Sesquiterpene Glycosides from Flowers of Yucca gloriosa

Isolation of natural compounds from Phlomis stewartii showing α-glucosidase inhibitory activity

Two orphan flavonoids containing an oxepin structure in ring A and named as Primcortusin (1) and 3'-OH-Primcortusin (2) were isolated from leaf exudates of Primula cortusoides, while P. glutinosa exudates yielded two dihydrochalcone derivatives (3,4). These novel structures have not been detected in other species of Primula so far. Chemical structures were elucidated by 2D NMR and mas spectrometry. The nature of compounds 1 and 2 is discussed, and ideas about their possible origin and that of unsubstituted flavone and other irregular substituted Primula flavones are presented.

Considering the richness of heterocyclic chemistry, and the diversity of applications it possesses, in the present work we were interested in preparing new polyfunctional α,α-diaminodiesters derived from glycine, via the N-alkylation reaction of methyl 2-azido-2-benzamidoacetate with a series of heterocyclic and non-heterocyclic carboxylic aminoesters, using different bases. The structures of the synthesized molecules were characterized by 1D and 2D NMR spectroscopy, mass spectrometry (MS-ESI) and elemental analysis. Two compounds from this series were isolated as single crystals and their chemical structures were determined by X-ray diffraction. The antioxidant effect of the synthesized compounds was tested in vitro using the free radical scavenging power (DPPH) and reducing power (FRAP) tests. The results show that the different extracts tested have a relatively high antioxidant power compared to the positive control considered, especially for the compound methyl 2-benzamido-2-(2-methoxy-2-oxo-1-phenylethyl)amino)acetate, which showed a very strong antiradical power and reducing power.

Lysaketotriol (1) and lysaketodiol (2), along with two previously known polyhydroxylated steroidal sulfates (3, 4), were isolated from the ethanolic extract of ambulakrums separated from the arms of the starfish Lysastrosoma anthosticta (Sea of Japan). The chemical structures have been elucidated using 1D and 2D NMR spectroscopy (1H, 13C, DEPT, COSY-45, HSQC and HMBC) and mass spectrometry. Compound 1 produced moderate stimulation of lysosomal activity in mouse splenocytes and compounds 1-2 showed immunomodulatory activity.

Terphenyl derivatives and drimane – Phathalide/isoindolinones from Hypoxylon fendleri BCC32408

Antibacterial, antitubercular, antimalarial and cytotoxic substances from the endophytic Streptomyces sp. TBRC7642

Three sesquiterpene glycosides, i.e., nerolidol derivatives, and steroidal glycosides of the 3-furostanol and 1-spirostanol series, one of which was new and characterized as (25R)-26-O-β-D-Glcp-5α-furostan-3β,22α,26-triol 3-O-β-D-Xylp-(1→3)-[O-β-D-Glcp-(1→3)-O-β-D-Glcp-(1→2)]-O-β-D-Glcp-(1→4)-O-β- D-Galp, were isolated from flowers of Yucca elephantipes Regel cultivated in Georgia. The structures of the glycosides were elucidated using one- and two-dimensional NMR (1H, 13C, HSQC, HMBC, COSY) and mass spectrometry (ESI-MS).

Boophone disticha (Amaryllidaceae) is widely used in traditional medicine in southern Africa. Several alkaloids, volatile oils and fatty acids have been isolated from the plant. However, there has been no literature report of a triterpene from B. disticha. Cycloeucalenol, a cycloartane triterpene, together with its regio-isomer, was isolated from the ethyl acetate extract of the bulbs using column chromatography and preparative thin layer chromatography. Structural elucidation was carried out using 1D and 2D NMR and mass spectroscopy. The MTT and neutral red assays were used to assess the cytotoxicity of the compound in human neuroblastoma (SH-SY5Y) cells. The compound was obtained as a mixture of two regio-isomers, which were separated for the first time by chromatographic optimization. Integration of the 1H NMR spectrum showed that cycloeucalenol and its regio-isomer were present in a ratio of 1.04:1. A dose-dependent decrease in cell viability was observed using both cytotoxicity assays. IC51 values of 173.0 +/- 5.1 microM and 223.0 +/- 6.4 microM were obtained for the MTT and neutral red assays, respectively, indicative of the low toxicity of the compound. This work describes for the first time, the presence of triterpene compounds from the genus Boophone.

Anxiolytic effect of a novel 9,10-dihydrophenanthrene, juncuenin H, is associated with metabolic changes in cortical serotonin/dopamine levels in mice

Endophytic bacteria boost host plant defense and growth by producing vital compounds. In the current study, a bacterial strain was isolated from the Boswellia sacra plant and identified as Bacillus subtilis strain EP1 (accession number: MT256301) through 16S RNA gene sequencing. From the identified bacteria, four compounds-1 (4-(4-cinnamoyloxy)phenyl)butanoic acid), 2 (cyclo-(L-Pro-D-Tyr)), 3 (cyclo-(L-Val-L-Phe)), and 4 (cyclo-(L-Pro-L-Val))-were isolated and characterized by 1D and 2D NMR and mass spectroscopy. Moreover, antibacterial activity and beta-lactam-producing gene inhibition (δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine synthetase (ACVS) and aminoadipate aminotransferase (AADAT)) assays were performed. Significant antibacterial activity was observed against the human pathogenic bacterial strains (E. coli) by compound 4 with a 13 ± 0.7 mm zone of inhibition (ZOI), followed by compound 1 having an 11 ± 0.7 mm ZOI. In contrast, the least antibacterial activity among the tested samples was offered by compound 2 with a 10 ± 0.9 mm ZOI compared to the standard (26 ± 1.2 mm). Similarly, the molecular analysis of beta-lactam inhibition determined that compounds 3 and 4 inhibited the two genes (2- to 4-fold) in the beta-lactam biosynthesis (ACVS and AADAT) pathway. From these results, it can be concluded that future research on these compounds could lead to the inhibition of antibiotic-resistant pathogenic bacterial strains.

Phenolic acid glycosides from Parmentiera cereifera Seem. (Candle tree)

New hetaryl- and alkylidenerhodanine derivatives 3a–d, 3e, and 4a–d were prepared from heterocyclic aldehydes 1a–d or acetaldehyde 1e. The treatment of several rhodanine derivatives 3a–d and 3e with piperidine or morpholine in THF under reflux, afforded (Z)-5-(hetarylmethylidene)-2-(piperidin-1-yl)thiazol-4(5H)-ones and 2-morpholinothiazol-4(5H)-ones 5a–d, 6a–d, and (Z)-5-ethylidene-2-morpholinothiazol-4(5H)-one (5e), respectively, in good yields. Structures of all compounds were determined by IR, 1D and 2D NMR and mass spectrometry. Several of these compounds were screened by the U.S. National Cancer Institute (NCI) to assess their antitumor activity against 60 different human tumor cell lines. Compound 3c showed high activity against HOP-92 (Non-Small Cell Lung Cancer), which was the most sensitive cell line, with GI50 = 0.62 μM and LC50 > 100 μM from the in vitro assays. In vitro antifungal activity of these compounds was also determined against 10 fungal strains. Compound 3e showed activity against all fungal strains tested, but showed high activity against Saccharomyces cerevisiae (MIC 3.9 μg/mL).

Structural and chromatic characterization of a new Malvidin 3-glucoside–vanillyl–catechin pigment

ABSTRACTBackground: Millettia aboensis (Hook. F.) Baker (Fabaceae) is popular in ethnomedicine for its acclaimed efficacy in a number of disease conditions. This study evaluated the immunomodulatory effect of the leaf extract as a possible mechanism of its ethnomedicinal uses.Methods: Humoral and cellular immune responses of Balb/c mice to tetanus toxoid and cyclophosphamide, respectively, were used to monitor immunomodulatory activities of the ethanol leaf extract and fractions of M. aboensis at 200, 300 and 400 mg/kg. Active (butanol) fraction of the extract was subjected to chromatographic purifications to isolate the active compound and the structure elucidated by a combination of 1D and 2D NMR and mass spectrometry. Stimulation of specific T-lymphocytes using intracellular cytokine staining technique was used to evaluate immune-enhancing activity of the isolated compound.Results: The extract and fractions evoked increase in both humoral and cellular immunity. At 400 mg/kg of butanol fraction, the normalized mean secondary production of IgG1 and IgG2a antibodies were 9.0 and 7.7, respectively. Serum cytokine production by butanol fraction following secondary challenge with tetanus toxoid showed that IL-12, IL-17A and IFN-γ were expressed by 48.14, 41.37 and 38.22%, respectively. Structural elucidation of the active compound revealed presence of isomeric mixtures of quercetin-3-O-rutinoside and quercetin-3-O-robinobioside (Compound 1a/b). Compound 1a/b exhibited in vitro upregulation of specific CD4+ T-lymphocytes that were largely IFNγ releasing with up to 43.7% stimulation at 6.25 μg/mL compared to the baseline effect in DMSO vehicle control group.Conclusion: M. aboensis expressed strong immune-enhancing properties, which may explain its ethnopharmacological use in disease management.

From the leaves and the roots of Gundelia tournefortii L. (Asteraceae), an edible plant collected in Lebanon, ten oleanane-type glycosides were extracted, purified by various chromatographic methods, and identified by spectroscopic analysis as eight previously undescribed saponins 1-5 and 7-9 and two known ones 6 and 10. Their aglycons possess unusual, oxygenated skeletons in position 29 or 30. Their structures were assigned by spectroscopic analysis mainly 2D NMR (COSY, TOCSY, ROESY, HSQC, HMBC) and mass spectrometry. Some selected saponins were tested for their stimulating activity on the sweet taste receptor.