Haworth Projection
A Haworth projection draws a cyclic sugar as a flat ring seen edge-on, with the front edge bold and the back edge thin, and substituents pointing straight up or down from each ring carbon. Molkit builds the ring from real atoms and bonds linked to a projection annotation, so the ring and its groups stay editable after placement.
Place a Haworth ring
Open the projection tool flyout and pick a Haworth variant from the Haworth row, then click on the canvas to drop the ring at that point. Two ring sizes are available:
- Haworth (pyranose) builds a six-membered ring.
- Haworth (furanose) builds a five-membered ring.
After placement, Molkit selects the new atoms and switches to the select tool. The ring oxygen sits at the top-right position and is shown as an O label; the ring carbons are drawn as the line vertices and stay unlabeled. Every carbon starts with an up substituent and a down substituent, each defaulting to H.
The flat-ring perspective
Front ring edges (the lower edge nearest the viewer) render as bold wedges, and back edges render as thin lines. Molkit decides front versus back from each bond’s vertical position relative to the ring center, so the bold edge stays correct as you move the ring or resize it. Substituent bonds run vertically from each carbon: one up, one down.
Edit substituents
To change a substituent, double-click its atom to open the label editor, then type the group you want (for example OH or CH₂OH). The ring vertices themselves are treated as ring atoms, so a plain double-click on an edge carbon does not open the label editor; only the up and down groups are editable this way. To relabel a ring atom anyway (for example a second ring oxygen), select it first, then double-click it.
Projection Properties panel
Select the projection to open the Projection Properties panel, which shows a Haworth section with sliders and a color control:
- Ring width and Ring height set the overall ring footprint.
- Substituent length sets how far the up/down groups extend from each carbon.
- Line thickness sets the thin (back-edge) stroke width.
- Bold thickness sets the front-edge wedge width.
- Color overrides the ring color; clear it to fall back to the document bond color.