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Compositions of the Volatile Oils of Citrus Macroptera and C. Maxima
2012
The essential oils obtained by hydrodistillation from the fresh peels of Citrus macroptera Montr. and C maxima(Burm.) Merr. were analyzed by GC and GC/MS. The yields of oil ranged from 0.53% in C macroptera to 0.13% in C maxima cultivar (white). Forty-seven compounds were identified in the oils with limonene (55.3-80.0%), dodecyl acrylate (2.2-8.0%), geranial (0.4-3.5%), trans-linalool oxide (1.0-2.8%), α-terpineol (0.7-2.3%), linalool (0.7-1.5%) and cis- linalool oxide (0.5-1.4%) identified as major compounds. The oil of C. macroptera contained limonene (55.3%), β-caryophyllene (4.7%) and geranial (3.5%) as main compounds. Similarly, oils from two C maxima(pink and white) cultivars were r…
Secondary metabolites from the roots of Paronychia chionaea
2011
Two novel secondary metabolites, compounds (1–2) were isolated from the roots of Paronychia chionaea. On the basis of spectroscopic data including 1D and 2D NMR experiments (COSY, TOCSY, HSQC, and HMBC), and mass spectroscopy, their structures were established as 6- C-[α-L-arabinopyranosyl-(1→2)-β-D-glucopyranosyl]-7- O-[β-D-glucopyranosyl]-luteolin 3′-methyl ether (1), and 2-(methoxy)-2-(3,5-dimethoxy 4-hydroxyphenyl)-ethane-1,2-diol 1- O-β-D-glucopyranoside (2).
Steroidal saponins from Dracaena marginata
2013
Three new steroidal saponins and ten known ones were isolated from the bark of Dracaena marginata, along with two known steroidal saponins from the roots. Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments and mass spectrometry as (25R)-26-(beta-D-glucopyranosyloxy)3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (1), (25R)-26-(beta-D-glucopyranosyloxy)-3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (2), and (25S)-3beta-hydroxyspirost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L…
Left, Right, or Both? On the Configuration of the Phenanthroindolizidine Alkaloid Tylophorine from Tylophora indica
2013
The alkaloid (-)-tylophorine was isolated from a sample of Tylophora indica, and the crude extract was analyzed by HPLC/MS(n) and chiral HPLC/MS. While the literature states that the naturally occurring form of this alkaloid is the R-enantiomer and that its S-antipode is usually not found in nature, we confirmed the hypothesis of Govindachari and Nagarajan that natural levorotatory tylophorine is indeed a nearly racemic mixture with a slight excess of the R-enantiomer.
Aaptamine Derivatives from the Indonesian Sponge Aaptos suberitoides
2013
Four new aaptamine derivatives (1-4) along with aaptamine (5) and three related compounds (6-8) were isolated from the ethanol extract of the sponge Aaptos suberitoides collected in Indonesia. The structures of the new compounds were unambiguously determined by one- and two-dimensional NMR and by HRESIMS measurements. Compounds 3, 5, and 6 showed cytotoxic activity against the murine lymphoma L5178Y cell line, with IC(50) values ranging from 0.9 to 8.3 μM.
Ircinal E, a New Manzamine Derivative from the Indonesian Marine Sponge Acanthostrongylophora ingens
2015
Chemical investigation of the MeOH extract of the sponge Acanthostrongylophora ingens afforded the new manzamine derivative ircinal E (1), in addition to six known metabolites (2–7). The structure of the new compound was unequivocally elucidated using one- and two-dimensional NMR spectroscopy, as well as high-resolution mass spectrometry. Compounds 1–6 exhibited strong to moderate cytotoxicity against the murine lymphoma L5178Y cell line with IC50 values ranging from 2.8 to 21.7 μM.
Acid Rearrangment of Epoxy-germacranolides and Absolute Configuration of 1β,10α-Epoxy-salonitenolide
2010
The acid-catalyzed cyclization of mono epoxides of cnicin acetonide (3) was investigated. Several 6,12-eudesmanolides were obtained, and their stereochemistry established by extensive spectroscopic analyses. Chemical correlations also led to the assignment of the absolute configuration of 1β,10α-epoxy-salonitenolide (13), a previously isolated natural product. The cytotoxic activities of some compounds were determined against A549 and MCF-7 tumor cell lines. The esterified germacranolides 2–6 were selectively cytotoxic against the MCF-7 breast cancer cell line.
Chemical Composition of the Essential Oils of Three Species of Apiaceae Growing Wild in Sicily: Bonannia graeca, Eryngium maritimum and Opopanax chir…
2013
In the present study the chemical composition of the essential oils from aerial parts of Bonannia graeca (L.) Halácsy and Opopanax chironium (L.) Kock, and from aerial parts and roots of Eryngium maritimum L. was evaluated by GC and GC-MS. α-Pinene (15.2%) and β-pinene were recognized as the main constituents of B. graeca, whereas the aerial parts of O. chironium contained mainly the diterpene cembrene and the coumarin angelicin. In both aerial parts and roots of E. maritimum germacrene D (10.4% and 15.9%, respectively) and 2,4,5-trimethylbenzaldehyde (8.3% and 6.7%) were the most abundant components.
Crotofolane Diterpenoids and Other Constituents Isolated from Croton kilwae
2023
Six new crotofolane diterpenoids (1-6) and 13 known compounds (7-19) were isolated from the MeOH- CH2Cl2 (1:1, v/v) extracts of the leaves and stem bark of Croton kilwae. The structures of the new compounds were elucidated by extensive analysis of spectroscopic and mass spectrometric data. The structure of crotokilwaepoxide A (1) was confirmed by single -crystal X-ray diffraction, allowing for the determination of its absolute configuration. The crude extracts and the isolated compounds were investigated for antiviral activity against respiratory syncytial virus (RSV) and human rhinovirus type-2 (HRV-2) in HEp-2 and HeLa cells, respectively, for antibacterial activity against the Gram-posit…
Modified ent-Abietane Diterpenoids from the Leaves of Suregada zanzibariensis
2022
The leaf extract of Suregada zanzibariensis gave two new modified ent-abietane diterpenoids, zanzibariolides A (1) and B (2), and two known triterpenoids, simiarenol (3) and β-amyrin (4). The structures of the isolated compounds were elucidated based on NMR and MS data analysis. Single-crystal X-ray diffraction was used to establish the absolute configurations of compounds 1 and 2. The crude leaf extract inhibited the infectivity of herpes simplex virus 2 (HSV-2, IC50 11.5 μg/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC50 52 μg/mL. The isolated compounds 1–3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at ≥100 μM. p…