The angular distributions of the baryon-antibaryon low-mass enhancements seen in the charmless three-body baryonic B decays B+ -> ppK(+), B-0 -> ppK(S)(0) and B-0 -> p Lambda pi(-) are reported. A quark fragmentation interpretation is supported, while the gluonic resonance picture is disfavored. Searches for the Theta(+) and Theta(++) pentaquarks in the relevant decay modes and possible glueball states G with 2.2 GeV/c(2) < M-pp < 2.4 GeV/c(2) in the pp systems give null results. We set upper limits on the products of branching fractions, B(B-0 -> Theta(+)p)B(Theta(+) -> pK(S)(0)) < 2.3 x 10(-7), B(B+ -> Theta(++)p)B(Theta(++) -> pK(+)) < 9.1 x 10(-8), and B(B+ -> GK(+))B(G -> pp) < 4.1 X 10(-7) at the 90% confidence level. The analysis is based on a 140 fb(-1) data sample recorded on the Y(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. (c) 2005 Elsevier B.V. All rights reserved.