Two New Triterpenes and Other Compounds from Mentha aquatica (Lamiaceae).

Two new triterpenoids, maquatic acid (1), a 2,3-seco-triterpene having an acetal in its A-ring, and 3-Ο-benzoyltormentic acid (2), were isolated from underground parts of Mentha aquatica, in addition to twelve known compounds, tormentic acid (3), 1-Ο-benzoylhyptadienic acid (4), 3-epi-ursolic acid (5), hyptadienic acid (6), 3-epi-maslinic acid (7), 3-epi-tormentic acid (8), ursolic acid (9), ß-sitosterol (10), oleanolic acid (11), pomolic acid (12), micromeric acid (13) and 21α-hydroxyursolic acid (14) from aerial and underground parts of the plant. Compounds 4-6, 8, 13 and 14 have been isolated from the genus Mentha for the first time.

Antioxidant, anticholinesterase and antibacterial activities of Stachys guyoniana and Mentha aquatica.

CONTEXT: Stachys guyoniana Noë ex. Batt. and Mentha aquatica L. are two Algerian Lamiaceae used in folk medicine. OBJECTIVE: To investigate their antioxidant, anticholinesterase and antibacterial activities. MATERIAL AND METHODS: n-Butanol (BESG), ethyl acetate (EESG) and chloroform (CESG) extracts of S. guyoniana and methanol (MEMA) and chloroform (CEMA) aerial part extracts of M. aquatica and methanol (MERMA) and acetone (AERMA) roots extracts of M. aquatica were evaluated for their antioxidant activity by the ß-carotene-linoleic acid, DPPH• and ABTS•+ scavenging, CUPRAC and metal chelating assays. The anticholinesterase activity was tested against AChE and BChE. The antibacterial activity was assessed by MICs determination against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella heidelberg, Klebsiella pneumoniae, Enterobacter aerogenes and Morganella morganii strains. RESULTS: In the ß-carotene test, the CESG (IC50: 2.3 ± 1.27 µg/mL) exhibited the highest activity. The BESG was the best scavenger of DPPH• (IC50: 2.91 ± 0.14 µg/mL). In the ABTS test, AERMA was the most active (IC50: 4.21 ± 0.28 µg/mL). However, with the CUPRAC, the BESG exhibited the best activity (A0.50: 0.15 ± 0.05 µg/mL) and was active in metal chelating assay with 48% inhibition at 100 µg/mL. The BESG was the best AChE inhibitor (IC50: 5.78 ± 0.01 µg/mL) however, the AERMA showed the highest BChE inhibitory activity (IC50: 19.23 ± 1.42 µg/mL). The tested extracts exhibited a good antibacterial activity. CONCLUSION: This study demonstrated good antioxidant, anticholinesterase and antibacterial potential of S. guyoniana and M. aquatica, which fits in well with their use in folk medicine.

Compounds from the pods of Astragalus armatus with antioxidant, anticholinesterase, antibacterial and phagocytic activities.

CONTEXT: The phytochemical study and biological activities of Astragalus armatus Willd. subsp. numidicus (Fabaceae) pods, an endemic shrub of Maghreb, are reported. OBJECTIVE: This study isolates the secondary metabolites and determines the bioactivities of Astragalus armatus pods. MATERIALS AND METHODS: The chloroform, ethyl acetate and n-butanol extracts of hydro-ethanolic extracts were studied. Antioxidant activity was investigated using DPPH and ABTS radical scavenging, CUPRAC and ferrous chelating assays at concentrations ranging from 3 to 200 µg/mL. Anticholinesterase activity was determined against acetylcholinesterase and butyrylcholinesterase enzymes at 50, 100 and 200 µg/mL. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) method. Carbon clearance method in albino mice was used for the phagocytic activity at concentrations 50, 70 and 100 mg/kg body weight. Spectroscopic techniques were used to elucidate the compounds. RESULTS: Ethyl acetate extract afforded a flavonoid (1) while the n-butanol extract gave four flavonoids (2-5), a cyclitol (6) and a cycloartane-type saponin (7). The ethyl acetate extract exhibited highest antioxidant activity in DPPH (IC50: 67.90 ± 0.57 µg/mL), ABTS (IC50: 11.30 ± 0.09 µg/mL) and CUPRAC (A0.50: 50.60 ± 0.9 µg/mL) assays. The chloroform extract exhibited the best antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, each with 80 µg/mL MIC values. The n-butanol extract enhanced phagocytic activity. DISCUSSION AND CONCLUSION: Isorhamnetin (1), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-ß-d-galactopyranoside (2), isorhamnetin-3-O-ß-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-ß-d-galactopyranoside (3), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-ß-d-galactopyranoside (4), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-ß-d-glucopyranoside (5), pinitol (6) and cyclomacroside D (7) were isolated whereas 1, 2, 6 and 7 are reported for the first time from A. armatus.