I want latest events like the example below, remove the other events without using dedup command,
time : 4/9/2015 15:00:01 :-----host:foo1, source:foo2, source type:foo3, Date:foo4,status=foo5,Name=foo6.
Why do you want to avoid using dedup? Dedup is by far the easiest way of doing this. Just |dedup host, source, sourcetype, Date, Name | , and that's all you need to do. Add that before the transaction.
Dedup will leave you with the most recent result from each duplicate set.
From the docs: "Events returned by dedup will be the first event found in search order, which is the most recent for historical search"