STEROIDAL CONSTITUENTS AND A FATTY ACID ESTER FROM THE FRUIT PEELS OF CITRUS SINENSIS (L.) OSBECK

Citrus sinensis (L.) Osbeck (Rutaceae), is distributed in tropical and temperate regions of India, China, Mexico, Congo and East Africa. Its fruit peel is carminative, stomachic, tonic and is used to cure acne, earache, anorexia, colds, coughs and toothache. The essential oil is antiseptic, anti-inflammatory and effective to relieve bronchitis, colic, constipation, cramps, depression, fluid retention, gastritis, motion sickness, mouth ulcers, nervous tension, obesity, and stress. The phytochemical investigation of a methanolic extract of the fruit peels of C. sinensis afforded three new compounds, characterized as 11′β-hydroxyl-n-octadecanyl n-hexacosanoate (11′ β-hydroxyl-n-octadecanyl cerotate, 1), stigmast-5-en- 3α-ol-23-one (sinensisterol, 3) and β-sitosterol-3-O-β-D-glucopyranosyl-2′-laurate (β-sitosterol glucosyl laurate, 5) together with the known compounds n-hexacosanoic acid (cerotic acid, 2) and stigmasterol 3-O-β-D-glucoside (4). The structures of the isolated phytoconstituents were established on the basis of spectral data analysis and chemical reactions.

Hyper-Elongation in Colorectal Cancer Tissue – Cerotic Acid is a Potential Novel Serum Metabolic Marker of Colorectal Malignancies

Backgrounds/Aims: Colorectal cancer (CRC) cells show some alterations of lipid metabolism. Elongation of fatty acids (FA) has not been studied in CRC tissues thus far. The aim of this study was to verify if CRC specimens and normal colon mucosa differ in terms of their levels of very long-chain FAs, a product of FA elongation. Moreover, the expression of elongase genes has been studied in normal tissue and CRC. Finally, we searched for some specific products of FA elongation in serum of CRC patients. Methods: The specimens of normal colon mucosa and CRC were obtained from nineteen CRC patients differ in terms of FA elongation. We also searched for some specific products of FA elongation in serum of CRC patients and from healthy volunteers. Tissue and serum FA profiles were determined by means of gas chromatography-mass spectrometry (GC/MS), and the tissue expression of elongases (ELOVLs) was analyzed with real-time PCR. Results: Compared to normal colon tissue, CRC specimens showed significantly higher levels of 22-, 24- and 26-carbon FAs, stronger expressions of ELOVL1 and ELOVL6 (4- and 9-fold elevated respectively), and higher values of 18: 0/16: 0 elongation index. We also demonstrated presence of cerotic acid (26: 0) in serum of all CRC patients but in none of the healthy controls. Conclusions: CRC tissue seems to be characterized by enhanced FA elongation (hyper-elongation). Presence of cerotic acid in CRC patients sera and absence of this FA in healthy subjects points to this compound as a strong candidate for specific metabolic marker of colorectal malignancies.

NEW PHYTOCONSTITUENTS FROM ORYZA SATIVA L. BRAN

Rice bran serves as an important functional food that has cholesterol-lowering and immunostimulating properties, cardiovascular health benefits and antitumor activity. Phytochemical investigation of a methanolic extract of rice bran gave three new phytoconstituents, characterised as 4,4,8β-trimethyl- 9-[13β,17β,21β-trimethyltridec-9(11)-enyl]-decalin-1-en-6-one-3β,27-olide (orizatriterpenolide, 4), β-Dxylopyranosyl- 1,2-dioleiate (1,2-dioleiyl-β-D-xyloside, 6) and ricinoleic acid-12-β-D-glucopyranoside (ricinoleic acid-5-O-β-D-glucoside, 7) together with the known compounds palmitic acid (1), stigmasterol (2), cerotic acid (3) and oleiyl-β-D-arabinopyranoside (5). The structures of all the isolated phytoconstituents were elucidated on the basis of the spectral data analysis and chemical reactions. The compounds 4 (triterpenic lactone), 5 (xylose diester) and 7 (ricinoleic acid-5-O-β-D-glucoside) were isolated for the first time from rice bran.