103.
[28] WILLOUGHBY P H, JANSMA M J, HOYE T R. A guide to small-molecule structure assignment through computation of ¹H and ¹³C NMR chemical shifts[J]. Nat Protoc, 2014, 9(3):643-660.
[29] FRISCH M J, TRUCKS G W, SCHLEGEL H B, et al. Gaussian 16 Rev. B.01[CP]. Wallingford, CT:2016.
[30] NEESE F. Software update:the ORCA program system, version 4.0[J]. Wires Comput Mol Sci, 2018, 8(1):e1327.
[31] AIDAS K, ANGELI C, BAK K L, et al. The Dalton quantum chemistry program system[J]. Wires Comput Mol Sci, 2014, 4(3):269-284.
[32] HAWKINS P C D. Conformation generation:the state of the art[J]. J Chem Inf Model, 2017, 57(8):1747-1756.
[33] VAINIO M J, JOHNSON M S. Generating conformer ensembles using a multiobjective genetic algorithm[J]. J Chem Inf Model, 2007, 47(6):2462-2474.
[34] MITEVA M A, GUYON F, TUFFéRY P. Frog2:Efficient 3D conformation ensemble generator for small compounds[J]. Nucleic Acids Res, 2010, 38(Web Server issue):W622-W627.
[35] CASE D A, CHEATHAM T E, DARDEN T, et al. The Amber biomolecular simulation programs[J]. J Comput Chem, 2005, 26(16):1668-1688.
[36] SPOEL D V D, LINDAHL E, HESS B, et al. GROMACS:fast, flexible, and free[J]. J Comput Chem, 2005, 26(16):1701-1718.
[37] GRIMME S, BANNWARTH C, SHUSHKOV P. A robust and accurate tight-binding quantum chemical method for structures, vibrational frequencies, and noncovalent interactions of large molecular systems parametrized for all spd-block elements (Z=1-86)[J]. J Chem Theory Comput, 2017, 13(5):1989-2009.
[38] HALGREN T A. Merck molecular force field. I. Basis, form, scope, parameterization, and performance of MMFF94[J]. J Comput Chem, 1996, 17(5,6):490-519.
[39] BANKS J L, BEARD H S, CAO Y, et al. Integrated modeling program, applied chemical theory (IMPACT)[J]. J Comput Chem, 2005, 26(16):1752-1780.
[40] STEWART J J P. Optimization of parameters for semiempirical methods V:Modification of NDDO approximations and application to 70 elements[J]. J Mol Model, 2007, 13(12):1173-1213.
[41] STEPHENS P J, DEVLIN F J, CHABALOWSKI C F, et al. Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields[J]. J Phys Chem, 1994, 98(45):11623-11627.
[42] ZHAO Y, TRUHLAR D G. The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements:two new functionals and systematic testing of four M06-class functionals and 12 other functionals[J]. Theor Chem Acc, 2008, 120(1):215-241.
[43] CHAI J D, HEAD-GORDON M. Long-range corrected hybrid density functionals with damped atom-atom dispersion corrections[J]. PCCP, 2008, 10(44):6615-6620.
[44] GRIMME S, ANTONY J, EHRLICH S, et al. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu[J]. J Chem Phys, 2010, 132(15):154104.
[45] RASSOLOV V A, RATNER M A, POPLE J A, et al. 6-31G* basis set for third-row atoms[J]. J Comput Chem, 2001, 22(9):976-984.
[46] KRISHNAN R, BINKLEY J S, SEEGER R, et al. Self-consistent molecular orbital methods. XX. A basis set for correlated wave functions[J]. J Chem Phys, 1980, 72(1):650-654.
[47] SCHäFER A, HORN H, AHLRICHS R. Fully optimized contracted Gaussian basis sets for atoms Li to Kr[J]. J Chem Phys, 1992, 97(4):2571-2577.
[48] SCHäFER A, HUBER C, AHLRICHS R. Fully optimized contracted Gaussian basis sets of triple zeta valence quality for atoms Li to Kr[J]. J Chem Phys, 1994, 100(8):5829-5835.
[49] BUTTS C P, JONES C R, TOWERS E C, et al. Interproton distance determinations by NOE-surprising accuracy and precision in a rigid organic molecule[J]. Org Biomol Chem, 2011, 9(1):177-184.
[50] BUTTS C P, JONES C R, SONG Z, et al. Accurate NOE-distance determination enables the stereochemical assignment of a flexible molecule-arugosin C[J]. Chem Commun, 2012, 48(72):9023-9025.
[51] JONES C R, GREENHALGH M D, BAME J R, et al. Subtle temperature-induced changes in small molecule conformer dynamics-observed and quantified by NOE spectroscopy[J]. Chem Commun, 2016, 52(14):2920-2923.
[52] FACELLI J C. Calculations of chemical shieldings:theory and applications[J]. Concept Magn Reson Part A, 2004, 20A(1):42-69.
[53] DITCHFIELD R. Self-consistent perturbation theory of diamagnetism[J]. Mol Phys, 1974, 27(4):789-807.
[54] KEITH T A, BADER R F W. Calculation of magnetic response properties using a continuous set of gauge transformations[J]. Chem Phys Lett, 1993, 210(1):223-231.
[55] FLAIG D, MAURER M, HANNI M, et al. Benchmarking hydrogen and carbon NMR chemical shifts at HF, DFT, and MP2 levels[J]. J Chem Theory Comput, 2014, 10(2):572-578.
[56] IRON M A. Evaluation of the factors impacting the accuracy of ¹³C NMR chemical shift predictions using density functional theory-the advantage of long-range corrected functionals[J]. J Chem Theory Comput, 2017, 13(11):5798-5819.
[57] WⅡTALA K W, HOYE T R, CRAMER C J. Hybrid density functional methods empirically optimized for the computation of ¹³C and ¹H chemical shifts in chloroform solution[J]. J Chem Theory Comput, 2006, 2(4):1085-1092.
[58] BROWN S G, JANSMA M J, HOYE T R. Case study of empirical and computational chemical shift analyses:reassignment of the relative configuration of phomopsichalasin to that of diaporthichalasin[J]. J Nat Prod, 2012, 75(7):1326-1331.
[59] KEAL T W, TOZER D J. The exchange-correlation potential in Kohn-Sham nuclear magnetic resonance shielding calculations[J]. J Chem Phys, 2003, 119(6):3015-3024.
[60] ADAMO C, BARONE V. Exchange functionals with improved long-range behavior and adiabatic connection methods without adjustable parameters:The mPW and mPW1PW models[J]. J Chem Phys, 1998, 108(2):664-675.
[61] WILSON P J, BRADLEY T J, TOZER D J. Hybrid exchange-correlation functional determined from thermochemical data and ab initio potentials[J]. J Chem Phys, 2001, 115(20):9233-9242.
[62] ADAMO C, BARONE V. Toward reliable density functional methods without adjustable parameters:The PBE0 model[J]. J Chem Phys, 1999, 110(13):6158-6170.
[63] JENSEN F. Basis set convergence of nuclear magnetic shielding constants calculated by density functional methods[J]. J Chem Theory Comput, 2008, 4(5):719-727.
[64] JENSEN F. Unifying general and segmented contracted basis sets. Segmented polarization consistent basis sets[J]. J Chem Theory Comput, 2014, 10(3):1074-1085.
[65] GRIMME S, BANNWARTH C, DOHM S, et al. Fully automated quantum-chemistry-based computation of spin-spin-coupled nuclear magnetic resonance spectra[J]. Angew Chem Int Ed, 2017, 56(46):14763-14769.
[66] XIN D, SADER C A, CHAUDHARY O, et al. Development of a ¹³C NMR chemical shift prediction procedure using B3LYP/cc-pVDZ and empirically derived systematic error correction terms:a computational small molecule structure elucidation method[J]. J Org Chem, 2017, 82(10):5135-5145.
[67] KUTATELADZE A G, REDDY D S. High-throughput in silico structure validation and revision of halogenated natural products Is enabled by parametric corrections to DFT-computed ¹³C NMR chemical shifts and spin-spin coupling constants[J]. J Org Chem, 2017, 82(7):3368-3381.
[68] KUTATELADZE A G, KUZNETSOV D M. Triquinanes and related sesquiterpenes revisited computationally:structure corrections of hirsutanols B and D, hirsutenol E, cucumin B, antrodins C-E, chondroterpenes A and H, chondrosterins C and E, dichrocephone A, and pethybrene[J]. J Org Chem, 2017, 82(20):10795-10802.
[69] STOYCHEV G L, AUER A A, IZSáK R, et al. Self-consistent field calculation of nuclear magnetic resonance chemical shielding constants using Gauge-Including Atomic Orbitals and approximate two-electron integrals[J]. J Chem Theory Comput, 2018, 14(2):619-637.
[70] SAROTTI A M, PELLEGRINET S C. A multi-standard approach for GIAO (13)C NMR calculations[J]. J Org Chem, 2009, 74(19):7254-7260.
[71] SAROTTI A M, PELLEGRINET S C. Application of the multi-standard methodology for calculating ¹H NMR chemical shifts[J]. J Org Chem, 2012, 77(14):6059-6065.
[72] BALLY T, RABLEN P R. Quantum-chemical simulation of ¹H NMR spectra. 2. Comparison of DFT-based procedures for computing proton-proton coupling constants in organic molecules[J]. J Org Chem, 2011, 76(12):4818-4830.
[73] MATSUMORI N, KANENO D, MURATA M, et al. Stereochemical determination of acyclic structures based on carbon-proton spin-coupling constants. A method of configuration analysis for natural products[J]. J Org Chem, 1999, 64(3):866-876.
[74] KUTATELADZE A G, MUKHINA O A. Relativistic force field:parametric computations of proton-proton coupling constants in ¹H NMR spectra[J]. J Org Chem, 2014, 79(17):8397-8406.
[75] KUTATELADZE A G, MUKHINA O A. Relativistic force field:parametrization of ¹³C-¹H nuclear spin-spin coupling constants[J]. J Org Chem, 2015, 80(21):10838-10848.
[76] BIFULCO G, BASSARELLO C, RICCIO R, et al. Quantum mechanical calculations of NMR J coupling values in the determination of relative configuration in organic compounds[J]. Org Lett, 2004, 6(6):1025-1028.
[77] JENSEN F. The optimum contraction of basis sets for calculating spin-spin coupling constants[J]. Theor Chem Acc, 2010, 126(5):371-382.
[78] SMITH S G, GOODMAN J M. Assigning the stereochemistry of pairs of diastereoisomers using GIAO NMR shift calculation[J]. J Org Chem, 2009, 74(12):4597-4607.
[79] SMITH S G, GOODMAN J M. Assigning stereochemistry to single diastereoisomers by GIAO NMR calculation:the DP4 probability[J]. J Am Chem Soc, 2010, 132(37):12946-12959.
[80] XIN D, JONES P J, GONNELLA N C. DiCE:diastereomeric in silico chiral elucidation, expanded DP4 probability theory method for diastereomer and structural assignment[J]. J Org Chem, 2018, 83(9):5035-5043.
[81] ERMANIS K, PARKES K E, AGBACK T, et al. Expanding DP4:application to drug compounds and automation[J]. Org Biomol Chem, 2016, 14(16):3943-3949.
[82] ERMANIS K, PARKES K E B, AGBACK T, et al. Doubling the power of DP4 for computational structure elucidation[J]. Org Biomol Chem, 2017, 15(42):8998-9007.
[83] SAROTTI A M. Successful combination of computationally inexpensive GIAO ¹³C NMR calculations and artificial neural network pattern recognition:a new strategy for simple and rapid detection of structural misassignments[J]. Org Biomol Chem, 2013, 11(29):4847-4859.
[84] ZANARDI M M, SAROTTI A M. GIAO C-H COSY simulations merged with artificial neural networks pattern recognition analysis. Pushing the structural validation a step forward[J]. J Org Chem, 2015, 80(19):9371-9378.
[85] KIM C S, SUBEDI L, OH J, et al. Bioactive triterpenoids from the twigs of Chaenomeles sinensis[J]. J Nat Prod, 2017, 80(4):1134-1140.
[86] ZANARDI M M, SUáREZ A G, SAROTTI A M. Determination of the relative configuration of terminal and spiroepoxides by computational methods. Advantages of the inclusion of unscaled data[J]. J Org Chem, 2017, 82(4):1873-1879.
[87] XIN D, SADER C A, FISCHER U, et al. Systematic investigation of DFT-GIAO 15N NMR chemical shift prediction using B3LYP/cc-pVDZ:application to studies of regioisomers, tautomers, protonation states and N-oxides[J]. Org Biomol Chem, 2017, 15(4):928-936.
[88] TRIPATHI A, SCHOFIELD M M, CHLIPALA G E, et al. Baulamycins A and B, broad-spectrum antibiotics identified as inhibitors of siderophore biosynthesis in Staphylococcus aureus and Bacillus anthracis[J]. J Am Chem Soc, 2014, 136(4):1579-1586.
[89] GUCHHAIT S, CHATTERJEE S, AMPAPATHI R S, et al. Total synthesis of reported structure of baulamycin A and Its congeners[J]. J Org Chem, 2017, 82(5):2414-2435.
[90] WU J, LORENZO P, ZHONG S, et al. Synergy of synthesis, computation and NMR reveals correct baulamycin structures[J]. Nature, 2017, 547(7664):436-440.
[91] XIAO W L, YANG L M, GONG N B, et al. Rubriflordilactones A and B, two novel bisnortriterpenoids from Schisandra rubriflora and their biological activities[J]. Org Lett, 2006, 8(5):991-994.
[92] YANG P, YAO M, LI J, et al. Total synthesis of rubriflordilactone B[J]. Angew Chem Int Ed, 2016, 55(24):6964-6968.
[93] GRIMBLAT N, KAUFMAN T S, SAROTTI A M. Computational chemistry driven solution to rubriflordilactone B[J]. Org Lett, 2016, 18(24):6420-6423.
[94] KUTATELADZE A G. Structure revision of decurrensides A-E enabled by the RFF parametric calculations of proton spin-spin coupling constants[J]. J Org Chem, 2016, 81(18):8659-8661.
[95] REDDY D S, KUTATELADZE A G. Structure revision of an acorane sesquiterpene cordycepol A[J]. Org Lett, 2016, 18(19):4860-4863.
[96] CHACON MORALES P A, AMARO-LUIS J M, KUTATELADZE A G. Structure determination and mechanism of formation of a seco-moreliane derivative supported by computational analysis[J]. J Nat Prod, 2017, 80(4):1210-1214.
[97] GU B B, TANG J, WANG S P, et al. Structure, absolute configuration, and variable-temperature 1H-NMR study of (±)-versiorcinols A-C, three racemates of diorcinol monoethers from the sponge-associated fungus Aspergillus versicolor 16F-11[J]. RSC Adv, 2017, 7(79):50254-50263.
[98] SUN C P, KUTATELADZE A G, ZHAO F, et al. A novel withanolide with an unprecedented carbon skeleton from physalis angulata[J]. Org Biomol Chem, 2017, 15(5):1110-1114.
[99] WANG C, HUO X K, LUAN Z L, et al. Alismanin A, a triterpenoid with a C34 skeleton from Alisma orientale as a natural agonist of human pregnane X receptor[J]. Org Lett, 2017, 19(20):5645-5648.
[100] KUTATELADZE A G, KUZNETSOV D M, BELOGLAZKINA A A, et al. Addressing the challenges of structure elucidation in natural products possessing the oxirane moiety[J]. J Org Chem, 2018, 83(15):8341-8352.
[101] BISSON J, SIMMLER C, CHEN S N, et al. Dissemination of original NMR data enhances reproducibility and integrity in chemical research[J]. Nat Prod Rep, 2016, 33(9):1028-1033.
[102] MCALPINE J B, CHEN S N, KUTATELADZE A, et al. The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research[J]. Nat Prod Rep, 2019, 36(1):35-107.
[103] SREBRO-HOOPER M, AUTSCHBACH J. Calculating natural optical activity of molecules from first principles[J]. Annu Rev of Phys Chem, 2017, 68(1):399-420.
[104] PESCITELLI G, DI BARI L, BEROVA N. Application of electronic circular dichroism in the study of supramolecular systems[J]. Chem Soc Rev, 2014, 43(15):5211-5233.
[105] STEFANO S, PATRIZIA S, MARCIN G, et al. Absolute configuration determination by quantum mechanical calculation of chiroptical spectra:basics and applications to fungal metabolites[J]. Curr Med Chem, 2018, 25(2):287-320.
[106] POLAVARAPU P L. Molecular structure determination using chiroptical spectroscopy:Where we may go wrong?[J]. Chirality, 2012, 24(11):909-920.
[107] SUAREZ-ORTIZ G A, CERDA-GARCIA-ROJAS C M, FRAGOSO-SERRANO M, et al. Complementarity of DFT calculations, NMR Anisotropy, and ECD for the configurational analysis of brevipolides K-O from Hyptis brevipes[J]. J Nat Prod, 2017, 80(1):181-189.
[108] BUEVICH A V, ELYASHBERG M E. Synergistic combination of CASE algorithms and DFT chemical shift predictions:a powerful approach for structure elucidation, verification, and revision[J]. J Nat Prod, 2016, 79(12):3105-3116.
[109] TANTILLO D J. Walking in the woods with quantum chemistry-applications of quantum chemical calculations in natural products research[J]. Nat Prod Rep, 2013, 30(8):1079-1086.
[110] LIU Y, SAURí J, MEVERS E, et al. Unequivocal determination of complex molecular structures using anisotropic NMR measurements[J]. Science, 2017, 356(6333).
[111] NAVARRO-VáZQUEZ A, GIL R R, BLINOV K. Computer-assisted 3D structure elucidation (CASE-3D) of natural products combining isotropic and anisotropic NMR parameters[J]. J Nat Prod, 2018, 81(1):203-210.
[112] LI G W, LIU H, QIU F, et al. Residual dipolar couplings in structure determination of natural products[J]. Nat Prod Bioprospect, 2018, 8(4):279-295.
[113] INOKUMA Y, YOSHIOKA S, ARIYOSHI J, et al. X-ray analysis on the nanogram to microgram scale using porous complexes[J]. Nature, 2013, 495461.
[114] MATSUDA Y, MITSUHASHI T, LEE S, et al. Astellifadiene:structure determination by NMR spectroscopy and crystalline sponge method, and elucidation of its niosynthesis[J]. Angew Chem Int Ed, 2016, 55(19):5785-5788.
[115] WADA N, KERSTEN ROLAND D, IWAI T, et al. Crystalline-sponge-based structural analysis of crude natural product extracts[J]. Angew Chem, Int Ed, 2018, 130(14):3733-3737.
[116] MEVERS E, SAURí J, LIU Y, et al. Homodimericin A:a complex hexacyclic fungal metabolite[J]. J Am Chem Soc, 2016, 138(38):12324-12327.
[117] MILANOWSKI D J, OKU N, CARTNER L K, et al. Unequivocal determination of caulamidines A and B:application and validation of new tools in the structure elucidation tool box[J]. Chem Sci, 2018, 9(2):307-314.