An investigation of the seeds of Swietenia macrophylla and S. aubrevilleana (Meliaceae) is reported. Three new compounds, augustineolide (1) and 3beta,6-dihydroxydihydrocarapin (2) from S. macrophylla and 6-acetoxyhumilinolide C (3) from S. aubrevilleana were isolated and characterized along with fifteen known compounds. Four of the compounds were subjected to an antifeedant bioassay on the final instar larvae of Spodoptera frugiperda. The antifeedant activity was comparable to that of bicyclononanolides previously tested.

ABsmcr.-Erythpodium c u r i b m m obtained off the coast of Tobago has yielded the known diterpenes erythrolide A 111, erythrolide B 121, and erythrolide E 137 as well as a new diterpene designated erythrolide J [4]. T h e structure of compound 4 was determined by high resolution nmr studies.Well over one hundred diterpenes possessing the briarane skeleton have been isolated from marine coelenterates mainly from the sub-class Octocorallia (1). Recent reports of seven new compounds of this type from Erytbropodium caribaemm Duchassaing & Michelotti (Gorgonidae) and nine from a Briareum sp. as well as twenty-five from the encrusting gorgonian Solenopodium stecbei collected on the Great Barrier Reef off Australia have added significantly to this group of diterpenes (2,3). E. caribaeorum is an encrusting gorgonian that is not readily distinguished from Briareum asbartinum. Previous investigations of this organism have yielded erythrolidesA-I (2,4). Erythrolides A E11 and B E27 have not been reported thus far from any other organism and may well be chemotaxonomic markers for E. caribaeorum. We report here our investigation of E. caribaeorum collected off the coast of Tobago. In addition to compounds 1 and 2, we also isolated erythrolide E 131 (2) and a new diterpene which we have named erythrolide J {47. Erythrolides A 117, B 127, and E 137 were identified by comparison oftheir respective H-nmr spectral data with those reported in the literature (2,4). The complete 'H and 1 I5 0 1 1 '0 1 2 O b c I 0 3 0 4

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Four more alkaloids have been isolated from Lycopodium jawcettii. Lycoditle and des-Smethyl-a-obscurine have been found in other Lycopodiunz species but base L, CIaH31N04, apd base R, are new. Some transformations of base L are described including sts conversion to the previously described base 0. . An unstable base from L. clavatum has been characterized as the picrate C I S H~~S O~. C~H~N~O~. Further characterization of the two bases fawcettidine (base F) and fawcettimine (base A) is reported.Many alkaloids have been reported (1 (a,b)) from L. fawcettii; most of these possess the lycopodine (2) type of skeleton, although neither lycopodine itself nor any of its simple relatives (those with one or no oxygen functions) have been isolated. Three bases have more recently been isolated from this Jamaican plant, all of which contain two nitrogen atoms. Two of these (from the weaker bases), lycodine (3) and des-N-methyl-a-obscurine (4), have been previously isolated and are of known structure but the other, obtained from countercurrent distribution of the stronger base fraction, is not previously described.The latter, base R, C16Hz4N202, forms only a monoperchlorate (B. HC104) and from infrared spectra its structure includes carbonyl and secondary amino groups. Acetylation of base R affords a neutral oily compound showing N-acetyl absorption in the infrared.Another new strong base containing only one nitrogen atom has also been found. Base L, which analyzes best for C18H31N04, is shown from its infrared spectrum to contain an 0-acetyl residue and two hydroxyl groups. Since the methiodide prepared from base L is normal (B. MeI) the nitrogen is-presumably tertiary and this is confirmed by acetylation which gives the diacetate CzoHaaNOe, identical with base 0 described elsewhere (1 (b)). Further acetylation of base 0 is ineffective so the other hydroxyl grouping was thought to be tertiary and this suspicion is strengthened by the chromium trioxide oxidation of base L to the hydroxy-keto-acetate, Ci~H29N04. The latter is readily hydrolyzed to the dihydroxy-ketone (desacetyldehydro-base L), C~~H Z~N O~, which shows infrared absorption attributable to a six-membered (or larger) ring ketone. Neither hydroxyl in desacetyldehydro-base L is suitably placed relative to the ketone for ready elimination.Base L hydrolyzes to a trihydroxy compound, desacetyl-base L, C16H29N03, which consumes no periodic acid implying that it contains no cis a-glycol system. Acetylation of desacetyl-base L a t room temperature gives rise to the diacetate, base 0 , but a t low temperature (5") a monoacetate is obtained which is not base L and must be the positional isomer, isobase L (cf. fawcettimine (5) and lycofoline (6)), since on further acetylation it also affords base 0. These preliminary results suggest that base L is a tricyclic tertiary base possessing a tertiary hydroxyl, a secondary equatorial hydroxyl, and a secondary axial 0-acetyl grouping.

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Six tetranortriterpenoids including four new compounds, ruageanins A (3), B (4), C (5), and D (6), were isolated from fruits of Ruagea glabra (Meliaceae). Structures of the new compounds were established by analysis of the high-field NMR data. Methyl angolensate (1), xylocarpin (2), and ruageanins A (3) and B (4) showed significant antifeedant activity to the final instar larvae of Spodoptera frugiperda.

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