Ara(b1-2)Ara(a1-3)[Ara(b1-2)Ara(a1-5)]Ara(b1-5)[5)Ara(a1-]n[Ara(b1-2)Ara(a1-3)[Ara(b1-2)Ara(a1-5)]Ara(b1-5)[5)Ara(a1-]n]Ara(a1-5)[5)Ara(a1-]n