CoChat
Sign Up
Cited by 48melanin and skin pigmentationMicrobial Metabolism and ApplicationsCultural Heritage Materials Analysis

Isolation and characterization of allomelanin from pathogenic black knot fungus-a sustainable source of melanin

Open access
Singla, Saranshu, Htut, K. Zin, Zhu, Runyao, Davis, Amara, Ma, Jiayang, Ni, Qing Zhe, Burkart, Michael D., Maurer, Christopher +2 more·2021·ACS Omega
DOI 10.1021/acsomega.1c05030PMC PMC8717558
Open this paper in CoChat — free account

Abstract

High Resolution Image Download MS PowerPoint Slide Melanin, a widespread pigment found in many taxa, is widely recognized for its high refractive index, ultraviolet (UV) protection, radical quenching ability, metal binding, and many other unique properties. The aforementioned characteristic traits make melanin a potential candidate for biomedical, separation, structural coloration, and space applications. However, the commercially available natural (sepia) and synthetic melanin are very expensive, limiting their use in various applications. Additionally, eumelanin has been the primary focus in most of these studies. In the present study, we demonstrate that melanin can be extracted from the pathogenic black knot fungus Apiosporina morbosa with a yield of ∼10% using the acid–base extraction method. The extracted melanin shows irregular morphology. Chemical characterization using X-ray photoelectron spectroscopy, infrared spectroscopy, and solid-state nuclear magnetic resonance spectroscopy reveals that the melanin derived from black knots is the less explored nitrogen-free allomelanin. Additionally, the extracted melanin shows broadband UV absorption typical of other types of melanin. Because of the wide availability and low cost of black knots and the invasive nature of the fungus, black knots can serve as an alternative green source for obtaining allomelanin at a low cost, which could stimulate its use as an UV light absorber and antioxidant in cosmetics and packaging industries.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1021/acsomega.1c05030

Cites

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

No references could be resolved yet.

Research works printed but not linked: 63

  1. Bell A. A.; Wheeler M. H. Biosynthesis and Functions of Fungal Melanins. Annu. Rev. Phytopathol. 1986, 24, 411– 451. 10.1146/annurev.py.24.090186.002211. · DOI · Paper page
  2. Rakoczy L.; Panz T. Melanin Revealed in Spores of the True Slime Moulds Using the Electron Spin Resonance Method. Acta Protozool. 1994, 33, 227– 231.
  3. Pionka P. M.; Rakoczy L. The Electron Paramagnetic Resonance Signals of the Acellular Slime Mould Physarum Nudum Plasmodia Irradiated With White Light. Curr. Top. Biophys. 1997, 21, 83– 86.
  4. Butler M. J.; Day A. W. Fungal Melanins: A Review. Can. J. Microbiol. 1998, 44, 1115– 1136. 10.1139/w98-119. · DOI
  5. Loganathan P.; Kalyanasundaram I. The Melanin of the Myxomycete Stemonitis herbatica. Acta Protozool. 1999, 38, 97– 103.
  6. Liu Y.; Simon J. D. The Effect of Preparation Procedures on the Morphology of Melanin From the Ink Sac of Sepia officinalis. Pigm. Cell Res. 2003, 16, 72– 80. 10.1034/j.1600-0749.2003.00009.x. 12519128 · DOI
  7. Liu Y.; Simon J. D. Isolation and Biophysical Studies of Natural Eumelanins: Applications of Imaging Technologies and Ultrafast Spectroscopy. Pigm. Cell Res. 2003, 16, 606– 618. 10.1046/j.1600-0749.2003.00098.x. 14629718 · DOI
  8. Langfelder K.; Streibel M.; Jahn B.; Haase G.; Brakhage A. A. Biosynthesis of Fungal Melanins and Their Importance for Human Pathogenic Fungi. Fungal Genet. Biol. 2003, 38, 143– 158. 10.1016/s1087-1845(02)00526-1. 12620252 · DOI · Paper page
  9. Krzywda A.; Petelenz E.; Michalczyk D.; Płonka P. M. Sclerotia of the Acellular (True) Slime Mould Fuligo septica as a Model to Study Melanization and Anabiosis. Cell. Mol. Biol. Lett. 2008, 13, 130– 143. 10.2478/s11658-007-0047-5. 17965965 PMC6275577 · DOI
  10. Magarelli M.; Passamonti P.; Renieri C. Purification, Characterization and Analysis of Sepia Melanin From Commercial Sepia Ink (Sepia Officinalis). J. Vet. Med. Zootech. 2010, 5, 18– 28.
  11. Nosanchuk J. D.; Stark R. E.; Casadevall A. Fungal Melanin: What do we Know About Structure?. Front. Microbiol. 2015, 6, 1463 10.3389/fmicb.2015.01463. 26733993 PMC4687393 · DOI · Paper page
  12. Varga M.; Berkesi O.; Darula Z.; May N. V.; Palágyi A. Structural Characterization of Allomelanin From Black Oat. Phytochemistry 2016, 130, 313– 320. 10.1016/j.phytochem.2016.07.002. 27427433 · DOI
  13. Cordero R. J. B.; Casadevall A. Functions of Fungal Melanin Beyond Virulence. Fungal Biol. Rev. 2017, 31, 99– 112. 10.1016/j.fbr.2016.12.003. 31649746 PMC6812541 · DOI
  14. Xiao M.; Chen W.; Li W.; Zhao J.; Hong Y.; Nishiyama Y.; Miyoshi T.; Shawkey M. D.; Dhinojwala A. Elucidation of the Hierarchical Structure of Natural Eumelanins. J. R. Soc. Interface 2018, 15, 20180045 10.1098/rsif.2018.0045. 29514988 PMC5908538 · DOI
  15. D’Alba L.; Shawkey M. D. Melanosomes: Biogenesis, Properties, and Evolution of an Ancient Organelle. Physiol. Rev. 2019, 99, 1– 19. 10.1152/physrev.00059.2017. 30255724 · DOI
  16. Pralea I.-E.; Moldovan R.-C.; Petrache A.-M.; Ilieş M.; Hegheş S.-C.; Ielciu I.; Nicoară R.; Moldovan M.; Ene M.; Radu M.; et al. From Extraction to Advanced Analytical Methods: The Challenges of Melanin Analysis. Int. J. Mol. Sci. 2019, 20, 3943 10.3390/ijms20163943. PMC6719904 31412656 · DOI
  17. Stavenga D. G.; Leertouwer H. L.; Osorio D. C.; Wilts B. D. High Refractive Index of Melanin in Shiny Occipital Feathers of a Bird of Paradise. Light Sci. Appl. 2015, 4, e243 10.1038/lsa.2015.16. · DOI
  18. Micillo R.; Panzella L.; Iacomino M.; Prampolini G.; Cacelli I.; Ferretti A.; Crescenzi O.; Koike K.; Napolitano A.; d’Ischia M. Eumelanin Broadband Absorption Develops From Aggregation-Modulated Chromophore Interactions Under Structural and Redox Control. Sci. Rep. 2017, 7, 41532 10.1038/srep41532. 28150707 PMC5288692 · DOI
  19. Liu Y.; Ai K.; Ji X.; Askhatova D.; Du R.; Lu L.; Shi J. Comprehensive Insights into the Multi-Antioxidative Mechanisms of Melanin Nanoparticles and Their Application to Protect Brain From Injury in Ischemic Stroke. J. Am. Chem. Soc. 2017, 139, 856– 862. 10.1021/jacs.6b11013. 27997170 PMC5752099 · DOI
  20. Li W.; Wang Z.; Xiao M.; Miyoshi T.; Yang X.; Hu Z.; Liu C.; Chuang S. S. C.; Shawkey M. D.; Gianneschi N. C.; Dhinojwala A. Mechanism of UVA Degradation of Synthetic Eumelanin. Biomacromolecules 2019, 20, 4593– 4601. 10.1021/acs.biomac.9b01433. 31696706 · DOI
  21. Żądło A. C.; Sarna T. Interaction of Iron Ions with Melanin. Acta Biochim. Pol. 2019, 66, 459– 462. 10.18388/abp.2019_2889. 31826048 · DOI
  22. Li W.; Patil A.; Zhou X.; Wang Z.; Xiao M.; Shawkey M. D.; Gianneschi N. C.; Dhinojwala A. Characterization of Broadband Complex Refractive Index of Synthetic Melanin Coatings and their Changes After Ultraviolet Irradiation. Appl. Phys. Lett. 2020, 117, 203701 10.1063/5.0024229. · DOI
  23. Wang Y.; Wang X.; Li T.; Ma P.; Zhang S.; Du M.; Dong W.; Xie Y.; Chen M. Effects of Melanin on Optical Behavior of Polymer: From Natural Pigment to Materials Applications. ACS Appl. Mater. Interfaces 2018, 10, 13100– 13106. 10.1021/acsami.8b02658. 29577714 · DOI
  24. Vahidzadeh E.; Kalra A. P.; Shankar K. Melanin-Based Electronics: From Proton Conductors to Photovoltaics and Beyond. Biosens. Bioelectron. 2018, 122, 127– 139. 10.1016/j.bios.2018.09.026. 30245325 · DOI
  25. Echeverri M.; Patil A.; Xiao M.; Li W.; Shawkey M. D.; Dhinojwala A. Developing Noniridescent Structural Color on Flexible Substrates with High Bending Resistance. ACS Appl. Mater. Interfaces 2019, 11, 21159– 21165. 10.1021/acsami.9b04560. 31094502 · DOI
  26. Shankar S.; Wang L.-F.; Rhim J.-W. Effect of Melanin Nanoparticles on the Mechanical, Water Vapor Barrier, and Antioxidant Properties of Gelatin-Based Films for Food Packaging Application. Food Packag. Shelf Life 2019, 21, 100363 10.1016/j.fpsl.2019.100363. · DOI
  27. Liu Y.; Ai K.; Liu J.; Deng M.; He Y.; Lu L. Dopamine-Melanin Colloidal Nanospheres: An Efficient Near-Infrared Photothermal Therapeutic Agent For In Vivo Cancer Therapy. Adv. Mater. 2013, 25, 1353– 1359. 10.1002/adma.201204683. 23280690 · DOI
  28. Alviano C. S.; Farbiarz S. R.; De Souza W.; Angluster J.; Travassos L. R. Characterization of Fonsecaea pedrosoi Melanin. Microbiology 1991, 137, 837– 844. 10.1099/00221287-137-4-837. 1856679 · DOI
  29. Ravishankar J. P.; Muruganandam V.; Suryanarayanan T. S. Isolation and Characterization of Melanin from a Marine Fungus. Bot. Mar. 1995, 38, 413– 416. 10.1515/botm.1995.38.1-6.413. · DOI
  30. Selvakumar P.; Rajasekar S.; Periasamy K.; Raaman N. Isolation and Characterization of Melanin Pigment from Pleurotus cystidiosus (telomorph of Antromycopsis macrocarpa). World J. Microbiol. Biotechnol. 2008, 24, 2125– 2131. 10.1007/s11274-008-9718-2. · DOI
  31. Schmaler-Ripcke J.; Sugareva V.; Gebhardt P.; Winkler R.; Kniemeyer O.; Heinekamp T.; Brakhage A. A. Production of Pyomelanin, a Second Type of Melanin, via the Tyrosine Degradation Pathway in Aspergillus fumigatus. Appl. Environ. Microbiol. 2009, 75, 493– 503. 10.1128/aem.02077-08. 19028908 PMC2620705 · DOI
  32. Liu Y.; Ai K.; Lu L. Polydopamine and its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields. Chem. Rev. 2014, 114, 5057– 5115. 10.1021/cr400407a. 24517847 · DOI · Paper page
  33. Prados-Rosales R.; Toriola S.; Nakouzi A.; Chatterjee S.; Stark R.; Gerfen G.; Tumpowsky P.; Dadachova E.; Casadevall A. Structural Characterization of Melanin Pigments From Commercial Preparations of the Edible Mushroom Auricularia auricula. J. Agr. Food Chem. 2015, 63, 7326– 7332. 10.1021/acs.jafc.5b02713. 26244793 PMC4862413 · DOI
  34. Ribera J.; Panzarasa G.; Stobbe A.; Osypova A.; Rupper P.; Klose D.; Schwarze F. W. M. R. Scalable Biosynthesis of Melanin by the Basidiomycete Armillaria cepistipes. J. Agric. Food Chem. 2018, 67, 132– 139. 10.1021/acs.jafc.8b05071. 30541276 · DOI
  35. Wang L.-F.; Rhim J.-W. Isolation and Characterization of Melanin From Black Garlic and Sepia Ink. LWT--Food Sci. Technol. 2019, 99, 17– 23. 10.1016/j.lwt.2018.09.033. · DOI
  36. Hou R.; Liu X.; Xiang K.; Chen L.; Wu X.; Lin W.; Zheng M.; Fu J. Characterization of the Physicochemical Properties and Extraction Optimization of Natural Melanin from Inonotus hispidus Mushroom. Food Chem. 2019, 277, 533– 542. 10.1016/j.foodchem.2018.11.002. 30502181 · DOI
  37. Zhou X.; McCallum N. C.; Hu Z.; Cao W.; Gnanasekaran K.; Feng Y.; Stoddart J. F.; Wang Z.; Gianneschi N. C. Artificial Allomelanin Nanoparticles. ACS Nano 2019, 13, 10980– 10990. 10.1021/acsnano.9b02160. 31524373 · DOI
  38. Wang Z.; Tschirhart T.; Schultzhaus Z.; Kelly E. E.; Chen A.; Oh E.; Nag O.; Glaser E. R.; Kim E.; Lloyd P. F. Melanin Produced by the Fast-growing Marine Bacterium Vibrio natriegens Through Heterologous Biosynthesis: Characterization and Application. Appl. Environ. Microbiol. 2020, 86, e02749 10.1128/AEM.02749-19. 31836580 PMC7028964 · DOI
  39. Liu Y.; Kempf V. R.; Brian Nofsinger J.; Weinert E. E.; Rudnicki M.; Wakamatsu K.; Ito S.; Simon J. D. Comparison of the Structural and Physical Properties of Human Hair Eumelanin Following Enzymatic or Acid/Base Extraction. Pigm. Cell Res. 2003, 16, 355– 365. 10.1034/j.1600-0749.2003.00059.x. 12859619 · DOI
  40. Wang Y.; Aisen P.; Casadevall A. Melanin, Melanin ″Ghosts,″ and Melanin Composition in Cryptococcus neoformans. Infect. Immun. 1996, 64, 2420– 2424. 10.1128/iai.64.7.2420-2424.1996. 8698461 PMC174092 · DOI · Paper page
  41. Pacelli C.; Cassaro A.; Maturilli A.; Timperio A. M.; Gevi F.; Cavalazzi B.; Stefan M.; Ghica D.; Onofri S. Multidisciplinary Characterization of Melanin Pigments From the Black Fungus Cryomyces antarcticus. Appl. Microbiol. Biotechnol. 2020, 104, 6385– 6395. 10.1007/s00253-020-10666-0. 32447439 · DOI
  42. Fernando W. G. D.; Zhang J. X.; Chen C. Q.; Remphrey W. R.; Schurko A.; Klassen G. R. Molecular and Morphological Characteristics of Apiosporina morbosa, the Causal Agent of Black Knot in Prunus spp. Can. J. Plant Pathol. 2005, 27, 364– 375. 10.1080/07060660509507234. · DOI
  43. Stewart A. Some Observations on the Anatomy and Other Features of the Black Knot. Am. J. Bot. 1914, 1, 112– 126. 10.1002/j.1537-2197.1914.tb05383.x. · DOI
  44. Wainwright S. H.; Lewis F. H. Developmental Morphology of the Black Knot Pathogen on Plum. Phytopathology 1970, 60, 1238– 1244. 10.1094/phyto-60-1238. · DOI
  45. Smith D. H.; Lewis F. H.; Wainwright S. H. Epidemiology of the Black Knot Disease of Plums. Phytopathology 1970, 60, 1441– 1444. 10.1094/phyto-60-1441. · DOI
  46. Huang Z.; Lui H.; Chen X. K.; Alajlan A.; McLean D. I.; Zeng H. Raman Spectroscopy of In Vivo Cutaneous Melanin. J. Biomed. Opt. 2004, 9, 1198– 1206. 10.1117/1.1805553. 15568940 · DOI
  47. Capozzi V.; Perna G.; Gallone A.; Biagi P. F.; Carmone P.; Fratello A.; Guida G.; Zanna P.; Cicero R. Raman and Optical Spectroscopy of Eumelanin Films. J. Mol. Struct. 2005, 744-747, 717– 721. 10.1016/j.molstruc.2004.11.074. · DOI
  48. Galván I.; Jorge A.; Ito K.; Tabuchi K.; Solano F.; Wakamatsu K. Raman Spectroscopy as a Non-Invasive Technique for the Quantification of Melanins in Feathers and Hairs. Pigm. Cell Melanoma Res. 2013, 26, 917– 923. 10.1111/pcmr.12140. 23890020 · DOI
  49. Culka A.; Jehlička J.; Ascaso C.; Artieda O.; Casero C. M.; Wierzchos J. Raman Microspectrometric Study of Pigments in Melanized Fungi from the Hyperarid Atacama Desert Gypsum Crust. J. Raman Spectrosc. 2017, 48, 1487– 1493. 10.1002/jrs.5137. · DOI
  50. Camacho E.; Vij R.; Chrissian C.; Prados-Rosales R.; Gil D.; O’Meally R. N.; Cordero R. J. B.; Cole R. N.; McCaffery J. M.; Stark R. E.; Casadevall A. The Structural Unit of Melanin in the Cell Wall of the Fungal Pathogen Cryptococcus neoformans. J. Biol. Chem. 2019, 294, 10471– 10489. 10.1074/jbc.ra119.008684. 31118223 PMC6615676 · DOI
  51. Ito S. Reexamination of the Structure of Eumelanin. Biochim. Biophys. Acta, Gen. Subj. 1986, 883, 155– 161. 10.1016/0304-4165(86)90146-7. 3089298 · DOI
  52. Bothma J. P.; de Boor J.; Divakar U.; Schwenn P. E.; Meredith P. Device-quality Electrically Conducting Melanin Thin Films. Adv. Mater. 2008, 20, 3539– 3542. 10.1002/adma.200703141. · DOI
  53. Kittle J. D.; Wang C.; Qian C.; Zhang Y.; Zhang M.; Roman M.; Morris J. R.; Moore R. B.; Esker A. R. Ultrathin Chitin Films for Nanocomposites and Biosensors. Biomacromolecules 2012, 13, 714– 718. 10.1021/bm201631r. 22263611 · DOI
  54. Cárdenas G.; Cabrera G.; Taboada E.; Miranda S. P. Chitin Characterization by SEM, FTIR, XRD, and 13C Cross Polarization/Mass Angle Spinning NMR. J. Appl. Polym. 2004, 93, 1876– 1885. 10.1002/app.20647. · DOI
  55. Chatterjee S.; Prados-Rosales R.; Itin B.; Casadevall A.; Stark R. E. Solid-State NMR Reveals the Carbon-Based Molecular Architecture of Cryptococcus neoformans Fungal Eumelanins in the Cell Wall. J. Biol. Chem. 2015, 290, 13779– 13790. 10.1074/jbc.m114.618389. 25825492 PMC4447955 · DOI
  56. Forfang K.; Zimmermann B.; Kosa G.; Kohler A.; Shapaval V. FTIR Spectroscopy for Evaluation and Monitoring of Lipid Extraction Efficiency for Oleaginous Fungi. PLoS One 2017, 12, e0170611 10.1371/journal.pone.0170611. 28118388 PMC5261814 · DOI
  57. Manini P.; Lucci V.; Lino V.; Sartini S.; Rossella F.; Falco G.; Chiappe C.; d’Ischia M. Synthetic Mycomelanin Thin Films as Emergent Bio-inspired Interfaces Controlling the Fate of Embryonic Stem Cells. J. Mater. Chem. B 2020, 8, 4412– 4418. 10.1039/d0tb00623h. 32373902 · DOI
  58. Raman N. M.; Ramasamy S. Genetic Validation and Spectroscopic Detailing of DHN-Melanin Extracted From an Environmental Fungus. Biochem. Biophys. Rep. 2017, 12, 98– 107. 10.1016/j.bbrep.2017.08.008. 28955797 PMC5613234 · DOI
  59. Fukamizo T.; Kramer K. J.; Mueller D. D.; Schaefer J.; Garbow J.; Jacob G. S. Analysis of Chitin Structure by Nuclear Magnetic Resonance Spectroscopy and Chitinolytic Enzyme Digestion. Arch. Biochem. Biophys. 1986, 249, 15– 26. 10.1016/0003-9861(86)90555-2. 3740847 · DOI
  60. Tian S.; Garcia-Rivera J.; Yan B.; Casadevall A.; Stark R. E. Unlocking the Molecular Structure of Fungal Melanin Using 13C Biosynthetic Labeling and Solid-State NMR. Biochemistry 2003, 42, 8105– 8109. 10.1021/bi0341859. 12846559 · DOI
  61. Chrissian C.; Camacho E.; Fu M. S.; Prados-Rosales R.; Chatterjee S.; Cordero R. J. B.; Lodge J. K.; Casadevall A.; Stark R. E. Melanin Deposition in Two Cryptococcus Species Depends on Cell-Wall Composition and Flexibility. J. Biol. Chem. 2020, 295, 1815– 1828. 10.1074/jbc.ra119.011949. 31896575 PMC7029119 · DOI
  62. Knicker H.; Almendros G.; González-Vila F. J.; Lüdemann H.-D.; Martin F. 13C and 15N NMR Analysis of Some Fungal Melanins in Comparison with Soil Organic Matter. Org. Geochem. 1995, 23, 1023– 1028. 10.1016/0146-6380(95)00094-1. · DOI
  63. Centeno S. A.; Shamir J. Surface Enhanced Raman Scattering (SERS) and FTIR Characterization of the Sepia Melanin Pigment Used in Works of Art. J. Mol. Struct. 2008, 873, 149– 159. 10.1016/j.molstruc.2007.03.026. · DOI

Cited by

Sorted by citations

Authors
Singla, S., Htut, K. Z., Zhu, R., Davis, A., Ma, J., Ni, Q. Z., Burkart, M. D., Maurer, C., Miyoshi, T., & Dhinojwala, A.
Affiliations
  • University of Akron (US)
  • University of California San Diego (US)
  • redhouse Studio, Cleveland, Ohio 44113, United States
Corresponding author
Dhinojwala, Ali
ORCID
Venue
ACS Omega
Publisher
American Chemical Society (ACS)
Published
2021-12-14
Volume
6
Issue
51
Pages
35514-35522
ISSN
2470-1343 (ISSN-L)
DOI
10.1021/acsomega.1c05030
PMC
PMC8717558
OpenAlex
W4200302805
Cited by
48
References
0
Citations by year
2026: 8 · 2025: 14 · 2024: 14 · 2023: 9 · 2022: 3
FWCI
3.38
Type
journal article
Language
en
Open access
Licence
Locations
  • ACS Omega (publishedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
Air Force Office of Scientific Research (FA9550-18-1-0142)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biotechnology › Microbial Metabolism and Applications
  • Social Sciences › Arts and Humanities › Archeology › Cultural Heritage Materials Analysis
Keywords
melanin extraction, acid-base extraction, UV absorption, antioxidants, invasive plant disease

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review