Punctatin: A new germacradienolide from Liatris punctata

The isolation and structure determination of punctatin (I), a new germacradienolide from Liatris punctata Hook., is reported. The flavone eupatilin was also found.     

A new dihydrobenzofuran from Liatris provincialis

A chloroform extract of Liatris provincialis Godfrey gave as a minor component a new dihydrobenzofuran, whose structure was established as I.     

Additional alkaloids from Laurelia philippiana and L. novae-zelandiae

Asimilobine, anonaine, noreorydine, nornantenine, (+)-reticuline and the new alkaloid, 4-hydroxyanonaine, were isolated from Laurelia philippiana bark. The biogenetically related obovanine, oxoputerine and (?)-romneine, not known as a natural product, were obtained from the bark of L. novae-zelandiae. The occurrence of (R)-norlaudanosoline-derived alkaloids in L. novae-zelandiae is a distinctive feature of this tree. Neither L. novae-zelandiae nor L. philippiana accumulate dimeric benzylisoquinoline alkaloids to any appreciable extent in the trunk bark, differing in this respect from L. sempervirens, the only other Laurelia species.     

Guaianolides and heliangolides from Hymenopappus newberryi

The aerial parts of Hymenopappus newberryi afforded two heliangolides, two thymol derivatives, as well as two new guaianolides and a trans, trans-germacranolide closely related to hiyodorilactone A. Furthermore, the ent-kaurene derivative abbeokutone was present. These results are of chemotaxonomic interest.     

Guaianolides from Liatris squarrosa

The isolation of three new guaianolides related to spicatin from Liatris squarrosa is reported.     

Stereochemistry of chapliatrin and its congeners from Liatris gracilis

Re-examination of Liatris gracilis afforded the known sesquiterpene lactones chapliatrin, isochapliatrin, acetlisochapliatrin, five new closely related 5,10-epoxygermacranolides and a new eudesmanolide. The stereochemistry of the 5,10-epoxygermacranolides has been settled by an X-ray analysis of isochapliatrin.     

Sesquiterpene lactones and other constituents of Eupatorium lancifolium and E. semiserratum

The isolation of the cytotoxic and/or antileukaemic heliangolides eupacunolin, eupacunin, desacetyleupacunin, a new germacradienolide and a coumarin fr     

New germacrolide- and heliangolide-type sesquiterpene lactones from Melampodium linearilobum

Chemical analysis of Melampodium linearilobum yielded, besides coumarin, seven germacrolide-type sesquiterpene lactones, linearilobin A to G and two heliangolides, linearilobin H and I. All new sesquiterpene lactones are oxygenated at C-14 and C-15 and differ by the number and types of ester moieties at C-8, C-14 and C-15. M. linearilobum represents the first species within the genus known to produce germacrolides and heliangolides instead of the more common melampolides.     

Sesquiterpene lactones from Centaurea glomerata

The investigation of the aerial parts of Centaurea glomerata afforded four new sesquiterpene lactones of the germacradienolide type and the lignan lactone arctigenin. Their structures were elucidated by spectroscopic methods.     

Sesquiterpene lactones and other constituents of Disynaphia multicrenulata from Argentina

Flowers and leaves of Disynaphia multicrenulata from Argentina afforded a large number of known germacradienolides and heliangolides, a new germacradienolide, a known melampolide, a new parthenolide derivative, one known and seven new cronquistiolides, a new 4Z-melampolide, three known and five new eudesmanolides, a new elemadienolide, a known grazielolide, an isoguaiagrazielolide, two diepoxygermacran-8,12-olides, three common kauranoic acids, pinoresinol, jaceosidin and the sesquiterpene oplopanone. Structures were elucidated by high-field 1H NMR spectrometry. The relationship to the known chemistry of other members of the Disynaphiinae is discussed.     

Sesquiterpene lactones and diterpene carboxylic acids in Helianthus niveus subspecies Canescens

Three new heliangolides (niveusin-A, -B and -C) and three known diterpene carboxylic acids were isolated and characterized from a CHCl₃, extract of Helianthus niveus. The structures of the three new lactones were deduced by ¹H and ¹³C NMR as well as extensive decoupling experiments and derivatizations.     

A glycosidic germacradienolide from Eupatorium altissimum

The isolation and structure determination of a glycosidic germacradienolide from Eupatorium altissimum are reported. Eupatorin and 5-hydroxy-3′,4′,6,7-tetramethoxyflavone were also found.     

Hybridizations and genetic relationships among Lindernia species (Scrophulariaceae): L. procumbens and two subspecies of L. dubia

Lindernia procumbens and L. dubia are common annual weeds in flooded rice fields of Japan. Two subspecies of L. dubia, subsp. major and subsp. dubia, are usually recognized in Japan but they are both regarded as synonyms of L. dubia elsewhere. In a cluster analysis based on AFLP, most L. dubia subsp. major formed a separate cluster from L. dubia subsp. dubia although 11% of haplotypes classified using AFLP were not coincident with classification using the shape of leaf bases, which is the commonly used identification trait. Artificial F₁ plants between L. procumbens and L. dubia subsp. major, and between L. procumbens and L. dubia subsp. dubia did not produce seed. Forty percent of capsules produced by F₁ plants from these two subspecies were slimmer and 80% pollen were sterile in slimmer capsules. However, seed number of most F₁ capsules was not different from that of self-fertilized plants, suggesting that there was no complete reproductive isolation between the subspecies. Natural hybridization of these subspecies may have occurred but we are not aware of it because F₁ plants are rare and F₂ plants are indistinguishable from these subspecies.     

Germacranolides from Viguiera microphylla

Three new germacranolides, including two heliangolides (niveusin C-2′,3′-epoxide and 1,2-dehydroniveusin C-2′,3′-epoxide) and a germacrolide (3β-hydroxy-8β-epoxyangeloyloxycostunolide-1β,10α-epoxide) were isolated from Viguiera microphylla. Their structures were established by spectroscopic analyses, including extensive ¹H NMR and ¹³C NMR decoupling experiments and chemical transformations. X-ray diffraction analysis confirmed the structure of niveusin C-2′,3′-epoxide.     

Sesquiterpenes and acetylenes from Argyranthemum adauctum ssp. jacobaeifolium

The roots of Argyranthemum adauctum ssp. jacobaeifolium, a rare endemic from Gran Canaria, afforded two new derivatives of the aromatic acetylene frutescin and 8-isovaleryloxymyrcene, while the aerial parts gave a new bisabolol derivative. Furthermore several known compounds were isolated. The structures were elucidated by high field ¹H NMR spectroscopy and a few chemical reactions.     

3-Germacren-612-olides,from an undescribed liatris taxon

A previously undescribed variant of Liatris gracilis whose taxonomic status is still uncertain furnished a series of 3-germacren-6,12-olides different from the chapliatrin analogues found in authentic L. gracilis. The stereochemistry of one of the new sesquiterpene lactones was established by X-ray diffraction. A eudesmanolide previously isolated from L. gracilis was also found in the variant.     

Three new 5,10-epoxygermacranolides from Liatris chapmanii and Liatris gracilis

Examination of Liatris chapmanii (T + G) Kuntze led to the isolation of two new germacranolides, chapliatrin (1a) and isochapliatrin (1b). Liatris gracilis Pursh gave chapliatrin and acetylchapliatrin 1c). The stereochemistry assigned to C-3, C-4 and C-10 is tentative. All three compounds possess the hitherto-unreported 5,10-oxygen linkage. L. gracilis also gave the benzofuran euparin (2) and the flavones hispidulin (dinatin, 3a and 3′,6-dimethoxy-4′,5,7-trihydroxyflavone (3b). L. chapimanii also gave 5-hydroxy-3′,4′,6,7-tetramethoxyflavone (3c).     

Sesquiterpene lactones of eupatorium anomalum and eupatorium mohrii

Several new guaianolides and the previously known heliangolide eurecurvin have been isolated from Eupatorium anomalum. Eupatorium mohrii also yielded three of the new guaianolides together with eurecurvin and a new germacradienolide. The implications of these findings are discussed.     

Development of species-specific PCR and PCR-restriction fragment length polymorphism assays for L.infantum/L.donovani discrimination

Discrimination of Leishmaniainfantum and L. donovani, the members of the L. (L.) donovani complex, is important for diagnosis and epidemiological studies of visceral leishmaniasis (VL). We have developed two molecular tools including a restriction fragment length polymorphisms of amplified DNA (PCR-RFLP) and a PCR that are capable to discriminate L. donovani from L. infantum. Typing of the complex was performed by a simple PCR of cysteineproteaseB (cpb) gene followed by digestion with DraIII. The enzyme cuts the 741-bp amplicon of L. donovani into 400 and 341 bp fragments whereas the 702 bp of L. infantum remains intact. The designed PCR species-specific primer pair is specific for L. donovani and is capable of amplifying a 317 bp of 3’ end of cpb gene of L. donovani whereas it does not generate an amplicon for L. infantum. The species-specific primers and the restriction enzyme were designed based on a 39 bp insertion/deletion (indel) in the middle of the cpb gene. Both assays could differentiate correctly the two species and are reliable and high-throughput alternatives for molecular diagnosis and epidemiological studies of VL in various foci.     

Guaianolides,heliangolides, diterpenes and cycloartenol derivatives from Balsamorhiza sagittata

Investigation of the aerial parts of Balsamorhiza sagittata afforded 12 new sesquiterpene lactones, five guaianolides, three heliangolides, three germacranolides and two geranylnerol derivatives. From the roots eight cycloartane derivatives, a hydroxylanosterone and hexacos-1-ene were isolated. Structures were elucidated mainly by spectroscopic methods, especially high field NMR. The chemotaxonomic situation is discussed briefly.