Megastigmane and phenolic components from Laurus nobilis L. leaves and their inhibitory effects on nitric oxide production

New sesquiterpenoids with neuroprotective effects in vitro and in vivo from the Picrasma chinensis

Three undescribed sesquiterpenes, designed as pichinenoid A-C (1-3), along with nine known ones (4-12) were isolated from the stems and leaves of Picrasma chinensis. The new isolates including their absolute configurations were elucidated based on extensive spectroscopic methods, single crystal X-ray diffraction, and electronic circular dichroism (ECD) experiments, as well as comparison with literature data. Structurally, compounds 1 and 2 are descending sesquiterpenes, while pichinenoid C (3) is a rare sesquiterpene bearing a 2-methylenebut-3-enoic acid moiety at the C-6 side chain. All the isolated compounds were tested for their neuroprotective effects against the H2O2-induced damage on human neuroblastoma SH-SY5Y cells, and most of them showed moderate neuroprotective activity. Especially, compounds 1, 3-5, and 7 showed a potent neuroprotective effect at 25 or 50 μM. Moreover, the neuroprotective effects of compounds 1 and 4 were tested on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mouse model. Results of western blot and immunofluorescence indicated that compound 4 significantly counteract the toxicity of MPTP, and reversed the expression of tyrosine hydroxylase (TH) in substantia nigra (SN) and striatum (ST) of the mouse brain. Interestingly, western blot data suggested compound 4 also enhanced B-cell lymphoma-2 (Bcl-2) and heme oxygenase 1 (HO-1) expressions in the brain tissues from MPTP damaged mouse.

Iridoids and other constituents from the leaves and stems of Valeriana officinalis var. latifolia

Fifty-nine compounds, including nineteen previously undescribed iridoids (valeriananols A-S) and an undescribed alkaloid (5'-isovaleryl uridine), were isolated from the leaves and stems of Valeriana officinalis var. latifolia. Their structures were elucidated based on Mass spectrometry and NMR spectroscopy. The absolute configuration of valeriananols A-C, E-N, P, Q and S was determined by experimental and calculated electronic circular dichroism. Structurally, valeriananols A and B were two 1,3-seco-iridoids with a 3,6-epoxy moiety, valeriananols K and L were a pair of C-4 epimers, while valeriananol S was a 4'-deoxy iridoid glycoside. In addition, valeriananol P, stenopterin A and patriscabioin C exhibited significant inhibition on nitric oxide production with IC50 values of 10.31, 3.93 and 8.69 μM, respectively. Furthermore, stenopterin A and patriscabioin C showed anti-proliferation activity on the MCF-7 cell line with IC50 values of 17.28 and 13.89 μM, respectively.

A new megastigmane glycoside, a new organic acid glycoside and other constituents with anticomplementary activity from Artemisia halodendron

A new megastigmane glycoside, (1R,5R,6S,7E)-megastigman-3,9-dione-7-en-6,11-diol 11-O-β-D-glucopyranoside (1), and a new organic acid glycoside, methyl (4 R)-4-O-β-D-glucopyranosyl-decanoate (2), together with eight known compounds (3-10), were isolated from the aerial parts of Artemisia halodendron Turcz. ex Bess. (Asteraceae). Their chemical structures were elucidated by 1 D and 2 D NMR and HR-ESI-MS spectra and DP4+ probability analysis. Among the identified compounds, compounds 5, 6 and 10 were isolated from the family Asteraceae, and compounds 3, 4 and 7-9 were identified from the genus Artemisia for the first time. All of the compounds were evaluated for their anticomplementary activity against the classical pathway (CP) and the alternative pathway (AP). Compounds 7 and 9 showed anticomplementary activity with the CH50 values of 0.31 ± 0.08 and 0.50 ± 0.09 mM, respectively.

Norsesquiterpenes from the Latex of Euphorbia dentata and Their Chemical Defense Mechanisms against Helicoverpa armigera

Euphorbia dentata (Euphorbiaceae), an invasive weed, is rarely eaten by herbivorous insects and could secrete a large amount of white latex, causing a serious threat to local natural vegetation, agricultural production and human health. In order to prevent this plant from causing more negative effects on humans, it is necessary to understand and utilize the chemical relationships between the latex of E. dentata and herbivorous insects. In this study, three new norsesquiterpenes (1-3), together with seven known analogues (4-10), were isolated and identified from the latex of E. dentata. All norsesquiterpenes (1-10) showed antifeedant and growth-inhibitory effects on H. armigera with varying levels, especially compounds 1 and 2. In addition, the action mechanisms of active compounds (1-3) were revealed by detoxifying enzyme (AchE, CarE, GST and MFO) activities and corresponding molecular docking analyses. Our findings provide a new idea for the development and utilization of the latex of E. dentata, as well as a potential application of norsesquiterpenes in botanical insecticides.

Tecomastane, a new megastigmane from the flowers of Tecoma stans

Tecoma stans is a tropical plant that is widely used in folk medicine. Little is known about the chemical constituents of flowers of this plant. From flowers of the native plant in Vietnam, 12 compounds were isolated and elucidated, including one new compound tecomastane (1) and eleven known compounds, (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmane-9-one (2), bosciallin (3), chakyunglupulin B (4), (2S,6R)-2,6-dimethyloctane-1,8-diol (5), cleroindicin F (6), rengyoxide (7), 3,4-dihydroxybenzoic acid (8), methyl 3,4-dihydrobenzoate (9), 3,5-dihydroxybenzoic acid (10), luteolin (11), and indole-3-carboxylic acid (12). Compound 5 was a new natural product. The chemical structures of isolated compounds were identified by interpretation of their spectroscopic data (1D, 2D NMR, and HRESIMS) and by comparison with the literature. Compounds 1-7 and 10-12 were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii.

Aromatic glycosides from the aerial part of Bupleurum chinense

A new aromatic glycoside (1) and twelve (2-13) known aromatic glycosides were isolated from the n-butyl alcohol of the 70% EtOH extract of the aerial part of Bupleurum chinense. Among them, compounds 4-7, 9, 11-13 were isolated from Umbelliferae plants for the first time. Their structures were elucidated by NMR and MS spectroscopy, and the absolute configuration of compound 1 was elucidated by single-crystal X-ray diffraction. Compounds 6 and 10 showed moderate cytotoxic activities on MGC-803 cell lines with IC₅₀ values of 8.63 ± 0.08 and 13.65 ± 1.73 μM, respectively.

Isolation of Laurus nobilis Leaf Polyphenols: A Review on Current Techniques and Future Perspectives

In recent years, the market demand for products enhanced with ingredients derived from natural products, such as polyphenols, is rapidly increasing. Laurus nobilis L., known as bay, sweet bay, bay laurel, Roman laurel or daphne is an evergreen Mediterranean shrub whose leaves have traditionally been used in cuisines and folk medicine due to their beneficial health effects, which can nowadays be scientifically explained by various biological activities of the leaf extracts. Many of these activities can be attributed to phenolic compounds present in L. nobilis leaves which include flavonoids, phenolic acids, tannins (proanthocyanidins) and lignans. In order to enable efficient industrial utilization of these valuable compounds, it is crucial to establish optimal extraction procedures resulting in the highest yields and quality of the extracts. This paper offers the first systematic review of current literature on the influence of conventional and advanced extraction techniques, including microwave-assisted, ultrasound-assisted, enzyme-assisted, supercritical-CO₂ and mechanochemical-assisted extraction on the phenolic content of L. nobilis leaf extracts, allowing more efficient planning of further research and simplifying the steps towards industrial utilization of this plant.

Chemical Constituents from the Leaves of Pachyrhizus erosus Collected in Vietnam

A phytochemical investigation of methanol extract from leaves of Pachyrhizus erosus (L.) Urban, a leguminous shrub distributed in Vietnam and other tropical and subtropical countries led to the isolation of a new prenylated chalcone, erosusone (1) and a new megastigmane glycoside epimer, 3-episedumoside F₁ (9), together with thirteen known compounds including flavonoids (2-6), a 3-benzoxepine lactone (7), a pyridine-4,5-diol derivative (8), megastigmanes and megastigmane glycosides (10-15). Their structures were elucidated by means of high resolution-electrospray ionization (HR-ESI)-MS, one dimensional (1D) and two-dimensional NMR (2D-NMR) spectroscopy as well as comparison with the data reported in the literature. The cytotoxic effects on LU-1 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MCF7 (breast carcinoma) cell lines were assessed. Prenylated chalcones 1-2 and isoflavone 3 exhibited cytotoxicity against all tested cell lines with IC₅₀ values ranging from 22.04 to 45.03 µM.

Three Active Phytotoxic Compounds from the Leaves of Albizia richardiana (Voigt.) King and Prain for the Development of Bioherbicides to Control Weeds

The global population is increasing day by day. To meet the food demand for such a huge number of people, crop production must increase without damaging the environment, and to prevent synthetic chemical herbicides from polluting the environment, controlling weeds using bioherbicides is essential. Accordingly, using phytotoxic substances obtained from plants for biological weed management has attracted attention. The plant Albizia richardiana possesses phytotoxic compounds that have been previously recorded. Hence, we have conducted this research to characterize more phytotoxic compounds in Albizia richardiana. Aqueous methanolic extracts of Albizia richardiana plant significantly restricted the growth of the examined plants lettuce and Italian ryegrass in a species- and concentration-dependent manner. Three active phytotoxic compounds were isolated through various chromatographic methods and identified as compound 1, 2, and 3. Compound 3 exhibited stronger phytotoxic potentials than the other two compounds and significantly suppressed the growth of Lepidium sativum (cress). The concentration of the compounds required for 50% growth reduction (I₅₀ value) of the Lepidium sativum seedlings ranged between 0.0827 to 0.4133 mg/mL. The results suggest that these three phytotoxic compounds might contribute to the allelopathic potential of Albizia richardiana.

Cassia fistula Leaves; UHPLC-QTOF-MS/MS Based Metabolite Profiling and Molecular Docking Insights to Explore Bioactives Role Towards Inhibition of Pancreatic Lipase

The present work was aimed at investigating hydroethanolic leaf extracts of Cassia fistula for their antioxidant and pancreatic lipase (PL) enzyme inhibitory properties. The most active extract was selected to profile the phytoconstituents by UHPLC-QTOF-MS/MS technique. Among the tested extracts, the 80% hydroethanolic extract exhibited the maximum levels of total phenolic and flavonoid contents (TPC and TFC) with a contribution of 201.3 ± 2.6 mg of gallic acid equivalent per gram of extract (GAE/g extract), and 116.3 ± 2.4 mg of rutin equivalent per gram of extract (RE/g extract), respectively. The same extract also showed promising 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and PL inhibitory activity with an IC₅₀ (half maximal inhibitory concentration) of 30.5 ± 2.8 µg/mL and 17.31 ± 1.18 μg/mL, respectively. The phytochemical profiling of 80% hydroethanolic extract confirmed the presence of 23 metabolites of immense medicinal significance. Docking studies were conducted to investigate the potential interactions of compounds identified in the study. The docking study-based binding energy data and the interaction scheme both revealed the possible role of the identified compounds towards PL inhibitor. Moreover, energies of frontier molecular orbitals (FMOs), ionization potentials (IP), electron affinities (EA) and molecular electrostatic potentials (MEP) were also explored. The findings of the current work suggest that C. fistula is a promising natural source of antioxidant and antiobesity agents, which may be exploited to add pharmacological functionalities to food.

Total synthesis of three natural phenethyl glycosides

Phenethyl glycosides having phenolic or methoxy functions at benzene rings are substances widely occurring in nature. This kind of compounds has been shown to have anti-oxidant, anti-inflammatory, and anticancer activities. However, some of them are not naturally abundant, thus the synthesis of such molecules is desirable. In this paper, natural phenethyl glycosides 3 and 4 were first totally synthesized from easily available materials with overall yields of 50.5% and 40.1%, respectively. And a new synthetic route to obtain natural phenethyl glycoside 2 in 46.2% yield was also described.

Lower COVID-19 mortality in Italian forested areas suggests immunoprotection by Mediterranean plants

The COVID-19 pandemic has induced dramatic effects on the population of the industrialized north of Italy, whereas it has not heavily affected inhabitants of the southern regions. This might be explained in part by human exposure to high levels of fine particulate matter (PM) in the air of northern Italy, thus exacerbating the mortality. Since trees mitigate air pollution by intercepting PM onto plant surfaces and bolster the human immune system by emitting bioactive volatile organic compounds (VOCs), we hypothesize a protective role of evergreen forested areas in southern Italy. We compared the mortality rate  due to COVID-19, the death number, the positivity rate and the forest coverage per capita in various Italian regions. Hectares of forest per capita and prevalence of deciduous versus evergreen forestal species were also estimated. In silico docking studies of potentially protective compounds found in Laurus nobilis L., a typical Mediterranean plant, were performed to search for potential antivirals. We found that the pandemic's severity was generally lower in southern regions, especially those with more than 0.3 hectares of forest per capita. The lowest mortality rates were found in southern Italy, mainly in regions like Molise (0.007%) and Basilicata (0.005%) where the forest per capita ratio is higher than 0.5 Ha/person. Our findings suggest that evergreen Mediterranean forests and shrubland plants could have protected the southern population by emission of immuno-modulating VOCs and provision of dietary sources of bioactive compounds. Moreover, in silico studies revealed a potential anti-COVID-19 activity in laurusides, which are unexplored glycosides from bay laurel. Overall, our results highlight the importance of nature conservation and applications to the search for natural antivirals.

Effect of some plant extracts from Egyptian herbal plants against Toxoplasma gondii tachyzoites in vitro

Nowadays, herbal extracts are considered to be a potential source for developing new drugs that will overcome resistance to conventional chemotherapeutic agents. This study was aimed to explore the efficacy of several Egyptian plant extracts against Toxoplasma gondii infection in vitro for future development of a new, safe, and effective compound for T. gondii. Methanol extracts from Matricaria chamomilla (German chamomile), Laurus nobilis, Citrullus colocynthis, Cinnamum camphora, Boswellia scara, and Melissa officionalis plants and oil extracts (either essential or fixed oils) of some plants such as: lemon grass (Cymbopogon citratus), marjoram (Origanum majorana), watercress (Nasturtium officionale), wheat germ (Triticum aestivum), sesame (Sesamum indicum), rosemary (Salvia rosmarinus), citronella (Cymbopogon nardus), clove (Syzygum aromaticum), jojoba (Simmondsia chinesis), and basil (Ocimum basilicum) were investigated for their anti-Toxoplasma activities. The methanol extracts from C. colocynthis and L. nobilis and the oil extracts from lemon grass and marjoram were active against T. gondii with half maximal inhibitory concentrations (IC₅₀) of 22.86 µg/ml, 31.35 µg/ml, 4.6 µg/ml, and 26.24 µg/ml, respectively. Their selectivity index (SI) values were <10. Interestingly, the methanol extract from M. chamomilla and oil from citronella had the lowest IC₅₀ values for T. gondii (3.56 µg/ml and 2.54 µg/ml, respectively) and the highest SI values (130.33 and 15.02, respectively). In conclusion, methanol extract from M. chamomilla and oil from citronella might be potential sources of novel therapies for treating toxoplasmosis.

Amine Derivative from the Aerial Part of Spilanthes acmella Murr. and their Alkaline Phosphatase Activity

Background:

Spilanthes acmella Murr. is included in Asteraceae family which is used as a traditional remedy for tooth-aches, and originated from Africa, America, Borneo, India, Sri Lanka, Bangladesh, China, Japan, Thailand, and Indonesia. The present research aims to isolate the amine derivative from the ethyl acetate layer of this plant and to evaluate the isolated compounds of alkaline phosphatase activity as a sign of bone formation.

Methods:

The air-dried plants of Spilanthes acmella Murr. were extracted with methanol, then partitioned with n-hexane and ethyl acetate successively by using liquid-liquid extraction, and then the chromatographic techniques were repeated, such as silica gel, octadecyl silylated silica gel, and HPLC. The isolated compounds were determined by spectrometric analysis using ultraviolet, infrared, high-resolution electrospray ionization mass spectrometry, 1D and 2D NMR.

Results:

Benzenepropanoic acid, 4 hydroxy-2-oxo-3 piperidinyl ester (1), was isolated from the ethyl acetate layer of the whole plants of Spilanthes acmella Murr. together with dendranthemoside A (2), uridine (3), icariside B2 (4), chicoriin (5), dendranthemoside B (6), and ampelopsisionoside (7) from their butanol layer.

Conclusion:

An amine derivative, a benzenepropanoic acid that determined as 4 hydroxy-2-oxo-3 piperidinyl ester (1) was isolated and reported for the first time from the ethyl acetate layer of Spilanthes acmella naturally. All the isolated compounds from this plant stimulated alkaline phosphatase activity as a mark of bone formation up to 128%.

New Methyl Threonolactones and Pyroglutamates of Spilanthes acmella (L.) L. and Their Bone Formation Activities

In our continuing research for bioactive constituents from natural resources, a new methyl threonolactone glucopyranoside (1), a new methyl threonolactone fructofuranoside (2), 2 new pyroglutamates (3 and 4), and 10 known compounds (5–14) were isolated from the whole plant of Spilanthes acmella (L.) L. The structures of these compounds were determined based on various spectroscopic and chemical analyses. All of the isolated compounds were evaluated on bone formation parameters, such as ALP (alkaline phosphatase) and mineralization stimulatory activities of MC3T3-E1 cell lines. The results showed that the new compound, 1,3-butanediol 3-pyroglutamate (4), 2-deoxy-d-ribono-1,4-lactone (6), methyl pyroglutamate (7), ampelopsisionoside (10), icariside B₁ (11), and benzyl α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside (12) stimulated both ALP and mineralization activities.

Undescribed phenylpropanoid and a dimeric sesquiterpenoid possessing a rare cyclobutane ring from Tinospora sinensis

A rare dimeric sesquiterpenoid (tinosposinoside, 1) and a phenylpropanoid (cordifolioside C, 2), two undescribed metabolites, were isolated from the methanolic extract of the stems of Tinospora sinensis together with thirteen known compounds. This is the second example of a sesquiterpene dimer where two monomers linked together through a cyclobutane ring, possibly generated through [2 + 2] cycloaddition. The structures of 1 and 2 were elucidated by NMR and mass techniques.

Megastigmane Derivatives from the Cladodes of Opuntia humifusa and Their Nitric Oxide Inhibitory Activities in Macrophages

Opuntia humifusa, known as the eastern prickly pear cactus and locally called "Cheonnyuncho" in Korea, is cultivated widely on Jeju Island, Korea. Phytochemical analysis of the methanolic extract of the cladodes of O. humifusa, for which previous research is relatively limited, was performed under the guidance of LC/MS-based analysis. As a result, one new megastigmane (1) and four new megastigmane glucosides (2-5) were isolated along with 18 known compounds (6-23). The structures of the new compounds were established by 1D and 2D NMR and HRESIMS, and their absolute configurations were established by chemical reactions, quantum chemical electronic circular dichroism calculations, and DP4+ analysis using the gauge-including atomic orbital NMR chemical shift calculations as well as the application of Snatzke's method. The isolated compounds (1-23) were tested for NO production inhibition in lipopolysaccharide (LPS)-induced RAW 264.7 cells to investigate their anti-inflammatory effects. Compounds 10 and 11 exhibited significant inhibitory effects on LPS-induced NO production in a dose-dependent manner. The potential mechanistic pathway of 10 and 11 was also investigated using Western blotting, indicating that compounds 10 and 11 inhibit NO through iNOS expression.

Constituents from the Leaves of Tetraena mongolica and Their Protective Activity in HEK 293t Cells Damaged by CdCl2

Tetraena mongolica Maxim, a relict originating from the Tertiary Period, is an endemic species of Zygophyllaceae in China. Three new monoterpenoids (1-3), two new phenols (4, 5) with unusual O-sulfoglucosyl groups, a new flavonoid (6), and nine known compounds were isolated from the leaves of T. mongolica. The structures of these compounds were determined by interpretation of NMR, MS, and ECD data. Some of the isolated compounds showed protective effects on HEK 293t cells damaged by CdCl₂, with IC₅₀ values being 55.7 and 80.3 μM for compounds 7 and 8, respectively, at the time point of 48 h after treatment.

Eudesmane-type sesquiterpene glycosides: sonneratiosides A-E and eudesmol β-D-glucopyranoside from the leaves of Sonneratia alba

Five eudesmane-type sesquiterpene glycosides, named sonneratiosides A-E (1-5), were isolated from the leaves of Sonneratia alba (Lythraceae). The aglycone of sonneratioside A was identified as cryptomeridiol also known as proximadiol. X-ray crystallographic analysis of sonneratioside A confirmed its structure and its absolute stereochemistry. Eudesmol β-D-glucopyranoside (6) was also isolated from nature for the first time. The tyrosinase inhibitory activity was assayed for the new compounds together with seven known compounds. Among them, arbutin (12) showed the expected activity and luteolin 7-O-rutinoside (10) showed comparable activity to arbutin.

A new C-glycosyl flavone and a new neolignan glycoside from Passiflora edulis Sims peel

A new C-glycosyl flavone, Chrysin-8-C-(2″-O-β-6-deoxy-glucopyranosyl)-β-D-glucopyranoside (1), a new neolignan glycoside, citrusin G (2), as well as 15 known compounds (3-17) were isolated from the peel of Passiflora edulis Sims. The structure determinations were primarily based on comprehensive spectroscopic analyses, and the absolute configuration of 2 were unequivocally determined by the CD experiment and chemical transformation. Compound 1 represents the rare examples of the flavonoid featuring a deoxy glucose sugar moiety. Compounds 5, 7 and 9 exhibited moderate inhibitory effects on nitric oxide (NO) production stimulated by lipopolysaccharide (LPS) in RAW 264.7 cells, with IC₅₀ values of 34.92, 16.12 and 26.67 μM, respectively.

Phytochemical study of Juglans regia L. leaves

A methanolic extract of Juglans regia L. leaves was fractioned by various chromatographic techniques yielding a total of 40 metabolites belonging to megastigmane, tetralone, phenylpropanoid, neolignane and juglone glycosides. Ten unknown megastigmane glucoside derivatives (juglanionosides A-K, 1-10) and six unknown tetralone glucoside derivatives (juglanosides J-O, 11-16) together with 24 known compounds - among them 16 described for the first time in Juglans - were isolated. As characteristic structural feature, the previously undescribed compounds showed acylation of the sugar units with sinapic, ferulic, coumaric, benzoic or salicylic acid. Their chemical structures were elucidated on the basis of 1D and 2D NMR techniques, HRESIMS as well as CD spectroscopy. Absolute stereochemistry was revealed by mild alkaline hydrolysis and comparison of CD and polarimetric data to literature values.

Phytochemicals and Biological Activities of Laurel Tree (Laurus nobilis)

This review summarizes the chemical composition reported up to date on Laurus nobilis L. (Lauraceae), an evergreen shrub or tree cultivated for its aromatic leaves and ornamental interest. It has been focused on non-volatile phytochemicals such as sesquiterpene lactones, flavonoids and proanthocyanidins, among others. Moreover, biological activities of laurel extracts and pure compounds have also been reviewed.

Bioactive composition of Reevesia formosana root and stem with cytotoxic activity potential

Three lignanoids and three terpenoids, along with 40 known compounds were isolated from Reevesia formosana.

New Alkaloids and Anti-inflammatory Constituents from the Leaves of Antidesma ghaesembilla

Using various chromatographic methods, two new alkaloids, antidesoic acids A (1) and B (2) along with fourteen known compounds (3-16) were isolated from the leaves of Antidesma ghaesembilla Gaertn. Their chemical structures were elucidated by physical and chemical methods. All the isolated compounds were evaluated for their inhibitory activity on LPS-stimulated nitric oxide (NO) production in BV2 cells and RAW 264.7 macrophages. Bisflavone 8 significantly inhibited LPS-stimulated NO production in BV2 cells and RAW 264.7 macrophages with IC50 values of 5.4 and 8.0 μM, respectively. Compounds 1–3, 7, 10, 12, 14, and 16 showed moderate inhibitory activities with IC50 values ranging from 11.7 to 77.4 μM.

Drug Affinity Responsive Target Stability (DARTS) Identifies Laurifolioside as a New Clathrin Heavy Chain Modulator

Five new diterpenes (1-5) and a megastigmane derivative (6) were isolated from the aerial parts of Euphorbia laurifolia, along with several known compounds. Their structures were elucidated by NMR, MS, and ECD and by chemical methods. A chemical proteomics drug affinity responsive target stability (DARTS) approach to investigate the lathyrane diterpene 1, laurifolioside, on its putative cellular target(s) was performed. Clathrin heavy chain 1, a protein mainly involved in selective uptake of proteins, viruses, and other macromolecules at the plasma membrane of cells, was identified as the major interaction partner of compound 1. The modulation of clathrin activity by 1 was studied through microscopy, molecular docking, and molecular dynamics studies, suggesting a new activity of lathyrane diterpenes in the modulation of trafficking pathways.

Dietary effect of dried bay leaves (Laurus nobilis) meal on some biochemical parameters and on plasma oxidative status in New Zealand white growing rabbit

Effects of dietary supplementation of Laurus nobilis on selected biochemical parameters and plasma oxidative status in growing rabbits, fed with and without enriched-fat diet, integrated with and without dried bay leaves meal, were investigated. In the test, 120 New Zealand white 35-day-old male rabbits were divided into four homogeneous groups of 30 animals each. A negative control group (CON) received a feed that met the animal nutrient requirement; a positive control group (CG) receiving a supplement of 2.5% pig fat in feed; an experimental group (GA) feeding an integration of 2.5% pig fat and 1 g/kg of dried bay leaves (Laurus nobilis) in feed; an experimental group (CA) with dried bay leaves at the rate of 1 g/kg in feed. The dietary integration with dried bay leaves meal have resulted in a significant decrease in the blood lipid profile, glycemic profile and liver enzymes, with reduced levels of ALT and AST, glucose, total cholesterol, LDL cholesterol, triglycerides and increased HDL cholesterol. Plasma oxidative status markers have statistically improved with an increase in blood total phenols, SOD, ORAC, the FRAP and lipo-vitamin concentration, together with a significant reduction in ROMs and the MDA values. The results of present research underline that the dietary treatment with bay leaves meal, in the extend of 1 g/kg feed, confirms the lowering cholesterol activity and the epato-protective and ipo-glycemic effect in enrich-fat diet, controlling the oxidative status of plasma markers.

Cytotoxicity of South-African medicinal plants towards sensitive and multidrug-resistant cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine plays a major role for primary health care worldwide. Cancer belongs to the leading disease burden in industrialized and developing countries. Successful cancer therapy is hampered by the development of resistance towards established anticancer drugs.

AIM

In the present study, we investigated the cytotoxicity of 29 extracts from 26 medicinal plants of South-Africa against leukemia cell lines, most of which are used traditionally to treat cancer and related symptoms.

MATERIAL AND METHODS

We have investigated the plant extracts for their cytotoxic activity towards drug-sensitive parental CCRF-CEM leukemia cells and their multidrug-resistant P-glycoprotein-overexpressing subline, CEM/ADR5000 by means of the resazurin assay. A panel of 60 NCI tumor cell lines have been investigated for correlations between selected phytochemicals from medicinal plants and the expression of resistance-conferring genes (ABC-transporters, oncogenes, tumor suppressor genes).

RESULTS

Seven extracts inhibited both cell lines (Acokanthera oppositifolia, Hypoestes aristata, Laurus nobilis, Leonotis leonurus, Plectranthus barbatus, Plectranthus ciliates, Salvia apiana). CEM/ADR5000 cells exhibited a low degree of cross-resistance (3.35-fold) towards the L. leonurus extract, while no cross-resistance was observed to other plant extracts, although CEM/ADR5000 cells were highly resistant to clinically established drugs. The log10IC50 values for two out of 14 selected phytochemicals from these plants (acovenoside A and ouabain) of 60 tumor cell lines were correlated to the expression of ABC-transporters (ABCB1, ABCB5, ABCC1, ABCG2), oncogenes (EGFR, RAS) and tumor suppressors (TP53). Sensitivity or resistance of the cell lines were not statistically associated with the expression of these genes, indicating that multidrug-resistant, refractory tumors expressing these genes may still respond to acovenoside A and ouabain.

CONCLUSION

The bioactivity of South African medicinal plants may represent a basis for the development of strategies to treat multidrug-resistant tumors either by phytotherapeutic approaches with whole plant preparations or by classical drug development with isolated compounds such as acovenoside A or ouabain.

Taraxerol 4-Methoxybenzoate, an in vitro Inhibitor of Photosynthesis Isolated from Pavonia multiflora A. St-Hil. (Malvaceae)

A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.

Chemical Constituents and Derivatization of Melodorinol from the Roots of Melodorum fruticosum

Chemical investigation of the CH2Cl2 and MeOH crude extracts of the roots of Melodorum fruticosum Lour. led to the isolation of 15 known compounds, of which 5, 10, and 12-15 are reported for the first time from this plant. In addition, melodorinol (7) was derivatized to afford six new (7a-7d and 7f-7g) analogues and one known compound (7e). Their structures were identified on the basic of spectroscopic data. Most of them were evaluated for their cytotoxicity against KB, HeLa, MCF-7 and HepG-2 cell lines. Compounds 4 and 7b were the most potent to all cell lines.

An iridoid glucoside and the related aglycones from Cornus florida

A new iridoid glucoside, cornusoside A (1), and four new natural product iridoid aglycones, cornolactones A-D (2-5), together with 10 known compounds were isolated from the leaves of Cornus florida. The structures of compounds 1-5 were established by interpretation of their spectroscopic data. Cornolactone B (3) is the first natural cis-fused tricyclic dilactone iridoid containing both a five- and a six-membered lactone ring. A biosynthesis pathway is proposed for cornolactones C (4) and D (5), the C-6 epimers of compounds 1-3.

Sesquiterpenes inhibiting the microglial activation from Laurus nobilis

The inhibitory reagents to inhibit the activation of microglial cells may be potentially useful for the treatment of neurodegenerative diseases. The leaves of the plant Laurus nobilis belonging to the family Lauraceae, namely, bay leaves, have been used as a popular spice, and their extract showed moderate inhibition on microglial activation. A further phytochemical investigation of the leaves led to the isolation of two new (1, 2) and eight known (3-10) sesquiterpenes. Their structures were elucidated on the basis of extensive 1D and 2D NMR (HMQC, HMBC, (1)H-(1)H COSY, and NOESY) spectroscopic data analyses and Chem3D modeling. The following biological studies disclosed that these isolated compounds showed inhibitory activities on LPS-induced microglial activation. The results of our phytochemical investigation, including two new sesquiterpenes (1 and 2) and the first report of two compounds (3 and 4) from this species, further revealed the chemical composition of bay leaves as a popular spice, and the biological studies implied that bay leaves, containing bioactive substances with the inhibition of microglial activation, were potentially beneficial to human health.

Flavonoids and stilbenoids from Derris eriocarpa

One new resveratrol analogue, 1-(3',4',5'-trimethoxyphenyl)-2-methoxy-2-(4″-methoxyphenyl)-ethane-1-ol (1), and two new prenylisoflavones, 4'-hydroxy-5,7-dimethoxy-6-(3-methyl-2-butenyl)-isoflavone (2), and derrubon 5-methyl ether (3), together with 17 known compounds including one new natural product, 5,7-dihydroxy-3-[4'-O-(3-methyl-2-butenyl)-phenyl]-isoflavone (4), were isolated from the stems of ethnomedicinal plant Derris eriocarpa How. (Leguminosae). Their structures were elucidated based on chemical evidence and spectroscopic techniques including two-dimensional NMR methods. All compounds are reported from this species for the first time. Antimicrobial activities of the new compounds were evaluated. Compound 2 exhibited good inhibitory activities against Candida guilliermondii, C. albicans and Microsporium gypseum with the minimal inhibitory concentration (MIC) values of 12.5 μg/ml.

Apolar Laurus nobilis leaf extracts induce cytotoxicity and apoptosis towards three nervous system cell lines

In the course of a bioactivity screening of Mediterranean plants, the assessment of neuroprotective properties of Laurus nobilis L. was of interest. Dried leaves were extracted by sonication using CHCl3 as solvent. The CHCl3 parental extract (CHCl3-pe) was fractionated to yield CHCl3 (LnC-1), EtOAc (LnC-2), MeOH (LnC-3) fractions. Each fraction underwent an extensive screening towards human neuroblastoma (SK-N-BE(2)-C, and SH-SY5Y) and rat glioma (C6) cell lines. MTT and SRB cytotoxicity tests were performed. The effect on the plasma membrane integrity was evaluated by assessment of LDH release. The caspase-3 activation enzyme and DNA fragmentation were also evaluated. The oxidant/antioxidant ability of all the extracts were evaluated using different methods. Furthermore, a metabolite profiling of the investigated extracts was carried out by GC-EI-MS. CHCl3-pe contained terpenes, allylphenols, and α-tocopherol. Dehydrocostus lactone was the main constituent. As result of the fractionation technique, the LnC-1 extract was mainly composed of α-tocopherol, whereas the LnC-2 fraction was enriched in guaiane and eudesmane terpenes. The most cytotoxic LnC-2 fraction induced apoptosis; it was ineffective in preventing in vitro free radicals production. Overall, the experimental results support a possible role of LnC-2 preparation as a chemopreventive agent for neuronal cells or other cells of the CNS.

Aluminium phosphide-induced genetic and oxidative damages in vitro: attenuation by Laurus nobilis L. leaf extract

Objective:

The present investigation was undertaken to assess the protective effect of Laurus nobilis leaf extract (LNE) against aluminum phosphide (AIP)-induced genotoxic and oxidative damages stress in cultured human blood cells in the presence of a metabolic activator (S9 mix).

Materials and Methods:

Sister chromatid exchange (SCE) and chromosome aberration (CA) assays were used to assess AlP-induced genotoxicity and to establish the protective effects of LNE. In addition, we determined total antioxidant capacity (TAC) and total oxidative status (TOS) levels in AlP and LNE treated cultures for biomonitoring the oxidative alterations.

Results:

There was significant increases (P < 0.05) in both SCE and CA frequencies of cultures treated with AlP as compared to controls. Our results also showed that AlP (58 mg/l) caused oxidative stress by altering TAC and TOS levels. However, co-application of LNE (25, 50, 100 and 200 mg/l) and AlP resulted in decreases of SCE, CA rates and TOS level and increases of TAC level as compared to the group treated with AlP alone.

Conclusion:

The preventive role of LNE in alleviating AlP-induced DNA and oxidative damages was indicated for the first time in the present study.