Other than spelling "aeiou up", there are no anagrams.
The smaller words that can be made are :
a, ape, pa, pi, pea, pie, poi, and up.
Those letters spell natural.
The letters in "these letters" can spell the phrase "ether settles." The letters can spell shorter words such as trestles, sheerest, shelters, and treeless.
Those letters will spell dollar.
The letters spell 'broccoli'.
Those letters spell psycho.
Those letters will spell carnivore.
The letters can spell the anagram "annotation."
Those letters will spell democratic.
Those letters will spell turnip.
Those letters will spell artichoke.
Those letters will spell hairy.
The letters spell the word temples.