Instead of storing the actual html in the string, why not just store the URL in the constants.
export const LINK1 = 'https://sample.com/';
Then in the component you can store this in a variable and use it on the HTML.
TS
import { LINK1 } from './path-to-constants';
...
...
@Component({ ... });
export class SomeComponent {
link = LINK1;
...
HTML:
<a [href]="link">LINK 1</a>
If you definetly want to store the HTML as a string, then you can use [innerHTML] to convert the string to HTML.
The downside of this approach is that, angular features like property binding, event binding do not work using this method.
CONSTANTS
export const LINK1 = '<a href='https://sample.com/'>LINK 1</a>';
TS
import { LINK1 } from './path-to-constants';
...
...
@Component({ ... });
export class SomeComponent {
link = LINK1;
...
HTML:
<span [innerHTML]="link"></span>
export const LINK1 = "<a href='https://sample.com/'>LINK 1</a>";, see that you always can enclosed an expression with singles quotes using double quotes -viceverse is true also-