SimpleXMLElement gete element or convert to array

I have SimpleXMLElement and I neeed get content filed (10) I try

        $xml   = simplexml_load_string($summContent);
    $array = json_decode(json_encode((array) $xml), 1);
    $array = array($xml->getName() => $array);

but have xml - false and array - false

$summContent = {SimpleXMLElement} [6]
id = "https://spreadsheets.google.com/feeds/cells/1-fR7MXmjsr0juPWsbpK9RSY_WVW_XK77-krsmEcmdc4/oxi7ruj/private/full/R14C2"
updated = "2016-07-26T10:49:49.902Z"
category = {SimpleXMLElement} [1]
title = "B14"
content = "10"
link = {array} [2]

I try $summContent->content :

result = {SimpleXMLElement} [2]
@attributes = {array} [1]
0 = "10"

Waing: simplexml_load_string(): Entity: line 1: parser error : Start tag expected, '<' not found

hot to convert to array ?