Peptide builderType a protected peptide as a chemist writes it — BocGlyAlaOBn, CbzPheGlyOMe, HValLeuOH — and see its structure, its molecular formula, its molecular weight, its monoisotopic mass and its SMILES.Residues are the L amino acids, written with their three-letter codes; the amine takes Boc or Cbz, the acid OH, OMe or OBn.Draw the products and intermediates of a peptide synthesis, from protecting groups to DCC coupling, and follow two slide shows. The exercises need JavaScript, because every drawing is checked in your browser.

Why protect — heat two amino acids, and count what forms

Protecting groups — put them on, take them off

Coupling with DCC — activate the acid, then form the amide

Planning a synthesis — protect, couple, deprotect, in the right order

Builder — type a sequence, see the molecule

Cheatsheet — every group, how it goes on and comes off

Talks — two slide shows, mechanisms included

About — what the site is, and how to cite it

Our other tools

learn.cheminfo.org — Arrange the tools into a course and hand out its link.

inchi.cheminfo.org — InChI and InChIKey from a structure, in the browser.

vcl.cheminfo.org — Combine a core and fragments into a screened library.

smiles.cheminfo.org — Draw a structure, read its SMILES, learn the notation.

iupac-name.cheminfo.org — The IUPAC name of a structure, and the structure a name denotes.

openbabel.cheminfo.org — Convert a structure between any pair of chemical file formats.

www.chemcalc.org — Molecular formula, exact mass and isotopic distribution.

dbe.cheminfo.org — Count rings and double bonds from a formula or a structure.

metabo.nmrium.com — Turn a batch of NMR spectra into a map of your samples.

derepflow.cheminfo.org — Identify the constituents of a mixture from its ¹³C spectrum.

isomers.cheminfo.org — Every constitutional isomer of a molecular formula.

tex.cheminfo.org — Write LaTeX and mhchem formulas, and save them as SVG.

lcao.cheminfo.org — Combine atomic orbitals into molecular ones.

regexp.cheminfo.org — Learn regular expressions in a live playground.

pdb.cheminfo.org — A fast look at any Protein Data Bank entry.

elucidation.cheminfo.org — A structure from a 1H NMR spectrum and a formula.

spectroscopy.cheminfo.org — Find a structure from its IR, mass and NMR spectra.

equilibrium.cheminfo.org — Chemical equilibria: pH, speciation and titration curves.

polycarp.cheminfo.org — Predict the microstructure of a radical copolymerisation.

3d.cheminfo.org — Conformers in 3D from a structure you draw.

periodic-table.cheminfo.org — The periodic table, coloured, plotted and taken apart.

database.cheminfo.org — Query a real chemical dataset in SQL and in Mango.

chembio.cheminfo.org — Natural products, and the organisms they were found in.

wikidata.cheminfo.org — The chemistry of Wikipedia’s infoboxes, searchable by structure.

symmetry.cheminfo.org — Find the symmetry of a molecule, a crystal or a pattern.

osiris.cheminfo.org — Predicted toxicity risks and properties, one molecule or many.

atoms.cheminfo.org — Electrons, neutrons, Lewis structures and oxidation states.

moles.cheminfo.org — Balance a reaction, and work out its mass composition.

inorganic.cheminfo.org — Name an inorganic compound, and write its formula.

slides.cheminfo.org — Put a live tool on a slide, from the link its Share button gives.

vibrations.cheminfo.org — IR and Raman spectra computed in the browser.

draw.cheminfo.org — Journal-grade structures, in an SVG that keeps the chemistry.

plate.cheminfo.org — Read a TLC plate, a gel or a blot from a photograph.

glassware.cheminfo.org — Assemble lab glassware into a working apparatus, and draw it.

write.cheminfo.org — Write documents holding structures, 3D models and plates that open again where they were made.