A new acylated flavonol triglycoside and evaluation of the antioxidant activity of Astragalus armatus subsp. numidicus (Murb.) Emb. & Maire

A new acylated flavonol triglycoside, quercetin-3-O-(5'-p-hydroxybenzoyl)-β-D-apiofuranosyl-(1→2)[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranoside (1), was isolated from the aerial parts of Astragalus armatus subsp. numidicus (Murb.) Emb. & Maire as well as ten known compounds, one phenolic compound, one flavonol-aglycone and eight flavonol-glycosides distributed into two monoglycosides, three diglycosides and three triosides. Their structures were mainly determined by 1D- and 2D-NMR experiments (1H,13C, COSY, HSQC, HMBC). The chloroform, ethyl acetate, n-butanol and hydroethanol extracts were tested for their antioxidant activity using five methods (DPPH, ABTS, Reducing power, CUPRAC and Phenanthroline). The ethyl acetate extract was the most active in CUPRAC (A0.5: 50.28 ± 2.16 µg/mL), ABTS (IC50: 49.73 ± 1.55 µg/mL) and Reducing power (A0.5: 58.13 ± 4.35 µg/mL) assays, whereas the hydroethanol and n-BuOH exhibited the highest activity in the Phenanthroline assay (A0.5: 9.93 ± 0.16) and (A0.5: 10.27 ± 0.44 µg/mL), respectively.

Triterpene saponins from Silene gallica collected in North-Eastern Algeria

Eleven previously undescribed triterpene saponins, named silenegallisaponin A-K (1-11), were isolated from the aerial parts of Silene gallica L. Their structures were elucidated by analysis of 1D and 2D-NMR spectroscopic data and mass spectrometry (HR-ESI-MS). The saponins comprised caulophyllogenin, echinocystic acid, or quillaic acid substituted at C-3 by a β-d-glucuronic acid or β-d-galactopyranosyl-(1 → 3)-β-d-glucuronopyranoside and at C-28 by a β-d-fucopyranose substituted at C-2 by a β-d-glucose and at C-3 by a β-d-glucose or a β-d-quinovose.

Triterpenes from Salvia argentea var. aurasiaca and their antibacterial and cytotoxic activities

Five undescribed ursane-type triterpenes, identified as 1β,3β,15α-trihydroxy-urs-9(11)-12-diene (1), 1β,3β,15α,28-tetrahydroxy-urs-9(11),12-diene (2), 1β,3β-dihydroxy-urs-9(11),12-dien-28-al (3), 1β,3β,7β,15α,28-pentahydroxy-urs-12-ene (4), and 1β,3β,15α-trihydroxy-urs-11-en-28-al (5), together with five known compounds (6-10), were isolated from the acetone extract of the dried aerial parts of Salvia argentea L. var. aurasiaca (Pomel) Batt. et Trab. (Lamiaceae). Structures were elucidated on the basis of extensive spectroscopic analysis including HR-ESI-MS, 1D- and 2D-NMR techniques and comparison with literature data. The antibacterial evaluation of compounds 1-10 of the acetone extract of the dried aerial parts, in addition to nine compounds (11-19) previously isolated from the extract of the fresh aerial parts, by bioautography on Staphylococcus aureus followed by the determination of MIC values of active compounds by serial dilution technique against five bacteria, revealed that two compounds have an antibacterial effect comparable to antibiotics. The cytotoxic activity evaluation of compounds 1-19 showed that Six compounds exhibited an antiproliferative activity against K562 and HT1080 cells with IC₅₀ values ranging from 30.25 to 70.32 μM.

Antiangiogenic Activity of Compounds Isolated from Anarrhinum pedatum

Ten new iridoid glycosides (1-10) and two new monoterpenoids (11 and 12), together with nine known compounds (13-21), were isolated from the n-butanol extract of the aerial parts of Anarrhinum pedatum. The structural characterization of all compounds was performed by spectroscopic analysis, including 1D and 2D NMR and HRESIMS experiments. The isolates were assayed for their antiangiogenic activity by two in vivo models, using zebrafish embryos and chicken chorioallantoic membranes (CAMs). The results showed that among the new compounds 6'- O-menthiafoloylmussaenosidic acid-11-(5- O-β-d-fructopyranosyl) ester (9) exhibited the most potent antiangiogenic activity in both the zebrafish embryos and CAM assays, reducing the growth of blood vessels. Antiangiogenic effects were also observed for the known compounds 6- O-nerol-8-oyl-antirrinoside (13), antirrinoside (14), 6- O- trans- and cis- p-coumaroyl antirrinoside (15), and (6 S)-2 E-2,6-dimethyl-6-hydroxyocta-2,7-dienoic acid β-glucopyranosyl ester (18).

New Phenylethanoid Glycosides from Cistanche phelypaea and Their Activity as Inhibitors of Monoacylglycerol Lipase (MAGL)

Four new phenylethanoid glycosides (1: -4: ), 1-β-p-hydroxyphenyl-ethyl-2-O-acetyl-3,6-di-α-l-rhamnopyranosyl-β-d-glucopyranoside (1: ), 1-β-p-hydroxyphenyl-ethyl-3,6-O-di-α-l-rhamnopyranosyl-β-d-glucopyranoside (2: ), 1-β-p-hydroxyphenyl-ethyl-2-O-acetyl-3,6-di-α-l-rhamnopyranosyl-4-p-coumaroyl-β-d-glucopyranoside (3: ), and 1-β-p-hydroxyphenyl-ethyl-3,6-di-α-l-rhamnopyranosyl-4-p-coumaroyl-β-d-glucopyranoside (4: ), together with three known compounds, were isolated from the n-butanol extract of Cistanche phelypaea aerial parts. The structural characterization of all compounds was performed by spectroscopic analyses, including 1D and 2D NMR, and HRESIMS experiments. The isolated compounds were assayed for their inhibitory activity on two enzymes involved in the peculiar glycolytic or lipidic metabolism of cancer cells, human lactate dehydrogenase (LDH), and monoacylglycerol lipase (MAGL), respectively. All the compounds showed negligible activity on LDH, whereas some of them displayed a certain inhibition activity on MAGL. In particular, compound 1: was the most active on MAGL, showing an IC₅₀ value of 88.0 µM, and modeling studies rationalized the supposed binding mode of 1: in the MAGL active site.

Flavonoids, cytotoxic, antioxidant and antibacterial activities of Evax pygmaea

CONTEXT

Phytochemical study and biological potential of Evax pygmaea (L.) Brot. (Asteraceae) are reported for the first time.

OBJECTIVE

To identify the secondary metabolites of Evax pygmaea and to determine its antioxidant, antibacterial and cytotoxic activities.

MATERIALS AND METHODS

Dried aerial parts (1 kg) were macerated in 70% MeOH (5 L) during 72 h. The concentrated hydromethanolic extract was subjected to extractions with chloroform (3 × 300 mL), ethyl acetate (3 × 300 mL) and n-butanol (3 × 300 mL), successively. VLC of combined ethyl acetate (EAEP) and n-butanol (BEP) fractions was followed by column purifications. Antioxidant activity was investigated using DPPH, CUPRAC, and metal chelating, β-carotene/linoleic acid and ABTS assays. Agar method was used in the antibacterial study. Cytotoxic activity was determined by Brine shrimp lethality test in DMSO and ethanol, at varying concentrations (2, 1 and 0.2%) and (1, 0.2 and 0.1%) successively.

RESULTS

Quercetin (1), isorhamnetin 3-O-β-d-xyloside (2), isorhamnetin 3-O-β-d-glucoside (3), quercetin 3-O-β-d-glucoside (4), quercetin 7-O-β-D-glucoside (5), patuletin 3-O-β-d-glucoside (6) were isolated from for the first time from Evax genus. The EAEP was the most active in ABTS (IC₅₀: <3.125 μg/mL) assay whereas the BEEP exhibited the highest activity in the β-carotene/linoleic acid assay (IC₅₀: <3.125 μg/mL). The EAEP and BEP exhibited good antibacterial activity (MIC: 40-80 µg/mL). The plant did not show any toxicity (LD₅₀>80 µg/mL).

DISCUSSION AND CONCLUSIONS

Six flavonoids were isolated for the first time from Evax pygmaea which exhibited good antioxidant and antibacterial activities.

A new 2-alkylhydroquinone glucoside from Phagnalon saxatile (L.) Cass

A new 2-alkylhydroquinone glucoside, 1-O-β-d-glucopyranosyl-1,4-dihydroxy-2-((E) 2-oxo-3-butenyl)benzene (1), in addition to nine known compounds were isolated from the aerial parts of Phagnalon saxatile (L.) Cass. (Asteraceae). Their structures were identified based on spectroscopic methods including 1D and 2D NMR, mass spectrometry (HR-ESI-MS), UV spectral analyses and by comparison with literature data. The cytotoxic activity of three isolated compounds (1-3) was evaluated against fibrosarcoma (HT1080), human lung cancer (A549) and breast cancer (MCF7) cell lines.

Comparative composition of four essential oils of Oregano used in Algerian and Jordanian folk medicine

The essential oils obtained from Origanum glandulosum Desf., collected from two different localities of north-eastern Algeria, Constantine and Jijel, and from O. syriacum var. syriacum grown at El-Aghwar (northern Jordan) and El-Shubak (southern Jordan), were analyzed by GC-MS. p-Cymene (6.6% and 7.5%) and gamma-terpinene (13.4% and 14.5%) were found in O. glandulosum grown at Constantine and Jijel, respectively, in addition to the major components thymol (34.2%, 51.1%) and carvacrol (30.5%, 6.8%). The oil of O. syriacum L. var syriacum (Boiss.) Ietswaart from El-Shubak was mainly represented by thymol (51.8%) and carvacrol (34.4%), while the oil from El-Aghwar was a thymol-chemotype (72.4%), along with gamma-terpinene (7.8%) and p-cymene (5.4%).

Comparative Composition of Four Essential Oils of Oregano Used in Algerian and Jordanian Folk medicine

The essential oils obtained from Origanum glandulosum Desf., collected from two different localities of north-eastern Algeria, Constantine and Jijel, and from O. syriacum var. syriacum grown at El-Aghwar (northern Jordan) and El-Shubak (southern Jordan), were analyzed by GC-MS. p-Cymene (6.6% and 7.5%) and γ-terpinene (13.4% and 14.5%) were found in O. glandulosum grown at Constantine and Jijel, respectively, in addition to the major components thymol (34.2%, 51.1%) and carvacrol (30.5%, 6.8%). The oil of O. syriacum L. var syriacum (Boiss.) Ietswaart from El-Shubak was mainly represented by thymol (51.8%) and carvacrol (34.4%), while the oil from El-Aghwar was a thymol-chemotype (72.4%), along with γ-terpinene (7.8%) and p-cymene (5.4%).