[Study on Chemical Constituents from Hypocotyls of Mangrove Bruguiera gymnorrhiza].

OBJECTIVE: To study the chemical constituents from the hypocotyls of mangrove Bruguiera gymnorrhiza. METHODS: The chemical constituents were isolated and purified by recrystallization, silica gel column chromatography and semi-preparative HPLC. Their structures were identified by spectroscopic analysis and comparison with literatures. RESULTS: Seven compounds were isolated and their structures were identified as 3-ß-(Z)-coumaroyllupeol (1), dioslupecin (2), cholesterol (3), menisdaurillide (4), aquilegiolide (5) vomifoliol (6) and roseoside II (7). CONCLUSION: Compounds 1,2 and 4 - 7 are isolated from this plant for the first time.

[Laser tweezers Raman spectroscopy analysis of cold-adapted aromatic hydrocarbons-degradating strains isolated from Antarctic Sea].

Laser tweezers Raman spectroscopy can help with observing and studying individual cells or organelles in a natural state for a relatively long period. In the present experiment, Laser tweezers Raman spectroscopy (LTRS) was used as a tool to report physiological metabolism such as cells growth and nucleic acid, proteins, lipid and glucose of a single active cold-adapted Aromatic hydrocarbons-degradating strains isolated from Antarctic Sea. After the Raman spectrum was collected and analyzed, the findings are as follows: Raman spectrum identified the components of a single cold-adapted Aromatic hydrocarbons-degradating strain and there were more proteins and carbohydrate produced during the Planococcus sp. NJ41 and Shewanella sp. NJ49 growth and degradation; but there was more lipid than the proteins produced during the Pseudoalteromonas sp. NJ289 growth and degradation; the amount of proteins produced by the strains corresponds with the production of degradation rate-limiting enzyme, and was also related to the capacity of low-temperature degradation of aromatic hydrocarbons.

[Raman micro-spectroscopy of single blood platelets].

The authors collected the Raman spectra of single blood platelets of human, pig, rat and rabbit suspended in saline so-lution by using a laser tweezers Raman spectroscopy (LTRS) setup. A single platelet cell was trapped in the focus of a near-infrared laser beam at 785 nm and the excited Raman spectrum was acquired. For each species, the Raman spectra of up to 20 platelet cells were acquired and were used to perform a principal components analysis (PCA) or a discriminate function analysis (DFA). The average Raman spectra indicate that the vibration bands at 1 524 and 1 157 cm(-1) of human platelets are obviously different from those of the platelets from pig, rat and rabbit. The Raman intensities at 1 157 and 1 524 cm(-1) bands are significantly high for human platelets. The ratio I1 157 / I1 003 of human platelets was 0.795, but those of pig, rat and rabbit were 0.532, 0.502 and 0.485, respectively. In addition, the platelets from four different species can be discriminated with multivariate analysis. These findings demonstrate that the LTRS, combined with multivariate analysis, could be used to rapidly discriminate platelets from various species and may find valuable application in rapid sensing of biochemical changes in a single cell.

[Study of Raman spectra of single carcinoma of nasopharynx cell].

The Raman spectra from carcinoma of nasopharynx cell lines (CNE2) and normal airway epithelial cell lines (HBE) were investigated using a laser tweezers Raman spectroscopy (LTRS). The Raman scattering measurements were obtained from three different places in every single cell. Visual inspection of the spectra shows that the differences observed in spectra of the cancer cells and normal cells are obvious. The peak ratio I1 304/I1 336 is 1.05 for the normal cell and 1.22 for the cancer cell. Using a combination of principal component analysis (PCA) and discriminant function analysis (DFA), the authors are able to predict cancer cells, and normal cells and the DFA is better for single Raman spectrum. The sampling locations did not seriously affect the result of PCA and DFA. PCA and DFA also show that the uniformity of normal cells is better than that of cancer cells. The results indicate that the Raman spectra may offer the experimental basis for colorectal cancer diagnosis.