Liverwort Frullania franciscana Howe was found high on the allergic test scale by J. Mitchell of the Medical School of the University of British Columbia and co-workers. Frullanolide was isolated from Frullania tamarisci by J.D. Connoly and by G. Oisson and his co-workers. The plant sample, collected in Oregon, was hand separated, confirmed, air dried and milled before the extractions were done. A Soxhlet extraction with ether and cold extractions with n-hexane and with ether were carried out. Ether is a better extraction solvent than n-hexane for cold extraction. Column chromatography was used for the separation of the extract based on gradient elution from silica gel or aluminum oxide. Non-polar hydro-carbon sesquiterpenes and other hydrocarbons usually were eluted first. Frullanolide then was eluted. Studies by thin layer chromatography on silica gel showed that none of the fractions was a pure component; therefore, further separations were done by thin layer chromatography and small-scale column chromatography. However, no satisfactory separation systems were found, except that frullanolide was isolated from the silica gel plate with cyclohexanel/ethyl acetate 80/20, Rf' = 25.8, which was very close to the reported value. An infrared spectrum of this was taken and used as supporting evidence. An infrared spectrum of the first fraction from an aluminum oxide column showed that this was a reasonably pure fraction of hydrocarbons. By gas chromatography, eleven components were found in this fraction, and the percentage of the major component was calculated to be 97% by weight. Nuclear magnetic resonance and infrared spectra showed an exo-double bond with a 6-membered ring or larger. (I.R. : 3080 cm-1 ,1643 cm-1 ,888 cm-1, NMR δ 4.73) This fraction was then studied by means of a gas chr0matography-mass spectrometer, and the molecular weight of the main component of this fraction was 204. Kovats’ indices of the main component were taken by co-injection with 0-cedrene and ᵝ-bourbonene; these data, however, did not match any of the compounds listed. Infrared analysis of the other fractions from the columns and from thin layer chromatography showed the presence of carbonyl groups. One of the carbonyl groups absorbed at about 1770 cm-1, characteristic of a y -lactone.

Indiana University-Purdue University Indianapolis (IUPUI) / Regulatory T (Treg) cells represent an important layer of immune-regulation indispensible for curtailing exuberant inflammatory responses and maintaining self-tolerance. Treg cells have translational potential for autoimmunity, inflammation, transplantation and cancer. Therefore, delineating the molecular underpinnings underlying the development, suppressor function and stability of Tregs is particularly warranted. The transcriptional repressor Bcl6 is a critical arbiter of helper T cell fate, promoting the follicular helper (Tfh) lineage while repressing Th1, Th2 and Th17 differentiation. Bcl6-deficient mice develop a spontaneous and severe Th2-type inflammatory disease including myocarditis and pulmonary vasculitis, suggesting a potential role for Bcl6 in Treg cell function. Bcl6-deficient Treg cells are competent in controlling Th1 responses, but fail to control Th2 inflammation in an airway allergen model. Importantly, mice with Bcl6 deleted specifically in the Treg lineage develop severe myocarditis, thus highlighting a critical role for Bcl6 in Treg-mediated control of Th2 inflammation. Bcl6-deficient Tregs display an intrinsic increase in Th2 genes and microRNA-21 (miR-21) expression. MiR-21 is a novel Bcl6 gene target in T cells and ectopic expression of miR-21 directs Th2 differentiation in non-polarized T cells. MiR-21 is up-regulated in mouse models of airway inflammation and also in human patients with eosinophilic esophagitis and asthma. Thus, miR-21 is a clinically relevant biomarker for Th2-type pathologies. Our results define a key function for Bcl6 in repressing Gata3 function and miR-21 expression in Tregs, and provide greater understanding of the control of Th2 inflammatory responses by Treg cells.