Miroslav Holub

Sesquiterpene lactones of the umbelliferae

Abstract A survey of sesquiterpene lactones from the species of Umbelliferae is presented. The structures based on predominantly undescribed stereostructural types were derived for the majority of these lactones.

POTENTIALITIES OF THE SMALL LYMPHOCYTE AS REVEALED BY HOMOTRANSPLANTATION AND AUTOTRANSPLANTATION EXPERIMENTS IN DIFFUSION CHAMBERS

The small lymphocyte as a cell type is one of the lasting problems of pathology, hematology, and the morphological interpretation of antibody formation and transplantation immunity. The defense against foreign tissues appears to be one of the basic functions of the small lymphocyte (Snell et al., 1961). An increasing number of papers deals with the role and significance of individual lymphocytic types in homograf t response, in Simonsen’s phenomenon, and in the induction of runt disease (Medawar, 1958; Anderson et al., 1960; Cole and Garver, 1961; Szenberg and Warner, 1961). Even small lymphocytes seem to be involved; for example, in graft-versus-host reaction in the chicken (Terasaki, 1959). The method of diffusion chamber cultivation was found appropriate for observing the potentialities of lymphocytes (Shelton and Rice, 1959; Schooley and Berman, 1960; Holub, 1958, 1960). T h e possibility of separating practically pure suspensions of small thoracic duct lymphocytes enabled us to obtain direct evidence about the nature of these cells. The comparison of cultivations of small lymphocytes in autotransplantation and homotransplant at ion experiments in diffusion chambers provides the possibility of estimating the cellular changes caused also by tissue antigens.

Deterrent activity of sesquiterpene lactones from the umbelliferae against storage pests

Abstract The deterrent activity of eight native sesquiterpene lactones isolated from the species Laserpitium siler L., L. archangelica Wulf. and Laser trilobum (L.) Borkh. and one synthetically prepared lactone have been tested against selected storage pest insects. All nine lactones under investigation showed deterrent activity differing according to their structure.

The phylogenetic relationships of the Asteraceae and Apiaceae based on phytochemical characters

Abstract Phylogenetic relationships between the families Asteraceae (Compositae) and Apiaceae (Umbelliferae) are discussed, mainly on the basis of the stereostructures of the sesquiterpene lactones present in species of both families. It is concluded that the stereostructural parallelism of sesquiterpene lactones suggests a parallel phylogenesy of both families and their independent position in different subclasses.

A New sesquiterpene ester from ferula tingitana

Abstract A new sesquiterpene ester, tingitanol, isolated from Ferula tingitana L., is assigned as 1β,3β-dihydroxy-4α,8α-diangeloyloxydauc-5-ene on the basis of spectral, analytical, and X-ray data.

Experimental allergic encephalomyelitis: changes in growth and proliferation within the draining lymph node following injection of basic encephalitogenic protein in Freund's complete adjuvant.

Abstract Changes in wet weight, dry mass, and DNA synthesis of draining lymph nodes from rats injected with encephalitogenic basic protein in Freunds complete adjuvant (FCA) were studied. Lymph nodes of rats injected with encephalitogenic basic protein in FCA show accelerated enlargement from the second up to the fourth day after injection, as compared to lymph nodes of rats injected with FCA alone, or with nonencephalitogenic basic protein in FCA. The greatest difference in lymph node weight was found on the fourth day. At this time cell division is higher in the group injected with encephalitogenic protein in FCA than in the group injected with FCA alone. However, the increased division of cells in situ cannot account, in and by itself, for the enlargement of the lymph node which was observed. It is concluded that migration of lymphocytes into the lymph node makes a substantial contribution to the hyperplasia of the lymph node. The results suggest that accelerated lymph node enlargement may be specific, at least in part, for induction of experimental allergic encephalomyelitis.

Sesquiterpene lactones of new stereostructural types from laser trilobum

Abstract The newly established structures of sesquiterpene lactones from Laser trilobum showed that these lactones belong among the stereostructural types of germacranolides, guaianolides, eudesmanolides and elemanolides.

Germacra-1(10),4-diene-cis-6,12-olides: a novel stereochemical group of natural sesquiterpenic lactones from ursinia anthemoides (L.) poiret ☆

Abstract New stereochemical group of germacranolides - germacra-1(20),4-diene-cis-6,12-olides - was identified on the basis of 1H-NMR and X-ray analysis.

5βH,6αH,7αH,10αCH3-eudesman-6,12-olides: A novel stereochemical group of natural sesquiterpene lactones. Stereostructure of isosilerolide

Abstract A new stereochemical group of eudesmanolides - 5βH,6αH,7αH,10αCH 3 -eudesman-6,12-olides - was identified mainly on the basis of proton NMR spectroscopy and checked by X-ray analysis

Structure of isolaserolide from Laser trilobum

Abstract The structure I has been deduced for isolaserolide on the basis of its PMR spectrum and the chemical correlation with laserolide (II). Isolaserolide is the first elemanolide isolated from the Umbelliferae.