Molecular networking-driven isolation of 8'-Glycosylated biscoumarins from Cruciata articulata.

A molecular networking-guided phytochemical investigation of Cruciata articulata led to the isolation of five unreported biscoumarins, four of which were characterized by a shared 6-methoxy-7,8'-dihydroxy-3,7'-biscoumarin aglycone. These were isolated alongside two known coumarin glycosides, daphnetin-8-O-ß-D-glucoside and 6'-acetoxy-daphnetin-8-O-ß-D-glucoside. Their structures were elucidated by extensive 1D and 2D NMR experiments, in combination with chemical transformation and MS/MS fragmentation analysis. Four of the biscoumarins were glycosylated at the 8' position: these are the first examples of this substitution pattern to be described in nature. All compounds were tested for cytotoxic, antimicrobial, anti-inflammatory, and α-glucosidase inhibitory properties, but did not display significant activity.

Cruciasides C-G, monoterpenoid glycosides from Cruciata articulata.

Cruciata articulata (L.) Ehrend. is a herbaceous species distributed in parts of Western Asia and the Mediterranean region. While research on other species in the Cruciata genus has revealed the presence of a range of flavonoids and terpenoids, few such studies have been conducted on C. articulata. Thus, in the current study, a phytochemical investigation of C. articulata was carried out. Molecular networking identified a large cluster of compounds sharing distinctive MS-MS fragmentation patterns that were targeted for isolation, leading to the isolation of five undescribed monoterpenoid glycosides, cruciasides C-G, along with two known monoterpenoid glycosides. The structures of these compounds were elucidated by using chemical and spectroscopic analyses, including 1D and 2D NMR, and MS-MS fragmentation. Structures for the ions observed in the MS-MS were proposed, and based on these fragmentation patterns, structures for several of the minor components observed in the molecular network were also proposed. All isolated compounds were tested for cytotoxic, anti-inflammatory, antimicrobial, and α-glucosidase inhibitory properties, but did not display any activity.

Feruloyl sucrose derivatives from the root of Xerophyllum tenax.

A phytochemical investigation of the roots of Xerophyllum tenax led to the isolation of three undescribed feruloyl sucrose derivatives along with two known feruloyl sucrose derivatives, heloniosides A and B. This is the first report of their occurrence in the genus Xerophyllum and the family Melanthiaceae. The structures of these compounds were elucidated on the basis of chemical and spectroscopic analysis including 1D and 2D NMR and analysis of MS-MS fragmentation.

Potential anti-neuroblastoma agents from Juniperus oblonga.

Neuroblastoma (NB) is a neuroendocrine tumor derived from neural crest cells. Approximately 90% of cases occur in children less than 5 years old. The amplification of MYCN correlates with high-risk neuroblastoma and patients with MYCN amplified showed poorer prognosis than those without MYCN amplification. In this study, three compounds isolated from Juniperus oblonga showed anti-proliferative activity against NB cell lines with and without tetracycline inducible MYCN over-expression which were identified as (-)-deoxypodophyllotoxin (1), (-)-matairesinol (2) and (+)-isocupressic acid (3). The effects of compounds 2 and 3 in NB cells included a decrease in NB cell viability and induction of apoptosis. Compound 1 was more effective in NB cells over-expressing MycN. Compound 1 also showed almost 2-fold induction of intracellular free calcium levels in M2(+) cells, which may indicate a different mechanism of action for this compound. Cytotoxicity studies against the human embryonic kidney cell (HEK-293) showed compounds 1, 2 and 3 were ineffective in the non-cancer cells at concentrations approximating their IC50 against the NB cell lines. These results may lead to safer and more effective treatment options for NB patients especially for those with high-risk NB.

Unusual Flavones from Primula macrocalyx as Inhibitors of OAT1 and OAT3 and as Antifungal Agents against Candida rugosa.

A bioactivity guided program exploring the interaction of phytochemicals in the entire plant Primula macrocalyx with the organic anion transporters (OAT1 and OAT3) and microorganisms led to the elucidation of ten known flavones (1-4, 6-10, 12) and two previously undescribed flavones (5, 11). The structures of the compounds were determined by extensive analysis of spectroscopic data, as well as by comparison with data from previous reports. Two known flavones (9, 12) are reported for the first time from the family Primulaceae. All compounds were evaluated for inhibition of OAT1 and OAT3. Six flavones (2, 3, 6-8, 12) showed potent inhibitory activity on OAT1, while seven flavones (2, 3, 6-9, 12) showed marked inhibitory activity on OAT3, with IC50 ≤ 10.0 µM. Antimicrobial activities of crude fractions against sixteen microorganisms were tested to give a target yeast strain Candida rugosa for further evaluation of MICs on the isolates. Three flavones (7, 8, 12) showed marked antifungal activity with MIC < 2.0 µM. To our knowledge, this study is the first to evaluate these flavones as inhibitors of the OAT1 and OAT3, and as antifungal agents.

Labdane and Abietane Diterpenoids from Juniperus oblonga and Their Cytotoxic Activity.

A phytochemical investigation of the whole plant of Juniperus oblonga led to the isolationof one previously undescribed labdane diterpenoid, (4R,5S,9S,10R)-13-des-ethyl-13-oxolabda-8(17),11E-dien-19-oic acid (1), together with nine known diterpenoids (2-3, 6-12), two lignans (4, 5),and a coumarin (13). The structures of all the compounds were elucidated on the basis ofspectrometric data, primarily one-dimensional (1D)- and two-dimensional (2D)-NMR and massspectrometry. Electronic circular dichroism (ECD) calculations determined the absoluteconfiguration of 1. In addition, the isolated compounds were evaluated for their cytotoxic activityagainst three human tumor cell lines (HepG2, MCF-7, and HeLa). 6,12-Dihydroxyabieta-5,8,11,13-tetraen-7-one (6) showed moderate cytotoxicity against all three cell lines with IC50 values rangingfrom 24.41 µM to 58.39 µM and trilobinone (10) showed weaker activity with IC50 values rangingfrom 56.93 µM to 79.98 µM. None of the isolated diterpenoids have been previously reported fromJuniperus oblonga, and five compounds are here reported from the genus Juniperus for the first time.

Biflavonoids from Juniperus oblonga inhibit organic anion transporter 3.

Organic anion transporters (OATs in humans, Oats in rodents) play an important role in the distribution and excretion of numerous endogenous metabolic products and exogenous organic anions, including a host of widely prescribed drugs. Their ligand recognition is also important for drug therapy and development. In this study, the n-butanol and dichloromethane soluble fractions of Juniperus oblonga were found to inhibit OAT3 in vitro and three biflavonoids were found to be responsible for this activity. One of these compounds, amentoflavone exhibited stronger inhibition than probenecid, a known strong inhibitor of OAT3. Biological characterization of amentoflavone in vivo also showed inhibition of Oat3. Preliminary observations of structure-activity relationships suggest that the biflavonoids are more potent inhibitors of this transporter than their corresponding monomer, and that methylation of even a single hydroxyl group results in a substantial decrease in activity. This greater potency of the biflavonoids may indicate the need for a more in-depth investigation of the distribution of biflavonoids in plants used as foodstuffs and herbal medicines, due to their potential for causing interactions with OAT3 substrate drugs.

Isoflavones from Camphorosma lessingii Inhibit the Organic Anion Transporters OAT1 and OAT3.

Phytochemical investigation of Camphorosma lessingii has resulted in the isolation of four previously unreported isoflavones (1: -4: ) and eight known compounds (5: -12: ). Nine of these compounds (1: -6, 8: -10: ) are reported for the first time from members of the family Amaranthaceae. The structures of all isolated compounds were determined by spectroscopic methods, primarily one-dimensional and two-dimensional nuclear magnetic resonance and mass spectrometry. The absolute configuration of 6: was confirmed by circular dichroism. Inhibition of the organic anion transporters, OAT1 and OAT3, by the isolated compounds was evaluated. Among them, 7, 2'-dihydroxy- 6,8-dimethoxyisoflavone (1: ), 2'-hydroxy-6,7,8-trimethoxyisoflavone (2: ), 6,2'-dihydroxy-7,8-dimethoxyisoflavone (3: ), and 7-methoxyflavone (5: ) showed a significant inhibitory effect on 6-carboxyfluorescein uptake mediated by OAT1 and OAT3.

Scrophularia orientalis extract induces calcium signaling and apoptosis in neuroblastoma cells.

Effective neuroblastoma (NB) treatments are still limited despite treatment options available today. Therefore, this study attempted to identify novel plant extracts that have anticancer effects. Cytotoxicity and increased intracellular calcium levels were determined using the Sulforhodamine B (SRB) assay and Fluo4-AM (acetoxymethyl) staining and fluorescence microscopy in NB cells in order to screen a library of plant extracts. The current study examined the anticancer effects of a dichloromethane extract from Scrophularia orientalis L. (Scrophulariaceae), a plant that has been used in Traditional Chinese Medicine. This extract contained highly potent agents that significantly reduced cell survival and increased calcium levels in NB cells. Further analysis revealed that cell death induced by this extract was associated with intracellular calcium release, opening of the MPTP, caspase 3- and PARP-cleavage suggesting that this extract induced aberrant calcium signaling that resulted in apoptosis via the mitochondrial pathway. Therefore, agents from Scrophularia orientalis may have the potential to lead to new chemo-therapeutic anticancer drugs. Furthermore, targeting intracellular calcium signaling may be a novel strategy to develop more effective treatments for NB.

Antioxidant capacities of ten edible North American plants.

The EtOAc extract obtained from ten edible North American plants, Acorus calamus, Clintonia borealis, Gaultheria shallon, Juniperus osteosperma, Opuntia polyacantha, Prunus americana, Prunus virginiana, Sambucus cerulea, Sorbus americana and Vaccinium parvifolium, were tested in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay. High antioxidant activity was obtained from the extracts of three fruits, Gaultheria shallon, Sambucus cerulea and Prunus americana and one extracted rhizome, Acorus calamus. Catechin and epicatechin, potent polyphenolic antioxidants, were identified in the EtOAc extracts of Gaultheria shallon and Sambucus cerulea by reversed-phase thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (HPLC).