JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/dojo/1.7/dijit/themes/claro/claro.css">
JavaScript
var reg = /\w+\s?(?=,|$)/igm;
var str = "keyword2 : (content2), app, keyword1 : (content1), sos, key word : (content), das";
console.info(str.match(reg));