| Osbeckia crinita Benth., which belongs to Melastomataceae, is a common traditional Chinese medicine, and has been recorded in many articles. It has the effect of reducing fever, anti-bacterial, anti-inflammation, liver-protective, anti-cancer and so on. So, it has a tremendous potential development. From the whole plant of O. Crinita, five compounds were isolated using various methods, including silica gel comlumun, prepartive TLC, recrystal and so on. Structures of five compounds were identified by means of spectroscopy methods (1H -NMR, 13C -NMR, DEPT, etc.).Elsholtzia fruticosa (D.Don) Rehd., which belongs to Labiatae, has the effect of dispelling wind and removing obstruction in the meridians, treating athlete's foot, scabies and so on. The chemical compositions of essential oils obtained by hydrodistillation from different organs of E. fruticosa were separately analyzed and identified by the GC-MS and the Kovats retention indext. The biological activities of essential oil and various extracts from leaves were studied primarily.The main results were as follows:(1) Five compounds were isolated from O. Crinita. CompoundⅠ, 184.1 mg, white slice crystals, and can readily dissolved in chloroform. CompoundⅡ, 69.9 mg, white powder, can dissolved in chloroform. CompoundⅢ, 181.8 mg, white needle-like crystals, can dissolved in pyridine, DMSO, and lightly soluble in chloroform, methanol, acetone. CompoundⅣ, 71 mg, yellow powder, can easily dissolved in pyridine, DMSO, and lightly soluble in chloroform, methanol. CompoundⅤ, 67.8 mg, white slice crystals, can dissolved in methanol. Now, the five compounds'structure are being identified according to 1H-NMR, 13C-NMR and DEPT spectrum.(2) 24, 33 and 42 components were separately identified from stems, leaves and flowers of E. fruticosa, respectively. The components and relative contents of the leaves were similar with the flowers, and the main constituents were 1,8-cineole (21.9%, 24.73%), caryophyllene (8.79%, 8.51%),γ-terpinen (4.57%, 5.11%) and so on. The components of the stems were different from others, and the main constituents were hexadecanoic acid (65.05%), phytol (2.75%) and caryophyllene (2.53%).(3) This paper also examined the in vitro antimicrobial activities of the essential oil and various extracts (methanol extract and water extract) of E. fruticosa. Two different methods were employed for the determination of antimicrobial activities: disc diffusion method for the essential oil and agar well-diffusionmethod for the extracts. Results showed that the essential oil and methanol extract were found to possess stronger antibacterial activities than water extract. But they were inactive about yeasts. Among them, the essential oil has the highest inhibition to Klebsiella pneumoniae subsp. Pneumoniae, and the diameter of inhibition zone is (17.60±0.35) mm, which is equivalent to tetracycline hydrochloride (18.50±0.21) mm, followed by Escherichia coli (16.84±0.65) mm and Bacillus subtilis (15.50±1.49) mm. 10 and 7 bacterias were separately sensitive to the methanol extract and water extract, and the Staphylococcus epidermidis was the most sensitive to both extracts, the diameter of inhibition zone is (25.23±1.88) mm and (21.20±0.74) mm, which were biger than the post control (12.80±0.41)mm.(4) The essential oil and various extracts were also subjected to screening for their possible antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) andβ-carotene-linoleic acid assays. In DPPH assay, the free radical scavenging activity of the methanol extract from leaves was superior to water extract (EC50 = 0.014 mg/mL), which was close to the synthetic antioxidant BHT (EC50 = 0.011 mg/mL), while the oil was less effective. In the case of the linoleic acid system, oxidation of the linoleic acid was effectively inhibited by the methanol extract from leaves with 89.67% of inhibition. Results showed that E. fruticosa had a great range of potential utilities and a prospect of development, and it worth further study. |
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