New lignan glycosides from Justicia secunda Vahl (Acanthaceae) with antimicrobial and antiparasitic properties.

Three new lignan glucosides, namely, justisecundosides A (1), B (2a), and C (2b), were isolated from the whole plant of Justicia secunda together with seven known compounds (3-9). Their structures were established based on a comprehensive analysis of HR-ESI-MS, IR, UV, and CD, in conjunction with their 1D and 2D-NMR data. A putative biogenetic pathway of compounds 1-2a,b from coniferyl alcohol was proposed. In addition, the antimicrobialactivities of the extract, fractions, and some isolated compounds were assessed against multiresistant bacterial and fungal strains. Furthermore, the antiplasmodial, antileishmanial, and antitrypanosomal activities were assessed against the sensitive (3D7) and multidrug-resistant (Dd2) strains of P. falciparum, promastigote and bloodstream forms of L. donovani, and Trypanosoma brucei, respectively. Compound 4 exhibited moderate antibacterial activity against Staphylococcus aureus SA RN 46003 with a MIC value of 62.5 µg/mL. Besides, compound 6 demonstrated a very good activity against sensitive (IC50Pf3D7: 0.81 µg/mL) and multidrug-resistant (IC50PfDd2: 14.61 µg/mL) strains of P. falciparum while compound 4 displayed good antitrypanosomal activity (IC50: 1.19 µg/mL). Also, compound 1 was the most active on the promastigote form of L. donovani with an IC50 of 13.02 µg/mL.

Foetidumins A-D, and other chemical constituents from Helichrysum foetidum (L.) Moench (Asteraceae) with antiparasite activity.

The phytochemical investigation of the MeOH and CH2Cl2-MeOH (1:1) extracts from the flowers and twigs of Helichrysumfoetidum (L.) Moench (Asteraceae), which showed antileishmanial and antiplasmodial activities during the preliminary screening, led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A (1) and B (2), one flavonoid, foetidumin C (3) and one chalcopyrone, foetidumin D (4). Additionally, fourteen known compounds comprising, two ent-beyer-15-ene-type diterpenoids (5-6), six flavonoids (7-12), two steroids (13-14), three triterpenoids (15-17), and one glyceryl monostearate (18) were also isolated. The chemical structures of foetidumins A-D were fully elucidated by analyses of their spectroscopic data. The structure and the stereochemistry of foetidumin A (1) were confirmed by SC-XRD analyses. Among the tested compounds, foetidumin C (3), erythroxylol A (6), and kaempferol (7) displayed the highest antileishmanial potency with IC50 values of 13.0, 11.8, and 11.1 µM, respectively. Foetidumin C (3) had no cytotoxicity toward Vero cells with the selectivity index > 3.59. Meanwhile, extracts of flowers and twigs had higher activity against Plasmodium falciparum chloroquine-sensitive (Pf3D7) strain with IC50 values of 3.66 and 10.52 µg/mL, respectively.

Constituents of the Stem Bark of Symphonia globulifera Linn. f. with Antileishmanial and Antibacterial Activities.

The chemical investigation of the n-hexane fraction from the methanol extract of the stem bark of Symphonia globulifera Linn f., which displayed good in vitro activity against Leishmania donovani NR-48822 promastigotes (IC50 43.11 µg/mL), led to the isolation of three previously unreported polyprenylated benzophenones, guttiferone U (1), V (2)/W (3), and a new tocotrienol derivative named globuliferanol (4), along with 11 known compounds (5-15). Their structures were elucidated based on their NMR and MS data. Some isolated compounds were assessed for both their antileishmanial and cytotoxic activities against L. donovani and Vero cells, respectively. Guttiferone K (5) exhibited the best potency (IC50 3.30 µg/mL), but with low selectivity to Vero cells. The n-hexane fraction and some compounds were also assessed in vitro for their antibacterial activity against seven bacterial strains. All the samples exhibited moderate to potent antibacterial activity (MICs ≤ 15.6 µg/mL) against at least one of the tested strains.

Desmoarylcoumarin and episoyasapogenol B: two new compounds from Desmodium salicifolium (Poir.) DC (Fabaceae).

A new 3-arylcoumarin, 7-hydroxy-6-(1,1-dimethylallyl)-2',5'-dihydroxy-4'-(3,3dimethylprenyl)-3-arylcoumarin (desmoarylcoumarin) 1, a previously unreported oleanane-type triterpenoid, 3ß,22ß,23-trihydroxyolean-12-en (episoyasapogenol B) 2, together with five known flavonoids including darbergioidin (3), isoferreirin (4), quercetin (5), vitexin (6), swertizin (7), and one carbohydrate, sucrose (8) were isolated from the methanolic extract of the roots of Desmodium salicifolium. Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D) and mass spectrometric (HRFAB-MS) data. The methanolic extract, EtOAc and n-BuOH fractions as well as some isolated compounds were assessed for their antibacterial and antioxidant activities. The EtOAc fraction exhibited moderate activity against Enterococcus faecalis with MIC value of 128 µg/mL. The methanolic extract and the EtOAc fraction displayed DPPH scavenging activity with EC50 values of 5.99 and 2.06 µg/mL, respectively. Compound 1 showed a moderate antibacterial activity against Enterococcus faecalis with a MIC of 16 µg/mL. It also showed moderate DPPH scavenging activity.

Antibacterial constituents of Rumex nepalensis spreng and its emodin derivatives.

The CH2Cl2-MeOH (1:1) extract of roots of Rumex nepalensis (Polygonaceae) displayed significant antibacterial activity against five bacterial strains with MICs (62.5-31.2 µg.mL-1). The EtOAc soluble fraction displayed a significant activity against the same strains with MICs (31.2-3.9 µg.mL-1). The purification of the EtOAc fraction yielded one new phenylisobenzofuranone derivative, berquaertiide (1), along with 19 known compounds (2-20). Their structures were elucidated based on the analysis of their NMR and MS data. All the isolated compounds were assessed for their antibacterial activity. Compound 2 was the most active against all the tested strains (15.7 to 1.9 µg.mL-1), while compounds 3-7 displayed good activities on at least one of the tested strains. In addition, seven analogues (21-27) of compound 2 were prepared and further assessed for their antibacterial activity. Compounds 26 and 27 were most active than 2 against Salmonella enterica and Klebsiella pneumoniae with MIC (125 and 15.6 µg.mL-1, respectively).

Echinocystic Acid Bidesmoside Saponins from Microglossa afzelii O. Hoffm and Their Cytotoxic Activity against the CAL-27 Oral Squamous Carcinoma Cell Line.

This paper describes eight new triterpenoid saponins, including afzeliioside A (1), four acetylated afzeliiosides as pairs of inseparable regioisomers, called afzeliiosides B/C (2/3) and D/E (4/5), afzeliiosides F-H (6-8), and a known impatiprin C (9), which were isolated from the n-BuOH fraction of the liana of Microglossa afzelii. Their structures were established mainly by extensive spectroscopic analysis, including 1D and 2D NMR, HRFAB-MS, tandem ESI-MS/MS, and chemical methods, as well as a comparison of their spectral data with those of related compounds. All the isolates were screened for their cytotoxic activity against the CAL-27 oral squamous carcinoma cell line. Only compounds 4/5 (EC50 = 36.0 µg/mL (32.7 µM)) exhibited moderate cytotoxic activity. This work presents the first chemical and biological investigation of Microglossa afzelii and reports, for the first time, on the isolation of saponins in the genus Microglossa.

Antimicrobial and Cytotoxic Activities of Constituents from the Fruit of Albizia lebbeck L. Benth (Fabaceae).

Twenty-two compounds were isolated from the fruit of Albizia lebbeck including one unprecedented, rare amino acid-derived zwitterionic and one new flavone derivative. The isolation was performed on repeated column chromatography over silica gel and their structures were determined by 1D-, 2D-NMR and HR-ESI-MS spectra together with reported data in the literature. The chemophenetic significance is also discussed. Some isolated compounds were reported for the first time to be found in the species. Additionally, compound 2 showed antibacterial activity and compounds 1 and 2 revealed moderate cytotoxic activity against the Raw 264.7 cancer cell line with IC50 values of 37.19 µM and 29.36 µM, respectively. Furthermore, a proposed biosynthetic pathway of compound 1 is described.

In Vitro Antilipidic and Antithrombotic Activities of Plectranthus glandulosus (Lamiaceae) Leaves Extracts and Fractions.

OBJECTIVE: The present study investigated the effect of the leaves extracts and fractions of Plectranthus glandulosus on the inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activity which may be important in atherosclerosis development. METHODS: Aqueous, ethanolic, and hydroethanolic extracts of Plactranthus glandulosus were prepared by maceration. The hydroethanolic extract was fractionated into n-hexane, ethylacetate, and n-butanol fractions and their inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activities measured. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis was carried out to determine phytochemical constituents present in the extracts. RESULTS: The standard orlistat exhibited a higher inhibitory activity on pancreatic lipase and cholesterol esterase (16.31 µg/mL and 15.75 µg/mL, respectively) compared to ethyl acetate fraction (IC50, 17.70 µg/mL and IC50, 24.8 µg/mL, respectively). Among crude extract, hydroethanolic extract showed a better inhibition against pancreatic lipase (IC50, 21.06 µg/mL) and cholesterol esterase (IC50, 25.14 µg/mL) though not comparable to the effect of orlistat. The best lipid uptake inhibition was observed in the hydroethanolic extract (IC50, 45.42 µg/mL) followed by the ethyl acetate fraction (IC50, 47.77 µg/mL). A better antithrombolytic activity was exhibited by the ethyl acetate fraction at all concentrations (50-800 µ/mL), while hydroethanolic extract exhibited the best activity among crude extract. However, these were not comparable to the standard aspirin. The LC-HRMS analysis revealed the presence of 7-O-methyl luteolin 5-O-ß-D-glucopyranoside, chrysoeriol 5-O-ß-D-glucopyranoside, 5,7-dihydroxy-3,2',4'-trimethoxyflavone, and plectranmicin as major compounds in both hydroethanolic extract and ethyl acetate fraction. CONCLUSION: Thus, our finding supports the traditional use of this plant, which might provide a potential source for future antiatherosclerotic drug discovery.