Epicuticular wax variability of Juniperus deltoides R.P. Adams from the central Balkan – Ecology and chemophenetics

Juniperus deltoides R.P.Adams is a prickly, evergreen shrub that grows in the East Mediterranean on dry hills and mountains. Needle-like leaves have a thick cuticular layer on the surface, which serves as the ultimate barrier for prevention of water loss. n-Alkanes comprise the biggest part of this hydrophobic wax mixture. These compounds are studied as chemophenetic characters due to their chemical and physiological stability, and strong genetic control. Six central Balkan populations were studied and compared to one eastern and one western. Fifteen n-alkanes were identified, with C33 being dominant in all samples. Univariate and multivariate statistical analyses separated western population from all central Balkan populations, while the eastern Balkan population showed high similarity with the central ones. Climatic, orographic and pedological characteristics of the studied localities were also taken into account.     

Two new sesquiterpenoids and one new p-coumaroyl-triterpenoid derivative from Myrcia guianensis

Two new sesquiterpenoids (1 and 2) and one new p-coumaroyl-triterpenoid derivative (3), along with five known sesquiterpenoids (4–8), seven triterpenoids (9–15), and two steroids (16 and 17) were isolated from Myrcia guianensis. Compound 1 [6-methyl-5-(2-hydroxy-3-chloro-5-methyl phenyl)-heptan-2-one] contains a chlorine atom attached to C-10, which seems to be the first report of a chlorine-containing sesquiterpenoid in the Myrtaceae family. The biogenesis of the two new sesquiterpenoids (1 and 2) are proposed herein, whereas the isolation of these sesquiterpenoids and triterpenoids from M. guianensis may present chemophenetic relevance to consolidate the genus Myrcia within the Myrtaceae family.     

Cecropia telenitida Cuatrec. (Urticaceae: Cecropieae): Phytochemical diversity,chemophenetic implications and new records from Central America

The Neotropical genus Cecropia is the largest genus of Cecropieae in the Urticaceae family with 61 described species. For many years, the taxonomic study of Cecropia has been based on morphological and anatomical data. However, recent studies have shown that chemical entities present in Cecropia can be used to establish differences between species providing important additional support on its taxonomic classification. The goal of the present study was to contribute to the phytotaxonomic knowledge of this genus to better inform taxonomic decisions. In addition, this is the first time that chemical constituents have been described in the leaves of Cecropia telenitida Cuatrec., a species that until now had not been reported in Central America. We characterized and quantified the polyphenolic composition of the methanol leaf extract of C. telenitida using UPLC-DAD-MS and HPLC-DAD, respectively. Phytochemical analysis showed that this extract was rich in chlorogenic acid and flavone C-glycosides, with isoorientin and isoorientin 2″-O-xyloside as the main compounds. Our data showed a lower chemical diversity and metabolite concentrations than other related species. Morphological, distributional and taxonomic notes, images of the plant and phytochemical comparisons between C. telenitida and selected congeners from Panama are also provided.     

Essential oil composition of five Artemisia (Compositae) species in regards to chemophenetics

In this work we analysed the essential oils (EO) obtained by hydrodistillation from the aerial parts of five Artemisia species (A. arborescens L., A. campestris L., A. lobelii All., A. annua L. and A. absinthium L.) originated from Serbia, Montenegro, and Libya, by gas chromatography coupled with mass spectrometry. In total, 126 compounds were detected, and 120 were identified. Even though a high number of compounds were detected, each individual sample had only 25 to 50, attesting to a great diversity of compounds between taxa. Depending on the species and the locality (geographical origin), EO was dominated by either monoterpenes or sesquiterpenes, with β-pinene, chamazulene, germacrene D, camphor, pinocarvone and thuja-2,4(10)-diene being the dominant compounds. The chemophenetic value of the EO compositions was discussed in relation to the results of the multivariate statistical test, including the detailed survey of the available literature data.     

Secondary metabolites of Rubus caesius (Rosaceae)

The European dewberry (Rubus caesius) is a perennial shrub that is widely distributed in Europe but can also be found in North America. In folk medicine, the European dewberry is used to treat hyperglycaemia, diarrhoea and inflammation. LC-MS analysis of the European dewberry confirmed the presence of 35 compounds, mostly flavonoids, phenolic acids and derivatives of ellagic acid. Phytochemical analysis of R. caesius leaves led to the isolation of nine phenolics, namely: quercetin 3-O-β-D-rutinoside (1), kaempferol 3-O-β-D-glucuronide (2), quercetin 3-O-β-D-glucuronide (3), methyl brevifolincarboxylate (4), kaempferol 3-O-β-D-(6″-O-(E)-p-coumaroyl)-glucoside (5), kaempferol (6), quercetin (7), pedunculagin (8), and ellagic acid (9). Compounds 1–8 were isolated from this species for the first time. The chemophenetic significance was discussed.     

Sesquiterpene lactones and other secondary metabolites from Crepis commutata (Spreng.) Greuter – Asteraceae

Sesquiterpene lactones, especially guaianolides, are widespread in the genus Crepis L. We have undertaken the chemical investigation of Crepis commutata (Spreng.) Greuter, an edible plant in Crete. From the non-polar extract of the aerial flowering parts of C. commutata five sesquiterpene lactones: 8-epi-grosheimin (1), 8-epi-isoamberboin (2), 8-epi-isolipidiol (3), 3-acetyl-8-epi-isolipidiol (4), integrifolin 3-O-β-D-glucopyranoside (5), two flavonoids: luteolin (6), luteolin 7-O-β-D-glucuronide (7), and three phenolic acids: p-anisic acid (8), p-hydroxyphenylacetic acid (9) and E-caffeic acid (10) were isolated. The structures of the isolated compounds were elucidated by high-field NMR spectroscopy.     

Chemical constituents from the leaves and branches of Annona coriacea Mart. (Annonaceae)

The phytochemical investigation of the leaves and branches of Annona coriacea Mart. (Annonaceae) led to the isolation and characterization of eight compounds: five isoquinoline-derived alkaloids, including pukateine (1), liriodenine (4), anonaine (5), obovanine (6), and norisocorydine (7); one terpene lactone known as loliolide (3); one benzoic acid derivative, 2-methoxybenzoic acid (2), and 3,4,5-trimethoxyphenol (8). All compounds, except liriodenine, are being described for the first time in the species A. coriacea, and their chemophenetics relationships were discussed. The structures were elucidated by extensive analyses of 1D and 2D NMR (COSY, HSQC, and HMBC) spectroscopy in combination with MS, and the data were compared with literature values. The NMR dataset of pukateine and obovanine was reviewed. Our results showed that A. coriacea is a typical species of the Annonaceae family and an important source of aporphine alkaloids with chemophenetic relationships with Xylopia, Duguetia, Guatteria, Artabotrys, and Goniothalamus genera.     

Isoquinoline-derived alkaloids and one terpene lactone from the leaves of Duguetia pycnastera (Annonaceae)

The phytochemical investigation from the leaves of Duguetia pycnastera Sandwith (Annonaceae) led to the isolation and identification of ten compounds: nine isoquinoline-derived alkaloids, including five aporphines, anonaine, isopiline, O-methylisopiline, nornuciferine, and norstephalagine; three oxoaporphines, O-methylmoschatoline, liriodenine, and lysicamine; and one tetrahydroprotoberberine, isocorypalmine; in addition, one C₁₁-terpene lactone known as loliolide. The isolated compounds (except for O-methylmochatoline and lysicamine) are described for the first time in the species and their chemophenetics relationships were discussed. The occurrence of loliolide is reported for the first time in the Duguetia. The structure elucidation of these compounds was established by extensive analyzes of 1D and 2D NMR spectroscopy in combination with MS. The NMR spectroscopic data for norstephalagine and isocorypalmine were reviewed.     

Leaf cuticular waxes of Tanaecium (Bignonieae,Bignoniaceae): Chemical composition and taxonomic implications

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