(±)trans-2,5-bis-(3,4,5-Trimethoxyphenyl)-1,3-dioxolane, also known as trans-BTP Dioxolane, is a PAF receptor antagonist [1].

Platelet activating factor (PAF), a phospholipid mediator of inflammation, is secreted by several cell types including arterial endothelial cells, and can activate polymorphonuclear leucocytes and monocytes via specific cell surface receptors. PAF also stimulates the production of active oxygen species by human monocyte - derived macrophages. PAF play important roles in a variety of pathophysiological states including acute allergy, inflammation, asthma, gastrointestinal ulceration, and toxic shock [1].

(±)trans-2,5-bis-(3,4,5-Trimethoxyphenyl)-1,3-dioxolane is a PAF receptor antagonist. In the rabbit washed platelet assay, (±)trans-2,5-bis-(3,4,5-Trimethoxyphenyl)-1,3-dioxolane showed good competitive PAF antagonism with Ki value of 0.3 μM, whereas the cis-isomer was much less active.

Reference:
[1].  Corey, E.J.,Chen, C.P., and Parry, M.J. Dual binding modes to the receptor for platelet activating factor (PAF) of anti-PAF trans-2,5-diarylfurans. Tetrahedron Letters 29, 2899-2902 (1988).