Biochemical Systematics and Ecology最新文献

The Sanetti Plateau is Africa's largest Afro-alpine ecosystem. As part of an ongoing effort to reconstruct the paleo-extent of Ericaceous vegetation in this ecosystem, we aim to identify unambiguous Erica biomarkers. Here, we present a respective study focusing on plant-derived terpenoids. Terpenoids from seven keystone plant species were identified and quantified using gas chromatography-mass spectrometry (GC-MS). Widely employed angiosperm biomarkers such as lupane, oleanane, ursane, and taraxastane-type triterpenoid alcohols, acids, and esters were detected with a more ample presence in Erica species and Lobelia rhynchopetalum. Ursolic acid is always the predominant triterpenoid, followed by oleanolic acid. The beta- and alpha-amyrin triterpenoids allowed distinguishing Erica trimera from the other plants in hierarchical cluster analysis (HCA). The nearly exclusive presence of amyrin acetate in particular and the total terpenoid content in Erica species corroborate the potential of terpenoid biomarkers for reconstructing the paleo-extent of Ericaceous vegetation in the soil and sediments. Moreover, 3beta-taraxerol may serve as a proxy to distinguish the morphologically and ecologically very similar Erica trimera and Erica arborea. Given that the diagenetic alteration of taraxerol as well as other terpenoid biomarkers should not be overlooked, ongoing research is needed and encouraged to address this issue.

The present study deals with the phytochemical study of the leaf extract of C. klainei, a plant used in folk medicine to treat diabetes, venereal diseases, hypertension, malaria, cough and hemorrhoids. The liquid-liquid extraction and chromatographic separation of the dichloromethane/methanol (1:1) extract of this plant led to the isolation of eleven (11) known compounds identified from the analysis of their spectroscopic and physical data, and in comparison, with data from the literature. These compounds were identified to hentriancontane (1), β-sitosterol (2), stigmasterol (3), β-amyrin (4), betulinic acid (5), sitosterol-3-O-β-D-glucopyranoside (6), diosmetin (7), iristectorigenin A (8), gallic acid (9), bergenin (10) and scyllitol (11) respectively. Furthermore, the chemotaxonomic significance of these compounds was discussed.

One new flavan (1), besides four known flavanones (2–5), was isolated from the aerial parts of Cyperus conglomeratus Rottb. Their structures were established by spectroscopic methods including one and two-dimensional NMR and high-resolution MS. Their antidiabetic activity was evaluated by measuring the inhibitory effect on α-amylase, α-glucosidase, and glycogen phosphorylase. The prebiotic activity was assessed utilizing two probiotic Lacticaseibacillus strains. The effect of the compounds on the enzyme profile of the tested probiotic strains was also evaluated. The promising activity against the tested enzymes was shown by compounds 2 and 4. All compounds exhibited an enhancement in alkaline phosphatase activity in the enzyme profile of Lb. rhamnosus and Lb. paracasei. This study demonstrated that the isolated flavonoids could be used as dietary supplements or in the development of functional foods for diabetes and prebiotics.

Glucosinolates (GSLs) are secondary metabolites mainly found in the plant order Brassicales. We critically evaluate reports of GSLs in other orders of flowering plants, propose standards for future reports and subject two cases to rigorous testing. Reports of GSLs in non-Brassicales species should live up to state-of-the-art scientific standards concerning chemical evidence, botanical evidence and biological replication. Occurrence of GSLs in the family Putranjivaceae, order Malpighiales (genera Putranjiva and Drypetes) was reasonably supported, but state-of-the-art confirmation was required. Hence, the taxonomic identity of Putranjiva roxbughii seeds with the previously known GSL profile was confirmed using DNA-based methods. Similarly, good suggestive evidence exist from the family Violaceae, order Malpighiales, but in need of confirmation. No other report of any GSL in a non-Brassicales species meet the proposed scientific standards, but suggestive evidence exists for the family Phytolaccaceae, order Caryophyllales and to a lesser extent family Celastraceae, order Celastrales. A recent report of a GSL in a tropical plant suggested to be a species in the order Sapindales was subjected to a rigorous testing in terms of chemical analysis, biological replication and botanical identification including DNA sequencing. We confirmed the original report concerning chemical structure and reproducibility but revised the botanical identification to a species from the Brassicales order (family Capparidaceae). Hence this paper also reports myrosinase activity, isothiocyanate-type GSL products from roots and stems, and GSL profile of roots, stems, leaves and fruits of Capparis sepiaria L., dominated by Leu-derived 2-methylpropyl GSL in vegetative parts, Val-derived 1-methylethyl GSL and Ile-derived 1-methylpropyl GSL in fruits, and additionally Trp-derived indol-3-ylmethyl GSL and 4-hydroxyindol-3-ylmethyl GSL in immature fruits. Several other GSLs were searched for and conclusively not found above the limit of detection.

The phytochemical investigation of the stem barks of Voacanga africana resulted in the isolation of fifteen known monoterpenoid indole alkaloids (1–15). The structures of the alkaloids were determined by comparison of their physical and spectroscopic data with those reported in literature. Twelve of these metabolites (4–15) were previously unreported within the genus Voacanga, thus they can serve as chemotaxonomic markers for V. africana to differentiate between V. africana from other species of the genus Voacanga. The alkaloids 3-oxoconopharyngine (6), ervahainanmine (10), crassanine (14) and conolobine A (15) hold the potential to serve as chemical markers for distinguishing V. africana from other family species. Furthermore, compounds 3, 6, 10, 12 showed potential antimicrobial activities against Candida albicans and Bacillus subtilis with MIC values of 6.25–12.50 μg/mL.

The purpose of this study is to identify the most productive cenopopulations (CP) of the rare species Rhodiola rosea based on the accumulation of biologically active compounds in the rhizomes in 14 CP from different ecological and geographical conditions of Altai Mountains. The composition and content of 11 components, including salidroside, tyrosol, (+)-catechin, epigallocatechin gallate, rosarin, rosavin, rosin, cinnamyl alcohol, rhodiosin, and rhodionin, were determined by HPLC analysis. The composition of phenolic compounds (PC) in the studied CPs of R. rosea was stable. The amounts of each of the 11 components of the PC and groups of compounds were different in the CPs from different ecological and geographical conditions. The highest and lowest levels of phenylpropanoids (PP) were found in individuals from the Ust-Kan region. These are CP1, from the Baschelaksky ridge, 2000 m above sea level (masl), and CP7 in the Talkash River valley, 1200 m above sea level (4613.1 ± 170.1 and 1362.0 ± 57.0 mg/100 g, respectively). The highest content of PP was found in the samples from seven CPs. Of these, 60% grew in the milder climatic conditions (Ust-Kan region). In terms of individual variability in PC content in two model CPs of R. rosea, a significantly higher content of most PC groups was found in the representatives from more stressful high-mountain conditions (2000 masl) in alpine zone, compared with the same indicators in plants growing at lower altitude in forest zone (1500 masl) (classification of N.I. Makunina, 2016). Selection of the most productive forms of this valuable medicinal species would allow for their in vitro introduction and micropropagation into the culture.

Phytochemical studies on the fruits of Illicium verum Hook. f., also known as star anise (Magnoliaceae), resulted in the isolation of thirty-five compounds, including ten phenylpropanoids (1–10), eight phenolic glycosides (11–18), five benzoic acids (19–23), four flavonoids (24–27), four lignans (28–31), three organic acids (32–34), and one monoterpenoid (35). The structures of these metabolites were determined through NMR spectroscopy analysis and comparison with existing literature. This is the first confirmation of the presence of eight compounds (1, 4–7, 13, 34 and 35) isolated from the family Magnoliaceae, one compound (11) from the genus Illicium, and three compounds (12, 28, 30) from I. verum. Furthermore, the taxonomic significance of these compounds was discussed.

Continual phytochemical investigation on the whole plants of Chloranthus henryi Hemsl afforded fourteen compounds (1–14), including eight sesquiterpene monomers (1–8), four sesquiterpene dimers (9–12), a diterpene (13), and a simple coumarin (14). The structures of these compounds were assigned by means of spectroscopic techniques and ECD calculations. Compounds 1a and 1b are a pair of cadinane-type sesquiterpene enantiomers, while compounds 3–7 and 11–14 are isolated from C. henryi for the first time. Moreover, the chemotaxonomic significance corresponding to the aforementioned compounds was investigated.

The present study involves the phytochemical analysis and assessing potential synergies among essential oils (EOs) against pests. The EOs were obtained by hydrodistillation from the aerial part (ASAO) and the root part (ASRO) of Artimisia scoparia, and from the aerial part of Centratherum punctatum (CPAO). The EOs yield ranged from 0.5 to 0.1% (v/w). The GC-MS analysis revealed the presence of 35, 43, and 49 compounds, constituting 99.2%, 98.34%, and 99.93% in ASAO, ASRO, and CPAO, respectively. Capillene was identified as the dominant compound both in ASAO and ASRO, but in variable amounts. Caryophyllene oxide (36.4%) was identified as the major component of CPAO. Pure EOs were blended in binary and ternary mixtures at ratios to analyze their synergistic effect against pests. The nematicidal activity (percent mortality and egg hatchability against Meloidogyne incognita at different concentrations was evaluated and the ternary mixture (ASAO + ASRO + CPAO) was found to be most effective at 1 μL/mL with 55.67 ± 1.41% larval immobility at 96 h of exposure. The antifeedant activity of pure and blended EOs was examined against Spodoptera litura using the leaf-dip method. Individually ASAO was most effective with 66.91% feeding inhibition, however the ternary combination showed 58.03% feeding inhibition. Moreover, molecular docking of selected volatiles (≥4% area) from the tested samples was carried out to analyze the interactions with target protein; acetylcholinesterase (AChE) and glutathione S-transferases (GST-1) and the ligands interacted favourably with the target proteins. The blending of EOs resulted in synergistic effects, enhancing their efficacy. Data acquired highlighted that A. scoparia and C. punctatum essential oils could be natural alternatives for nematode control and pest control in agriculture.

A strain of Penicillium chrysogenum, isolated from a volcanic area, was subjected to chemical analysis, leading to the isolation of fifteen compounds. Six compounds were isolated for the first time from this species, including the benzophenone derivative 1, pencillixanthone A (5), a pair of trichodimerol derivatives (7, 8), 4-epipenicillone (9), and the small pyrone 14. Several of the compounds were tested for antimicrobial properties; among them, the secalonic acid derivative (5) had significant antibacterial activity against five test strains, while the trichodimerol derivatives (8 and 9) and the anthranilate derivative 15 were reported to be active against four strains (S. aureus, S. mutans, P. fluorescens, M. catarrhalis) for the first time. In addition, this is the first time that haenamindole's antibacterial activity has been reported. The chemotaxonomic significance of the isolated compounds is discussed.