using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string str = "<div class=\"whois_result\" id=\"registryData\">Domain Name: CASASBAHIACOMPRAS.COM<br>Registrar: 1 API GMBH<br>Sponsoring Registrar IANA ID: 1387<br>Whois Server: whois.1api.net<br>Referral URL: http://www.1api.net<br>Name Server: EVA.NS.CLOUDFLARE.COM<br>Name Server: VERN.NS.CLOUDFLARE.COM<br>Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited<br>Updated Date: 04-apr-2016<br>Creation Date: 31-mar-2016<br>Expiration Date: 31-mar-2017<br></div>";

        var conteudo = Regex.Replace(str,"<div.*?>","").Replace("</div>","");

        Console.WriteLine(conteudo);

    }

}