Two new triterpenoid glycosides, together with two new ergostane glycosides, umbellatosides A -D (1 -4, resp.), have been isolated from the leaves of Hydrocotyle umbellata L. Their structures were established by 2D-NMR spectroscopic techniques ( 1 H, 1 H-COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3b,22b-dihydroxy and (3b,11a,21,26)-ergosta-5,24(28)-diene-3,11,21,26-tetrol Introduction. -The genus Hydrocotyle (Apiaceae) is constituted by aquatic or semiaquatic plants particularly well represented in temperate areas and higher tropical regions [1]. Some species were reported to have antioxidant and antitumoral properties [2] [3]. Triterpene saponins were isolated from several species of this genus [4 -7]. From H. umbellata, a herbaceous plant native to North America and parts of South America, this compound type has not been reported so far. In our continuing search for bioactive saponins from tropical plants, we report here the isolation and structure elucidation of two new triterpene saponins and two new ergostane glycosides, named umbellatosides A -D (1 -4, resp.), from the 70% MeOH extract of the leaves of H. umbellata.

The essential oil from fresh leaves of Croton ovalifolius Vahl was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). Twenty‐eight compounds, which represent 90.4% of the total constituents of the oil, were identified. The most abundant constituents were β‐caryophyllene (20.8%), bicyclogermacrene (12.1%), germacrene B (10.7%),τ‐cadinol (8.1%), spathulenol (6.0%) and caryophyllene oxide (5.2%). Copyright © 2000 John Wiley & Sons, Ltd.

In previous papers 1,2) we have described several compounds, mainly sesquiterpenoids, isolated from the resin of Trattinickia rhoifolia WILLD. (Burseraceae). In this paper we report the isolation and structure elucidation by spectroscopic methods and X-ray diffraction analysis of biatractylolide (1). Results and DiscussionTo the solution of resin of T. rhoifolia in methylene chloride, n-hexane was added to selectively precipitate and separate the insoluble material; the soluble part was taken to dryness and redissolved in diethyl ether, then washed with aqueous sodium bicarbonate (5% w/v) to remove the acidic compounds. Elimination of the solvent yielded an oily mixture, which was resolved by silica gel column chromatography using increasing gradient n-hexane-ethyl acetate mixtures as eluent. After column rechromatography on silica gel using an increasing gradient of n-hexane-methylene chloride as eluent, low polarity fractions afforded, along with other previously reported compounds, 3) the bis [8-eudesma-4(15)