Antibacterial activity of chrysophanol isolated from Aloe excelsa (Berger)

Extraction of the yellow colour compounds of leaves of Aloe excelsa were performed and 1,8-dihydroxy-3-methylanthracenedione (chrysophanol) was isolated and tested for antibacterial activities against four gram negative and five gram positive bacterial strains. The structures of chrysophanol was determined by chemical spectroscop

Traditional use, antibacterial activity and antifungal activity of crude extract of Aloe excelsa

The fleshy leaves and roots of most species within the Aloe family are used in many traditional treatments (Mabberley, 1987). Traditional healers and indigenous people utilize mainly the leaf sap of this genus widely for the treatment of wounds, burns, rashes, itches, cracked lips and cracked skin(Cera et al., 1980). Antimicrobial activities on the crude extract of Aloe exclesa was carried out in attempts to validate the use by traditional healers in the use of there latex and gel exudates for various medicinal ailments

Antibacterial activity of aloe emodin and aloin A isolated from Aloe excelsa

Different extracts of leaves of Aloe excelsa were prepared and two compounds; 1,8-dihydroxy-3-hydromethyl-9,10-antracenedione and 10-C-b-D-glucopyranosyl-1,8-dihydroxymethyl-9-anthracenone, were isolated and tested for antibacterial activities against four Gram negative and five Gram positive bacterial strains. The structures of the two compounds were determined by chemical spectroscop

Variation in the essential oil constituents of Pteronia incana (Asteraceae)

The essential oil of Pteronia incana was collected and was investigated on a monthly basis using GCMS. The oil volume and its constituents vary greatly with different time of sampling and distillation. The oil contains a high percentage of myrcene a-pinene, b-pinene with sabinene, a-terpinene, 1.8 cineole and limonene

Chemical composition of volatile constituents from the leaves of Aloe ferox

Volatile compounds oils play a significant role in perfumery, cosmetic, medicinal and pharmaceutical industries. In our protracted research for new useful essential oils, a volatile oil from Aloe ferox was obtained by prolonged hydrodistillation. This volatile oil was subjected to GC/MS analysis to identify the major constituents of the oil. The major constituents identified were as follows: 3, 6 octatriene (23.86%), 3-cyclohexane-1-hetanol (7.31%), Bornylene (5.24%), 1, 3-cyclopentadiene (4.07) and 5-methyl- 3-heptanol (3.92%). A significant number of other volatiles were also identified but in minor concentrations

The chemical composition and biological activities of essential oil from the fresh leaves of Schinus terebinthifolius from Zimbabwe

In the present study, the essential oil from the fresh leaves of Schinus terebinthifolius was extracted using the hydrodistillation method. The oil yield obtained was 0.65%. Gas chromatography and mass spectroscopy (GC-MS) analysis of the essential oil showed that the major constituents of the essential oil were sabinene, -pinene, -phellandrene, -pinene, terpinene-4-ol, trans--ocimene and myrcene. Using the hole-plate diffusion testing method, the essential oil exhibited potent antibacterial activity against Yersinia enterocolitica, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter calcoaceticus, Bacillus subtilis, Klebsielia pneumoniae and Bacillus subtilis with at least 58% inhibitioncompared to the positive control. The mycelium growth inhibition method was used for anti-fungal testing. The essential oil exhibited activity against Aspergillus flavus with 58% inhibition, Candida albicans with 49.8% inhibition and Aspergillus niger with 48.7% inhibition. The -carotene, acetone and linoleic acid method was used to assess the antioxidant activity of the essential oil. The essential oil showed anti-oxidant activity of 13.1 mm mean zone of colour retention representing 72.7% activitycompared to the positive control (ascorbic acid). This is the first study on S. terebinthifolius collected from sub-saharan Africa indicating the presence of trans--ocimene in the essential oil and its strong antibacterial activity against Y. enterocolitica and P. aeruginosa as well as moderate antifungalactivities of the plant

Analysis of a gum from the exudates of Dichrostachys cinerea (L.) Wight & Am

Only little research is currently underway on gums from African plants, yet Africa imports a lot of gums for pharmaceutical and food industries. This study was aimed to investigate the rheological properties, and the moisture and ash contents of the isolated gum resins from Dichrostachys cinerea. The gum from this plant exhibited low shear stress even at high concentrations of the gum. The moisture content obtained was 15.8 ± 0.3%, which was rather too high and would only be suitable for formulations that need to remain moisturized. The gum from this plant had little ash content (2.59 ± 0.01%). The gum from D. cinerea exhibited low shear stress at high concentrations, while the gum was profoundly affected by the addition of ions. In conclusion, this gum has potential as a product for the cosmetic, pharmaceutical and food industries. Further studies are needed to identify the phytoconstituents in the gum as well as toxicity studies.Key words: Gum, exudates, Dichrostachys cinerea, rheology, moisture

Aphrodisiac properties of some Zimbabwean medicinal plants formulations

The aim of the present study was to determine the effects of formulations composed of Mondia whitei, Ekebergia capansis, aloe tincture (Aloe exelsa) and pumpkin seed (Cucurbita pepo) on sexual behaviour of inexperienced male rats. Male rats were treated orally with ethanol extracts of M. whitei and E. capensis, aloe tincture (from aloe juice) and pumpkin seed powder. The sexual behaviour of the rats treated with extracts was compared with those treated with 100 ìg of testosterone as the positivecontrol and those receiving normal rat feed as negative control. The receptivity of the females was rendered homogeneous with daily dose of estadiol benzoate. The sexual behaviour of the rats were observed over one ejaculatory phase for five consecutive days. The results showed a dose dependent increase in sexual arousability (decreased mounting latency), copulatory efficiency (decreased intercoupulatory interval) and improved sexual sensation (increased in neuromotor activity) for the ratstreated with M. whitei and E. capensis, aloe and pumpkin seeds showing an increase in sexual performance in terms of intromissions and ejaculatory latency which also improved sexual sensation and coupulatory efficiency. The formulations of plants under investigation showed significantaphrodisiac properties

The essential oil composition and antimicrobial activity of leaves of Schistostephium hippifolium

The essential oil from the leaves and branches of Schistostephium hippifolium were extracted by hydro-distillation during summer and winter months. Both essential oils were analyzed by gas chromatography- mass spectroscopy (GC-MS) respectively during their extracted period. Fourteen compounds were  identified from essential oil extracted during the February, summer month in South Africa. The volatile oil constituted about 99.31% of the total essential oil composition. The GC-MS reveals the following major constituents in the oil: Chrysanthenyl acetate (32.17%), 1.8-cineole (24.85%), ethanone, 1-  (1-cyclohexen-1-y1) (6.36%), camphor (6.02%), terpinen-4-ol (5.02%), á-pinene (5.13%),  germacrene-D (4.89%) bicyclogermacrene (4.38%), linalool L (2.04%), trans - caryophyllene (1.80%), ã-terpinene (1.95 %). In June, a winter month in South Africa, 48 volatile compounds from the essential oil of S. hippifolium were identified which constituted about 99.99% of the total composition of the  essential oil. The major compounds identified were the 1.8-cineole (18.31%), Germacrene-D (7.43%), bicyclogermacrene (5.24%), 3-cyclohexen-1-ol (6.78%), camphor (5.64%), bicyclogermacrene  (5.24%), á.-pinene (2.52%), â-caryophylle (2.11%), linalool L (3.35%), caryophyllene oxide (1.88%), spathulenol (1.62%) and ã-terpinene (1.39%). In both essential oils (summer and winter), minor volatiles were identified. However, they were in low concentration. The crude extract from the aerial parts of the plant were screened for antibacterial activity against five Gram-positive species  (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Micrococcus kristinae and Staphylococcus faecalis) and five Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Staphlococcus flexneri, Klebsiella pneumonia and Serratiaf marcescens) microorganisms. The minimum inhibitory concentration (MIC) values where highly active at values below two and less active at values above two. All the extracts tested displayed very good activity against both Gram-positive and  Gram-negative bacteria with MIC ranging between 0.098 to 0.65 mg/l.Key words: Essential oil, GC-MS, oil composition, antimicrobial activity, Schistostephium hippifolium