Royal jelly is a secretion from the hypopharyngeal and mandibular glands of worker bees, and it is the exclusive food of the queen bee for the entire span of both her larval and adult lives. With regard to the constituents of this material, it contains remarkably high amounts of organic acids in the total lipid fraction.1) Many organic acids mainly consisting of 8 to 11 carbon atoms such as 10-hydroxy-2-decenoic 2,3) and 10-hydroxydecanoic acids have been isolated. Among them, a minor component, 9-hydroxy-2-decenoic acid, 4) is known to be a queen honeybee pheromone with swarm-stabilizing activity, 5) and it is also regarded as a precursor of the so-called queen substance, 9-keto-2-decenoic acid, which controls the caste of honeybee colonies.6) Recently, we have isolated mono-or diesters of 10-hydroxy-2-decenoic acid in which the hydroxyl group was esterified by another organic acid residue from the total lipid fraction of the royal jelly of the honeybees (Apis mellifera). 7) In view of these findings, it seems that other unknown compounds including pheromones or their precursors exist in royal jelly. The present study was undertaken to examine the constituents of royal jelly in the hope of discovering the biologically active compounds that control the hierarchy of honeybee colonies. By application of the recycling HPLC technique for the isolation of minor constituents from a complex mixture, two glycosides (1, 2) together with 16 compounds (3-18) were obtained in the pure state. The former two were fatty acid monoglucosides and the latter were sterols mainly composed of 28 or 29 carbons. This paper deals with the isolation and structural elucidation of these compounds. Results and DiscussionThe total lipid fraction obtained from lyophilized royal jelly powder (6.0 kg) was separated repeatedly on silica gel column chromatography with a mixture of CHCl 3 -MeOH to yield crude glycoside and sterol fractions (see Experimental). Both fractions were further separated with HPLC including a recycling mode, and two (1, 2) from the former and 16 (3-18) compounds from the latter were isolated in pure form. Among them, compounds 7-18 were identified as the known sterols 24-methylenecholesterol (7), 8) isofucosterol (8), 9) cholesta-5,24(24Ј)-dien-3b-ol-7-one (9), 10,11) cholesta-5,24(24Ј)-diene-3b,7b-diol (10), 10,12) cholesta-5,24(24Ј)-diene3b,7a-diol (11), 10,12) b-sitosterol (12), 13) stigmast-5-en-3b-ol-7-one (13), 13) stigmast-5-ene-3b,7b-diol (14), 13) stigmast-5-ene-3b,7a-diol (15), 13) cholest-24(24Ј)-ene-3b,5a,6b-triol (16), 14) stigmastane-3b,5a,6b-triol (17), 15) and desmosterol (18) 16) by comparison of their 1 H-and 13 C-NMR spectroscopic data with those described in the literature. Structures of Compounds 1 and 2 Negative-ion FAB-MS of 1 gave an [MϪH]Ϫ ion peak at m/z 347, and HR-FAB-MS revealed the molecular formula of 1 to be C 16 H 28 O 8 . The 1 H-NMR spectrum showed one anomeric proton signal at d 4.87 ppm, in addition to typical signals ascribable to a 10-hydroxy-2-decenoyl group. 7) Based on the couplin...

The present work characterizes novel FA in the royal jelly of honeybees (Apis mellifera). TLC analysis showed that the chloroform/methanol extract obtained from royal jelly consists mainly of FA. The FABMS spectrum of this extract gave several ion peaks due to compounds with higher M.W. than those of the FA so far reported. The methanol extract was found to contain unknown phospholipids. By means of reversed-phase HPLC with various solvent systems, 13 compounds were obtained in pure state. Their structures including absolute configurations were determined by chemical, NMR, and MS spectral analysis. Six compounds were identified as novel mono- or di-esters of 10-hydroxy-2E-decenoic acid in which the hydroxyl group was esterified by another FA unit, and one was hydroxy-2E-decenoic acid 10-phosphate. In addition, we demonstrated that 9-hydroxy-2E-decenoic acid exists as a mixture of optical isomers.

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