Air-dried Plant Material Research Articles

Phytochemistry, Anti-Tyrosinase, and Anti-Diabetes Studies of Extracts and Chemical Constituents of Dicerothamnus rhinocerotis Leaves

Dicerothamnus rhinocerotis (L.f.) Koekemoer, also known as rhinoceros bush and previously called Elytropappus rhinocerotis (L.f.) Less., is from the Asteraceae plant family. The plant is traditionally used to treat indigestion, stomach ulcers, influenza, and diarrhea. This study was aimed at investigating the phytochemistry, anti-glucosidase, anti-amylase, and anti-tyrosinase effects of D. rhinocerotis as research in this area is limited. The air-dried plant materials were macerated in 80% methanol (MeOH) and fractionated between hexane, dichloromethane (DCM), ethyl acetate (EtOAc), and butanol (BuOH). Column chromatography on silica gel was employed for the isolation of the compounds. A total of six compounds (1–6) were isolated from the fractions viz. acacetin (1), 15-hydroxy-cis-clerodan-3-ene-18-oic-acid (2), acacetin-7-glucoside (3), pinitol (4), apigenin (5), and β-sitosterol-3-O-glycoside (6). Compounds 2–4 and 6 are reported for the first time from this plant. Among the different fractions, the BuOH and EtOAc fractions had strong tyrosinase inhibitory activities with IC50 values of 13.7 ± 1.71 and 11.6 ± 2.68 µg/mL, respectively, while among the isolated compounds, apigenin (5) had the strongest inhibitory activity, with an IC50 of 14.58 µM, which competes favorably with Kojic acid (17.26 µM). The anti-glucosidase assay showed good activity in three of the fractions and compound 5, while the anti-amylase assays did not show significant inhibition activity.

Pharmacognostic Evaluation of Platycerium bifurcatum (Cav.) C. Chr. (Polypodiaceae)

Ethnopharmacological relevance: Platycerium bifurcatum (CAV.) C. Chr., Commonly known as staghorn fern is an epiphytic plant with diverse medicinal uses, such as anti-ulcer remedy, treating oedema, coughs and hypertension. This research was aim at evaluating the pharmacognostic profile of P. Bifurcatum. Methods: The fresh and air-dried plant materials were evaluated for microscopic characters, ash values, extractive values, moisture content and phytoconstituents. Results: Pharmacognostic evaluation revealed two shape of leaves, one round and the other forked-like shape, dark and light green colour, slightly coarse texture at the abaxial surface and hairy due to the trichome at the adaxial surface, reticulate leaf venation and margin entire, presence non- grandular stellate trichomes at the lower epidermal layer, spongy mesopghyll, collenchyma cells, vascular bundles straight type of epidermal cell wall, anisocytes stomata. Moisture content of 6.283%, total ash value of 8.25% within the standard range, acid insoluble ash of 1%, water soluble of 6.0% and phytochemical screening analysis shows the presence of phenolic, saponins, glycosides and triterpenoid constituents. Conclusion: this study reports the first time the pharmacognostic properties of P. bifurcatum.

Chemical Composition and Antioxidant Activity of Essential Oil from the Aerial Parts of Teucrium luteum (Mill.) Degen subsp. flavovirens (Batt.) Greuter & Burdet Growing Wild in Tunisia

Essential oils (EOs), the odorous and volatile products of a plant’s secondary metabolism, have wide applications in folk medicine, in food flavoring and preservation, and in fragrance industries. The aim of this study was to analyze the chemical composition of the EO from the aerial parts (including the inflorescences) of wild Teucrium luteum subsp. flavovirens from Tunisia. The EO obtained by the hydrodistillation of air-dried plant material in a Clevenger-type apparatus was analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Fifty-three components representing 83.9% of the total constituents were identified. The EO of T. luteum subsp. flavovirens is characterized by the presence of β-elemol (7.2%), (+)-α-pinene (6%), β-eudesmol (5.5%), guaiol (4.2%), α-bisabolol (4.2%), and β-caryophyllene (4.1%) as principal chemical components. In vitro (DPPH and β-carotene bleaching assays), it showed significantly higher radical scavenging and antioxidant properties than the reference compound, BHT. To the best of our knowledge, this is the first report describing the composition and antioxidant properties of the EO from Tunisian T. luteum subsp. flavovirens. Our preliminary data will help to valorize this potentially useful plant species from Tunisia and represent a starting point for further studies on its volatile fraction.

Study of Antimicrobial, Antioxidant and Cytotoxicity Properties of Selected Plant Extracts for Food Preservative Applications

An attempt has been made to evaluate antimicrobial, antioxidant and cytotoxicity properties of extracts from onion (Allium cepa L.), garlic (Allium sativum), leaves of guava (Psidium guajava), papaya (Carica papaya), tea (Camellia sinensis), baen (Avicennia alba) and keora (Sonneratia apetala), respectively to apply as natural preservatives for tomatoes. The air-dried plant materials of the respective plant species were subjected to ethanol-methanol extraction, concentrated and stored at 4 °C before use. The extracts were dissolved in 95% ethanol for analysis of antioxidant and antimicrobial properties. Of the extracts tested, tea extracts showed the highest zone of inhibition against several pathogenic bacteria (E. coli 35.0±3.2 mm; P. aeruginosa 29.3±2.6 mm; S. typhi 28.4±2.1 mm and S. pyogenes 27.7±3.7 mm) using the disc diffusion method. In regard to DPPH free radical scavenging assay, keora and guava extracts showed the highest percentage of radical scavenging activity with the values of 89.64± 0.18 and 89.39± 0.88, respectively, which were in agreement with higher total antioxidant capacity (TAC) of these extracts obtained by the phosphomolybdenum method. Brine shrimp lethality bioassay for cytotoxicity assessment showed LC50 of 132.54 ± 18.99 µg/mL for the leaf extract of keora which was found to be most toxic among all studied extracts. The initial results indicated that the extracts could be used for food preservative applications based on the antimicrobial, antioxidant and cytotoxicity properties of the tested extracts. However, efficacy, stability and safety issues need to be addressed with both in vitro and in vivo studies.

Preliminary phytochemical screening and antioxidant activity of five medicinal plants of garhwal himalaya: a comparitive study

The Garhwal Himalayan region is rich in medicinal plants, greatly valued by local inhabitants for health care needs. In this study five different medicinal plants i.e., Bunium persicum, Dactylorhiza hatagaria, Satyrium nepalense, Urtica diocia, and Viscum album of Garhwal Himalayan region were screened for the presence of major phytochemical compounds and also analyzed for their antioxidant activity. The air-dried plant materials were extracted with methanol using soxhlet extraction method. Phytochemical screenings of each plant parts (methanol extract) were resolute through standard biochemical analysis and their antioxidant activity were examined by DPPH assay. All the extracts showed the presence of carbohydrates except Urtica diocia. Satyrium nepalense and Dactylorhiza hatageria showed the presence of alkaloids, flavonoids, saponins, and steroids. Viscum album and Urtica diocia showed the presence of flavonoids and phenols. Bunium persicum did not show the presence of saponins and flavonoids. DPPH free radical scavenging activity indicated that the methanol extract of Satyrium nepalense possesses the higher antioxidant activity while the lower was found in Urtica diocia. IC50 value of methanol extracts of Bunium persicum, Dactylorhiza hatageria, Satyrium nepalense, Urtica diocia and Viscum album were 0.09, 0.21, 0.04, 0.42 and 0.14 mg/ml respectively. However,the result reveals that Satyrium nepalense contains potent phytochemicals and thus further studies can be done for its therapeutic uses.

Phytochemical Screening and HPTLC study of Padina tetrastromatica (Hauck)

The marine ecology is diverse with innumerable types of natural substances, both of plant and animal origin. Padina tetrastromatica (PT) (Hauck) is a brown algae belonging to the order Dictyotales, found in coastal region. The objective of present investigation was to evaluate phytochemical profile of extracts of PT. The air dried plant material was defatted and extracted successively with solvents of increasing polarity. Incumbent study was performed with standard qualitative phytochemical tests and HPTLC fingerprint analysis using CAMAG HPTLC system. The results showed the presence of phytoconstituents like sterols, terpenoids, flavonoids, glycosides, alkaloids and carbohydrates. Furthermore, components present in extracts were resolved in best possible solvent system by HPTLC. The chloroform extract of PT displayed eight peaks, in which those with Rf values 0.28 and 0.72 were more predominant. Whereas ethanol extract of PT exhibited nine peaks, in which maximum Rf value was found to be 0.82. In conclusion, the data of this study provide useful guide and suitability for investigation of biological activity of the plant according to the phytochemical groups observed. However, further work is needed to standardize the above chemical constituents in comparison with biomarker and this result can also be measured along with the other data for setting up the standards to this plant.

In Vitro Anti-Helicobacter Pylori and Antimycobacterial Activity Evaluation Of Selected Plants From Turkey

In this study, the extracts of Ulmus minor Mill. subsp. minor (Ulmaceae), Lathyrus pratensis L. (Leguminosae), Glaucium leiocarpum Bois. (Papaveraceae), and Echium vulgare L. (Boraginacea) were investigated for their in vitro anti-Helicobacter pylori and anti-mycobacterial activity. 
 The air-dried plant material was powdered and extracted with 70% ethanol by maceration. The extract was filtered and evaporated to dryness under the vacuum and then dissolved in a water-ethanol (90:10) mixture and extracted with dichloromethane and ethyl acetate, respectively. Antibacterial activity was investigated by microdilution method against Helicobacter pylori ATCC 43504, Mycobacterium smegmatis ATCC 14468 and Mycobacterium avium ATCC 25291.
 The ethyl acetate extract of U. minor showed activity with MIC of 250 µg / mL against H. pylori. The other extracts showed no or weak inhibitory activity at >2000 µg/mL concentrations against the tested microorganisms. In conclusion, ethyl acetate extract of U. minor may be used for the treatment of H. pylori infections.

Analysis of the essential oil composition of three cultivated Nepeta species from Iran

Essential oils (EOs) of three Iranian cultivated Nepeta species were investigated. The oils were obtained by hydrodistillation of air-dried plant materials at full flowering stage and analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectroscopy (GC/MS). In total, 89 compounds were detected. In over 2 years, a number of constituents were identified in the EO of Nepeta binaloudensis first and second years (26 and 37, respectively), Nepeta cataria (25 and 32, respectively), and Nepeta assurgens (45 and 50, respectively). In the oils of N. binaloudensis, 4a-α,7-α,7a-α-nepetalactone (NL) 59.7% and 1,8-cineole (19.6%) during the first and second years, respectively, were the main constituents. The main components of N. cataria were 4a-α,7-α,7a-β-NL (72.8%) and 4a-α,7-β,7a-α-NL (73.9%) during the first and second years, respectively, and 4a-α,7-α,7a-α-NL (55.5%) and 1,8-cineole (24.1%) during the first and second years, respectively, were the main constituents of N. assurgens. The results showed that NLs isomers and 1,8-cineole were the main components of the oils of three cultivated Nepeta species.

Chemical constituents from Saussurea pachyneura

Background: Genus Saussurea is famous for its use in traditional Chinese medicine. Objectives: Saussurea pachyneura, a plant from genus Saussurea, was studied for its secondary metabolites. Materials and Methods: The air-dried whole plant material was extracted by ethanol. The compounds from the ethanolic extract were isolated and purified by silica gel, octadecylsilyl-silica gel, and Sephadex LH-20 column chromatography. Their structures were identified based on the spectral analysis. Results: A total of 13 compounds, including a new long-chain fatty acid ester (4), were isolated and identified from the ethanolic extract of S. pachyneura. Conclusion: This is the first study to report the phytochemical analysis of S. pachyneura and also the first study to isolate the compounds from ethanolic extract of the whole plant material of S. pachyneura.

Antimicrobial and Alpha-Amylase Inhibitory Activities of Organic Extracts of Selected Sri Lankan Bryophytes.

Medicinal plants have been the main focus of natural product research. However, recent research has revealed that lower plants including bryophytes are also a major resource of biologically active compounds with novel structures. Sri Lanka is considered as a biodiversity hotspot with a higher degree of endemism flora including bryophytes. In this study, different species of bryophytes were investigated for their antimicrobial and alpha-amylase inhibitory activities. The air-dried plant materials of 6 different bryophyte species, Marchantia sp., Fissidens sp., Plagiochila sp., Sematophyllum demissum, Hypnum cupressiforme, and Calymperes motley, were subjected to sequential cold extraction with 3 different organic solvents. All three types of organic crude extracts were subjected to screening of antimicrobial bioassays using the disc-diffusion method against 3 bacterial strains and 1 fungal strain. According to the results obtained, 6 extracts out of 18 showed antibacterial activity for tested Gram-positive bacteria and 1 active against Gram-negative bacteria. Two extracts showed activity against the pathogenic fungus strain. Extracts from some plants were active against tested bacterial as well as fungal species. TLC-based bioautographic study was carried out to identify the corresponding active bands which is useful for active compound isolation. Furthermore, the ethyl acetate extracts were subjected to evaluate alpha-amylase inhibitory activity where three extracts out of six extracts showed moderate inhibitory activity for alpha-amylase with IC50 ranging 8–30%.

Effect of Extraction and Drying Method on Chemical Composition, and Evaluation of Antioxidant and Antimicrobial Activities of Essential Oils from Salvia officinalis L.

The present study was carried out to determine, for the first time, the chemical composition, antioxidant and antimicrobial activities of essential oils from leaves of Salvia officinalis L. cultivated in Algeria. The essential oils (EOs) obtained by different extraction techniques: the microwave-assisted hydrodistillation (MAHD), the conventional hydrodistillation (HD) technique and the steam distillation (SD). The volatile compounds were analyzed by gas chromatography flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). The results were compared in terms of extraction time, yield extraction and chemical composition. The effect of drying method on the chemical composition of the essential oil generated by air or by oven drying. The results obtained showed that dried plant material yielded more essential oils than the fresh one. The highest EO yields were obtained for the oven-dried at 60°C (2.5 %) for one day, followed by the air-dried plant material for twenty one days (2.25 %). The chemical analysis of EO led to the identification of 28, 30 and 25 compounds in HD, MAHD and SD oils, respectively. The main components of EO resulting from the different extraction techniques were 1,8-cineole (11.00-12.16 %), α-thujone (15.80-17.92 %), camphor (10.70-23.95 %), α-humulene (4.50-9.61 %) and viridiflorol (9.49-13.10 %). The method of drying induced very significant variations for some compounds, especially for main compounds such as camphor (21.78-25.36 %), α-thujone (16.84-17.40 %) 1,8-cineole (15.15-17.92 %), caryopyllene oxide (5.46-8.42 %). The antioxidant activity evaluated by DPPH (1,1 diphenyl-2picryl-hydrazyl) radical scavenging assay showed an appreciable efficiency. The antimicrobial activity tested on seven microorganisms showed that the EO obtained by SD was remarkably more active, and that Pseudomonas aeruginosa and Candida albicans were resistant to all tested oils.

Essential oil chemotypes of Aloysia citrodora (Verbenaceae) in Northwestern Argentina

Chemical biodiversity of essential oils of natural populations of Aloysia citrodora Palau (“lemon verbena”, “cedrón”) in Northwestern Argentina was assessed by collecting in the same sites through different years. A total of 36 samples were collected in the Provinces of Salta (El Maray, La Paya, El Sunchal, El Alisal, Chorrillos), Jujuy (Chilcayo, San Roque), Catamarca (Mutquin, Colana) and Tucumán (Amaicha del Valle) in Argentina.Essential oils were obtained by hydrodistillation (Clevenger) of naturally air-dried plant material. Yields ranged from 0.16% to 1.93% (v/w), being the highest those of the collections of Mutquin. More than 65 compounds were identified by CG-FID-MS. Only 19 of these constituents, accounting from 77.3 to 98.9% of the total oil, present in more than 4.0% in at least one sample, were considered as variables for statistical analysis. Agglomerative Hierarchical Cluster analysis was conducted, showing at 65% of similarity, five groups. This grouping was in direct accordance to the biosynthetic pathways of main compounds (chemotypes).In the two sites of Jujuy, 21 collections evidenced four different chemotypes, named after the dominant component as follows: thujones, citronellal, carvone, and citral (neral + geranial). In the populations of Salta and Catamarca, linalool appeared as a new different chemotype.Though cedron is considered as a citral-bearing plant, curiously, in the 36 samples collected in the NW of Argentina, only two samples contained citral as main constituent. On the other hand, a dominance of citronellal and thujones compositions were found in the bulk of the samples collected, while others had very high content of linalool or carvone and its derivatives. Northwestern Argentina has repeatedly been mentioned as the center of biodiversity of this species.The new evidences found on the chemical biodiversity of essential oils of Aloysia citrodora in natural populations in this region, reinforce firmly this idea.

Chemical composition and biological activity of Nepeta cilicica

In the present study, aerial parts of Nepeta cilicica were hydro-distilled for the essential oil. Furthermore, air-dried plant materials were extracted with methanol. According to GC-MS results, 35 compounds were characterized in the oil (totally 92%). Caryophyllene oxide, ?-caryophyllene and spathulenol (28.2, 8.9 and 4.2%) were found as main components of the oil. Sixteen compounds were detected by LC/MS, most of which were caffeoylquinic acid, luteolin and apigenin derivatives, in methanolic extract of the N. cilicica. Apart from DPPH radical scavenging activity, inhibitory effects on bacterial and yeast growth of essential oil and the methanolic extract were evaluated. Twenty-four different pathogenic bacterial and Candida strains were tested by M7-A7 and CLSI M27-A2 protocols respectively. The crude extract showed better inhibitory effects against bacteria strains than the essential oil. Both oil and the extract demonstrated strong inhibition on C. tropicalis at a concentration of 47.0 µg/mL (MIC).
 Video Clip of Methodology:
 CLSI microdilution broth method: 3 min 46 sec Full Screen Alternate

PHYTOCONSTITUENTS FROM RICHARDIA SCABRA L. AND ITS BIOLOGICAL ACTIVITIES

Objective: The present chemical investigation is carried out for the isolation of active phytoconstituents from Richardia scabra Linn belongs to Rubiaceae family.Methods: Air dried plant material was macerated with petroleum ether and defatted plant was introduced in Soxhlet apparatus with methanol. Both extracts were subjected to column chromatography for isolation of active chemicals.Result: Two novel coumarins from the methanol extract and one fatty acid from the petroleum ether extract were isolated from Richardia. Oleic acid, heraclenin and isopsoralen were isolated for the first time in the genus Richardia. Furthermore, the cytotoxicity of the heraclenin was evaluated with HeLa cell line and cell cycle arrest by Fluorescent assisted cell sorting analysis.Conclusion: The result revealed that the heraclenin has potent cytotoxicity with the IC50 value was 46.09µg/ml and it induced cell cycle arrest in G0/G1 phase about (51.2%), S phase (30.2) and resulted in a decline in the percentage of G2-M phase.Keywords: cell cycle, cytotoxicity, Heraclenin, isopsoralen, Oleic acid, Richardia scabra

Secondary metabolites of seven Hypericum species growing in Turkey

Context The genus Hypericum (Hypericaceae) has attracted remarkable scientific interest as its members have yielded many bioactive compounds.Objective The current study presents investigations on the accumulation of hypericin, pseudohypericin, hyperforin, adhyperforin, chlorogenic acid, neochlorogenic acid, caffeic acid, 2,4-dihydroxybenzoic acid, 13,118-biapigenin, hyperoside, isoquercitrin, quercitrin, quercetin, avicularin, rutin, (+)-catechin and (−)-epicatechin in seven Hypericum (Hypericaceae) species growing wild in Turkey, namely, H. aviculariifolium Jaup. and Spach subsp. aviculariifolium (Freyn and Bornm.) Robson var. albiflorum (endemic), H. bithynicum Boiss., H. calycinum L., H. cardiophyllum Boiss., H. elongatum L. subsp. microcalycinum (Boiss. and Heldr.) Robson, H. hirsutum L. and H. xylosteifolium (Spach) N. Robson.Materials and methods The plant materials were collected at flowering period and dissected in different tissues. Air-dried plant material including stems, leaves and flowers was mechanically powdered with a laboratory mill and samples (0.1 g) were extracted in 10 mL of 100% methanol by ultrasonication at 40 °C for 30 min for HPLC-PDA analyses.Results Accumulation levels of the investigated compounds varied greatly depending on species and plant part.Discussion For the first time, the detailed chemical profiles of corresponding Turkish Hypericum species were reported and the results were discussed from a phytochemical point of view.Conclusions The present data have importance in evaluation of plant resources of Hypericum genus in selecting the new potential sources of bioactive compounds.

Composition of Essential Oils from the Leaf and Stem Bark of Michelia foveolata

The chemical constituents of essential oils obtained from the hydrodistillation of the leaf and stem of Michelia foveolata Merr. et Dandy (Magnoliaceae) were being reported. The main compounds of the leaf essential oil are β-caryophyllene (37.1%) and bicyclogermacrene (23.3%). However, βcaryophyllene (26.4%), germacrene D (5.9%), trans-α-bergamotene (5.6%), δ-cadinene (5.5%), bicyclogermacrene (5.4%), bicycloelemene (5.3%), spathulenol (5.3%) and 3,7-guaiadiene (5.1%) were present in the stem. Aims: The aim of this study was to isolate essential oils from the leaf and stem bark of Michelia Original Research Article Dai et al.; JSRR, 10(6): 1-6, 2016; Article no.JSRR.25304 2 foveolata Merr. et Dandy (Magnoliaceae) and investigate the volatile constituents present therein. Study Design: The study involves the hydrodisitillation of essential oils from the air-dried plant materials and analysis of their chemical composition. Place and Duration of Study: The leaf and stem bark of M. foveolata were collected from Vũ Quang National Park, Ha Tĩnh Province Vietnam, in July 2014. Methodology: About 500 g of air-dried plant samples was shredded and their oils were obtained by separate hydrodistillation for 4 h at normal pressure, according to the Vietnamese Pharmacopoeia. The chemical constituents of the distilled oils were analyzed by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Results: The main compounds of the leaf essential oil are β-caryophyllene (37.1%) and bicyclogermacrene (23.3%) while the stem bark contained large amounts of β-caryophyllene (26.4%), germacrene D (5.9%), trans-α-bergamotene (5.6%), δ-cadinene (5.5%), bicyclogermacrene (5.4%), bicycloelemene (5.3%), spathulenol (5.3%) and 3,7-guaiadiene (5.1%). Conclusion: The present oil compositions were found to be different from the results obtained previously from the essential oils of Michelia species grown in Vietnam and other parts of the world.

Postharvest changes in essential oil content and quality of lavender flowers

The aim of this study was to analyse both the essential oil (EO) content and quality changes of two Czech Lavandula angustifolia Mill. varieties, ‘Krajová’ and ‘Beta’, in the period between the harvesting and chemical analysis. An eight-year experiment proved that during the long-term storage of dried flowers a gradual reduction in the total content of EO occurs at a rate of about 0.007% per day, which means about 2.56% per year. The content of linalool, terpinen-4-ol, lavandulol, linalyl acetate, α-terpineol, and lavandulyl acetate varied between the varieties. In the case of ‘Krajová’ the value of the correlation coefficient showed a decreasing tendency of terpinen-4-ol, lavandulol, linalyl acetate, and linalool. In the case of the ‘Beta’ variety loss rates for linalyl acetate, lavandulyl acetate, and terpinen-4-ol were found. This can be partly explained by disappearance but also by degradation and rearrangement into other compounds, such as linalool, lavandulool, and α-terpineol, whose content increased. The residual moisture of the air-dried plant material and room temperature are sufficient for the changes in such compounds during long-term storage. Only the differences between the varieties that were tested and growing seasons in terms of the EO content and composition were statistically proven, although it can be assumed that the differences in the EO content and composition between determinations would also be statistically significant in longer-term monitoring. No relationship between the initial EO composition and its loss during storage was found.

Isolation and identification of chemical constituents from Origanum majorana and investigation of antiproliferative and antioxidant activities.

Origanum majorana L., belonging to the Lamiaceae family, has great potential and has been used as a folk medicine against asthma, indigestion, headache and rheumatism; in addition, the essential oils of this plant have been used widely in the food industry. Plant materials have been harvested from the Medicinal and Aromatic Plant Field of Gaziosmanpasa University. Air-dried plant materials were boiled in water, filtered, and the solvent part subsequently extracted with hexane and ethyl acetate. The chromatographic method was applied to the ethyl acetate extract to isolate bioactive secondary metabolites, the structures of which were elucidated by spectroscopic techniques: basically one-dimensional and two-dimensional nuclear magnetic resonance and quadrupole time-of-flight liquid chromatography. Antiproliferative and antioxidant activities of isolated secondary metabolites were determined. 5,6,3'-Trihydroxy-7,8,4'-trimethoxyflavone, hesperetin, hydroquinone, arbutin and rosmarinic acid were isolated from the water-soluble ethyl acetate extract of aerial parts of O. majorana. Antioxidant activities of isolated compounds and water-soluble ethyl acetate extract were investigated using assays of DPPH(•), ABTS(•+), reducing power and total phenolic content. Antiproliferative activities of the isolated compounds and plant extracts were investigated against C6 and HeLa cell lines using BrdU cell proliferation enzyme-linked immunosorbent assay and xCELLigence assay, respectively. Both hesperetin and hydroquinone were determined to have stronger antiproliferative activities against C6 and HeLa cells than the other isolated compounds and 5-fluorouracil. The results showed that the extract and isolated compounds exhibited significant antioxidant activities. Hence this plant has the potential to be a natural antioxidant in the food industry and an anticancer drug.

Analysis of the Essential Oils from Five Vietnamese Litsea Species (Lauraceae)

In this paper, the compositional pattern of essential oils from five plants in the genus Litsea (Lauraceae family) cultivated in Vietnam, were being reported. The air-dried plant materials were hydrodistilled and the oils were analysed by Gas chromatography-flame ionization detector (GC-FID) and Gas chromatography coupled with Mass spectrometry (GC-MS). The leaf oil of Litsea helferi Hook.f., was rich in limonene (17.5 %), β-caryophyllene (14.2 %), bicyclogermacrene (13.1 %), bicycloelemene (12.4 %) and α-phellandrene (8.0 %). The main constituents of Litsea ferruginea Liou., leaf oil were dominated by monoterpenes comprising of sabinene (34.5 %), α-pinene (10.1 %), γ-terpinene (7.8 %), limonene (6.9 %) and terpinen-4-ol (6.6 %). The quantitative significant constituents of the leaf oil of Litsea verticillata Hance were also monoterpene compounds represented by linalool (23.4 %), α-pinene (26.1%) and β-pinene (11.7 %). In addition, the monoterpene hydrocarbons (E)-β-ocimene (57.4 %), along with α-pinene (7.8 %) and β-pinene (7.3 %) were the main constituents in the leaf oil of Litsea glutinosa (Lour.) C. B. Rob. The main compounds in the leaf, stem, fruits and roots oils of Litsea cubeba (Lours.) Pers., were (Z)-citral (32.9-66.1 %), sabinene (1.4-14.2 %), limonene (7.0-13.6 %) and linalool (1.9-9.5 %). The chemical compositions of L. helferi, L. ferruginea and L. verticillata are being reported for the first time.

Antimicrobial Qualities of Senna Alata

The antimicrobial activity of the root and leaf extracts of the Senna alata plant against some infectious bacteria (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa etc) and fungi (spergillus flavus, Aspergillus niger, Candida albicans etc) as well as the physiochemical and microbiological quality of the plant was determined using the cup plate agar diffusion method. The freshly collected fresh mature leaves and roots were chopped into pieces and shade-dried at 32-35 0 C to constant weight for 5 days. 50g each of the plant parts was coarsely powdered using a mortar and pestle and finely powdered using an electric blender. Each of the powdered air-dried plant material was extracted with water, acetone and methanol. All the extracts demonstrated considerable activity against both Gram negative and Gram positive bacteria and some fungi with the organic extracts showing higher activity than the aqueous extracts. Stretococus pyogenes and S. aureus were the most susceptible to all the extracts followed by Salmonella typhi and Escherichia coli. The most susceptible fungi were Cryptococcus neoformans and Candida albicans while the least susceptible was Aspergillus flavus. The minimum inhibitory concentration and minimum bactericidal concentration of the methanol extracts ranged between 3-10 mg/ml and 25-50 mg/ml for bacteria and fungi respectively. Preliminary phytochemical analysis showed that the extracts contained tannins, saponins, glycosides, flavonoids and phenols. The results obtained show the basis for the local usage of S. alata Linn as an antimicrobial. Phytochemical result showed ethanol to be a better solvent for the extraction of the bioactive agents in Senna alata which include: glycosides, alkaloids, saponins, tannins, flavonoids and volatile oil. Despite the significant progress made in microbiology and the control of microorganisms, sporadic incidents of epidemics due to drug resistant microorganisms pose an enormous threat to public health. The use of medicinal plants for antimicrobial activities needs to be given more attention.