1) Regretful 
• (a.) Of the nature of compunction; caused by conscience; attended with, or causing, compunction.
Com·punc'tious adjective Of the nature of compunction; caused by conscience; attended with, or causing, compunction. « That no compunctious visitings of nature Shake my fell purpose. Shak. » 
compunctious, compunctiously Ccausing or feeling compunction; regretful.
causing or feeling compunction; regretful.