Volume 71, Issue 11-12

The triterpenes friedelin ( 1 ), β-friedelinol ( 2 ) and 3,15-dioxo-21α-hydroxyfriedelane ( 3 ) in the aerial parts of Maytenus robusta , a Brazilian medicinal plant with antiulcer potential, were seasonally quantified by gas chromatography flame-ionization detection (GC-FID) using an external standard. The method was found to be linear, precise and sensitive. Compounds 1 and 2 were found in M. robusta leaves and branches, with highest concentrations in the leaves collected in autumn, i.e. 3.21 ± 0.16 and 12.60 ± 1.49 mg g −1 dry weight of 1 and 2 , respectively. On the other hand, compound 3 was found only in the branches, with the highest concentrations in winter and autumn (0.21 ± 0.01 and 0.20 ± 0.02 mg g −1 ). The results allow to define the optimal season and plant parts for the collection of M. robusta as a phytotherapeutic drug.

Phytochemical investigation of the semi-parasitic plant, Plicosepalus curviflorus (Loranthaceae) growing in Saudi Arabia resulted in the isolation of a new catechin–gallic acid derivative of inositol, plicosepalin A ( 1 ) [(+) catechin-4′- O -(1″- O -galloyl-5″- O -methyl)- myo -inositol], along with seven known compounds: methyl gallate ( 2 ), catechin ( 3 ), quercetin ( 4 ), gallic acid ( 5 ), lupeol ( 6 ), β-sitosterol ( 7 ), and ursolic acid ( 8 ). Their structures were elucidated on the basis of spectroscopic analyses, including HRESIMS, ESIMS, 1 H and 13 C NMR, HSQC, and HMBC, as well as comparison with reported data. The antioxidant and antimicrobial activities of 1 were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the disc diffusion assay, respectively. Compound 1 exhibited potent free radical scavenging activity with an IC 50 value of 9.0 ± 0.27 μM. Moreover, significant activities against Staphylococcus aureus and Bacillus subtilis were recorded.

Three new lupan-type triterpernoid derivatives, namely globimetulin A ( 1 ), B ( 2 ) and C ( 3 ), were isolated from the shoot of Globimetula dinklagei (Loranthaceae), a hemiparasitic plant growing on Manihot esculenta , along with five known compounds: friedelin ( 4 ), friedelan-3-ol ( 5 ), 28-hydroxyfriedelin ( 6 ), 4-hydroxy-3,5-dimethoxybenzoic acid ( 7 ) and (1 R ,5 S ,7 S )-7-[2-(4-hydroxyphenyl)ethyl]-2,6-dioxabicyclo[3.3.1]nonan-3-one ( 8 ). The structures of the new compounds were elucidated by detailed analyses of their MS, IR, 1D and 2D NMR spectral data and chemical evidence. Some of these compounds were evaluated in vitro for their antimicrobial activities against a wide range of microorganisms, but none of them exhibited noticeable activity.

Two new antimicrobial fatty acid esters, penicilloitins A and B ( 1 and 2 ), along with α -cyclopiazonic acid ( 3 ), tryptamine ( 4 ) and indole-3-carbaldehyde ( 5 ), were isolated from mycelial extracts and the culture broth of a marine endophytic Penicillium species and their structures established by spectroscopic techniques including 1D ( 1 H NMR and 13 C NMR) and 2D NMR (COSY, multiplicity-edited HSQC, and HMBC) as well as HRESIMS. Of these compounds, 1, 3 and 4 displayed modest antimicrobial activity.

Ocimum is a genus of considerable importance in traditional medicine worldwide. The goal of this study was to examine the anti-acetylcholinesterase activity of Ocimum essential oils and to correlate the activity with their chemical profiles using a metabolome based GC-MS approach coupled to chemometrics. Further, molecular docking was adopted to rationalize the activity of some essential oil isolates. Essential oil prepared from the four species O. basilicum , O. africanum , O. americanum, and O. minimum exhibited significant anti-acetylcholinesterase activity with (IC 50 0.22, 0.175, 0.57 and 0.152 mg/mL, respectively) comparable to that of physostigmine (IC 50 0.27 mg/mL). The phenylpropanoids (i.e. estragole) constituted the most dominant chemical group in O. basilicum (sweet basil) and O. minimum , whereas camphor (a ketone) was the most abundant in O. africanum and O. americanum. Supervised and unsupervised multivariate data analyses clearly separated O. africanum and O. americanum from other accessions, with estragole, camphor and, to less extent, β-linalool contributing to species segregation. Estragole was found the most active AchE inhibitor (IC 50 0.337 µM) followed by cineole (IC 50 2.27 µM), camphor (IC 50 21.43 µM) and eugenol (IC 50 40.32 µM). Molecular docking revealed that these compounds bind to key amino acids in the catalytic domain of AchE, similar to standard drugs.

The purpose of our study was to compare the chemical compositions and antimicrobial and antioxidant activities of Pycnocycla spinosa and Pycnocycla flabellifolia essential oils. cis-Asarone (62.5%) and widdra-2,4(14)-diene (9%) were the main components of P. spinosa aerial part essential oil, while elemicin (60.1%) and caryophyllene oxide (9.8%) were the main components of P. spinosa seed essential oil. α-Phellandrene (25.5%), p-cymene (15.3%), and limonene (13.3%) were found in P. flabellifolia essential oil. The inhibition zone diameters for P. flabellifolia essential oil were significantly higher than for the two other essential oils from P. spinosa (p<0.05). In broth dilution assay (µL/mL), the sensitive microorganism to Pycnocycla sp. ( P. spinosa , P. flabellifolia ) was Aspergillus niger , followed by Candida albicans . In 2,2-diphenyl-1-picrylhydrazyl (DPPH) system, P. spinosa aerial parts essential oil (IC 50 =548 µg/mL) had higher antioxidant activity than that of two other essential oils.

A series of 2,5-disubstituted-benzoxazole derivatives ( 1–13 ) were evaluated as possible inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The results demonstrated that the compounds exhibited a broad spectrum of AChE and BChE inhibitory activity ranging between 6.80% and 90.21% except one compound which showed no activity against AChE at the specified molar concentration. Another derivative displayed a similar activity to that of reference drug (galanthamine) for inhibition of AChE and BChE. In addition, molecular docking of the compounds into active site of AChE was performed using recombinant human AChE (PDB ID: 4ey6) in order to understand ligand–protein interactions.

In this study, a comparative liquid chromatography/mass spectroscopy (LC/ESI-MS/MS) profiling of different fractions of Ulmus parvifolia leaves and stems was performed. Identification of compounds was based on comparing the mass spectrometric information obtained including m/z values and individual compound fragmentation pattern to tandem mass spectral library search and literature data. Eleven compounds were tentatively identified in the different analyzed fractions. One of the major constituents of this plant was isolated and identified as Icariside E4 [dihydro-dehydro-diconiferyl alcohol-4-O-α-L-rhamnopyranoside] ( 5 ). The evaluation of anti-inflammatory activity of the total methanolic extract using nitric oxide inhibition on LPS-stimulated RAW 264.7 cells model strong anti-inflammatory activity with 17.5% inhibition of nitric oxide production versus 10% inhibition for dexamethasone. The cytotoxic activity of the methanolic extract and Icariside E4 was evaluated against four types of human cell lines using MTT assay. Icariside E4 showed cytotoxic effect against Hep-G2, MCF-7, and CACO-2 cell lines compared to a negligible activity for the total extract. The same extract showed a moderate antioxidant activity with SC50=362.5 μg/mL.

This work describes the antiproliferative potential of 14 cyclic imides (methylphtalimides, carboxylic acid phtalimides and itaconimides) against several human cancer cell lines. The antiproliferative effect was evaluated using the sulforhodamine B assay. Although some compounds from methylphtalimide and carboxylic acid phtalimide classes exhibited a selective antiproliferative activity, the itaconimides ( 11–14 ) exhibited the best results, especially compound 14 , which presented a TGI (concentration that produces total growth inhibition) value of 0.0043 μM against glioma (U251), being inactive against the non-tumor cell line (HaCat). Absorption, distribution, metabolism and excretion in silico evaluations suggest that these compounds are promising candidates.

In continuation of our chemical investigation on some medicinal plants of the genus Achillea , chromatographic investigation of the methylene chloride/methanol (1:1) extract of the air-dried aerial part of Achillea biebersteinii Afan. (family Asteraceae) afforded a new natural monoterpene ( 2 ), in addition to two known sesquiterpenes ( 3 and 4 ). Compound 1 was isolated as light needle crystals. Structures were established on the basis of MS and NMR spectroscopic ( 1 H, 13 C, 1 H- 1 H correlation spectroscopy, heteronuclear multiple-quantum coherence and heteronuclear multiple-bond correlation) data and in case of compound 1 were confirmed by X-ray analysis. All isolated compounds were examined for their anti-inflammatory activity to inhibit lipopolysaccharide-induced NO production in RAW264.7 macrophage cells. Compounds 3 and 4 produced a promising anti-inflammatory effect (76% and 80% inhibition, respectively). However, compounds 1 and 2 produced moderate inhibition of NO release recording a 41% and 36% inhibition of NO production, respectively.