Functional characterization of sll0659 from Synechocystis sp. PCC 6803.

Synechocystis sp. PCC 6803 lacks a gene for the any known types of lycopene cyclase. Recently, we reported that Sll0659 (unknown for its function) from Synechocystis sp. PCC6803 shows similarity in sequence to a lycopene cyclase gene-CruA from Chlorobium tepidum. To test, whether sll0659 encoded protein serves as lycopene cyclase, in this study, we investigated the carotenoids of the wild types and mutants. In the sll0659 deleted mutant, there is no blockage at the lycopene cyclization step. Our results demonstrate that sll0659 does not affect lycopene cycilzation. However, the ultrastructure of mutants suggests the involvement or necessity of sll0659 in the cell division.

Antioxidant property of Decalepis hamiltonii Wight & Arn.

Aromatic edible root of D. hamiltonii was subjected to the extraction of the antioxidant rich fraction. Different parts of root namely whole tuber, peel, tuber without peel and medullary portion were extracted with dichloromethane (European Patent No. W02005063272). The extract was found to contain flavor compound 2-hydroxy-4-methoxybenzaldehyde (2H4MB), which was identified by TLC and GC. Medullary portion was found to be rich in 2H4MB, (73.73 mg g(-1) dry tissue) followed by peel, containing 68.34 mg g(-1) 2H4MB. Different concentration of dichloromethane extracts were subjected for antioxidant assay by DPPH (1,1 dihydroxy 2-picryl hydrazyl) method, this has shown 44, 46.7% radical scavenging activity in case of medullary, peel extracts and 67.3% in case of pure 2-hydroxy-4-methoxybenzaldehyde at 100 ppm concentration, whereas ascorbic acid used as standard showed 94.3% activity. In beta-carotene linoleate model system (b-CLAMS) 43.46 and 45.7% antioxidant activity was observed in medullary and peel extracts at 100 ppm concentrations respectively, whereas standard 2-hydroxy-4-methoxybenzaldehyde exhibited 69.64% at 100 ppm and BHA (butylated hydroxyl anisole) 90.1% activity also at 100-ppm level. Similarly hydroxyl radical scavenging activity was found to be 48.36, 46.86, 48.26 and 73.60% in whole tuber, medullary, peel and standard 2-hydroxy-4-methoxy benzaldehyde respectively at 100 ppm levels. This is the first report on the antioxidant activity of D. hamiltonii. Results have shown that 2H4MB is one of the major constituents responsible for antioxidant activity. Hence the extract of D. hamiltonii can be utilized for the production of antioxidant rich fractions required for various health benefits.

Intake of Dietary Fat and Vitamin in Relation to Breast Cancer Risk in Korean Women: A Case-Control Study

To investigate association between breast cancer risk and nutrients intake in Korean women, a case-control study was carried out, at Seoul, Korea. Incident cases (n=224) were identified through the cancer biopsy between February 1999 and December 2000 at two University hospitals in Seoul. Hospital-based controls (n=250) were selected from patients in the same hospitals, during the same periods. Food intake was investigated semiquantitative frequency questionnaire (98 items) by trained dietitian. Subjects were asked to indicate the average food intake and vitamin supplement for a 12 months period of 3-yr prior to the base-line phase. In investigation of vitamin supplement use, subjects were asked the average frequency of use, duration, dose and the brand name of vitamin supplement (multivitamins, vitamin A, vitamin C and vitamin E). And nutrients were calorie adjusted by the residuals method. In this study, higher breast cancer risk incidence was not observed with higher intake of total fat and saturated fatty acids, however statistically significant trends with breast cancer incidence for total saturated fatty acids were found (p trend =0.0458). In analyses of vitamins, beta-carotene and vitamin C were significantly associated with decreasing risk of breast cancer. In analyses, results from dietary plus supplement of vitamin was not associated with breast cancer risk in this study. In conclusion, our findings suggest that antioxidant vitamins such as beta-carotene and vitamin C intake could lower the breast cancer risk in Korean women.