Antiproliferative Acylated Glycerols from New Zealand Propolis.

Previous work has shown that a number of phenolic components of NZ propolis possess antiproliferative activity against certain human gastrointestinal cancer cell lines. Here we report on a series of acylglycerols isolated from the nonpolar fraction of propolis resin, which represent further bioactive constituents unrelated to the more usual phenolic compounds generally found in propolis. NZ propolis is sourced from poplar trees, and the acylglycerols have been shown to be present in the leaves and buds of some common poplars. The compounds are a series of monoglycerides containing 3,8-dihydroxy fatty acids, many of which are further acylated with acetic acid residues. The dihydroxy fatty acids are C18 to C24, with the most abundant being C20 and C22. These acylglycerols were found to have strong antiproliferative activity against three human gastrointestinal cell lines, particularly gastric cancer cell line NCI-N87, where one example shows an IC50 of less than 50 µM.

Antiproliferative activity of New Zealand propolis and phenolic compounds vs human colorectal adenocarcinoma cells.

New Zealand propolis is a "European" type propolis obtained by honey bees mainly from exudates of poplar. European type propolis is known to have anti-inflammatory and anti-cancer properties and this activity has been attributed to some of the main constituents such as chrysin and CAPE (caffeic acid phenethyl ester). As part of our studies on how New Zealand propolis might benefit gastro-intestinal health, we carried out in vitro bioactivity-guided fractionation of "Bio30™" propolis using both anti-inflammatory (TNF-α, COX-1, COX-2) and anti-colon cancer (DLD-1 colon cancer cell viability) assays; and determined the phenolic compounds responsible for the activity. The New Zealand wax-free Bio30™ propolis tincture solids had very high levels of the dihydroflavonoids pinocembrin and pinobanksin-3-O-acetate, and high levels of the dimethylallyl, benzyl and 3-methyl-3-butenyl caffeates relative to CAPE. The DLD-1 assays identified strong anti-proliferative activity associated with these components as well as chrysin, galangin and CAPE and a number of lesser known or lower concentration compounds including benzyl ferulate, benzyl isoferulate, pinostrobin, 5-phenylpenta-2,4-dienoic acid and tectochrysin. The phenolic compounds pinocembrin, pinobanksin-3-O-acetate, tectochrysin, dimethylallyl caffeate, 3-methyl-3-butenyl caffeate, benzyl ferulate and benzyl isoferulate also showed good broad spectrum activity in anti-proliferative assays against three other gastro-intestinal cancer cell lines; HCT-116 colon carcinoma, KYSE-30 oesophageal squamous cancer, and NCI-N87 gastric carcinoma. Activity is also observed in anti-inflammatory assays although it appears to be limited to one of the first cytokines in the inflammatory cascade, TNF-α.

Supercritical fluid assisted, integrated process for the synthesis and separation of different lipid derivatives.

The partial synthesis of ethyl esters from corn and fish oil was carried out in a stirred tank at supercritical conditions and the products were separated from the reaction mixture using the supercritical fluid. Corn oil can be almost completely converted to ethyl esters under optimized conditions and the rate of reaction is comparable to atmospheric pressure conditions. Some concentration of polyunsaturates occurs in the partially converted glyceride fraction of fish oil, as the enzyme used, Lipozyme TL-IM, allows preferential esterification of the saturates and mono-unsaturates that are concentrated in positions 1 and 3 of the triglycerides. By judicious selection of the processing conditions, good separation of ethyl esters from the partially reacted glycerides was achieved.

Extraction of chili, black pepper, and ginger with near-critical CO2, propane, and dimethyl ether: analysis of the extracts by quantitative nuclear magnetic resonance.

Ginger, black pepper, and chili powder were extracted using near-critical carbon dioxide, propane, and dimethyl ether on a laboratory scale to determine the overall yield and extraction efficiency for selected pungent components. The temperature dependency of extraction yield and efficiency was also determined for black pepper and chili using propane and dimethyl ether. The pungency of the extracts was determined by using an NMR technique developed for this work. The volatiles contents of ginger and black pepper extracts were also determined. Extraction of all spice types was carried out with acetone to compare overall yields. Subcritical dimethyl ether was as effective at extracting the pungent principles from the spices as supercritical carbon dioxide, although a substantial amount of water was also extracted. Subcritical propane was the least effective solvent. All solvents quantitatively extracted the gingerols from ginger. The yields of capsaicins obtained by supercritical CO(2) and dimethyl ether were similar and approximately double that extracted by propane. The yield of piperines obtained by propane extraction of black pepper was low at approximately 10% of that achieved with dimethyl ether and CO(2), but improved with increasing extraction temperature.