Edson Rodrigues Fo

Norlimonoids from seeds of Toona ciliata

Abstract Further examination of the seeds of Toona ciliata led to the isolation of two new norlimonoids which were identified on the basis of spectroscopic analysis as 5α,6β,8α-trihydroxy-28-norisotoonafolin and 5α,6β,8α,12α-tetrahydroxy-28-norisotoonafolin. In addition, the known limonoids cedrelone and toonacilin and the sterols sitosterol, stigmasterol, campesterol and 3β-O-β- d -glucopyranosylsitosterol were also isolated and characterised. These results show that Toona has a less pronounced relationship to the Swietenioideae.

Limonoids from leaves of Khaya senegalensis

Abstract The leaves of Khaya senegalensis yielded two new limonoids. These compounds were identified on the basis of spectroscopic analysis as methyl 1α-acetoxy-3β,6,8α-trihydroxy-2α-methoxy-2β,14β-epoxy-[4.2.1 10,30 .1 1,4 ]-tricyclomeliac-7-oate and methyl 1α-acetoxy-6,8α,14β,30β-tetrahydroxy-3-oxo [3.3.1 10,2 .1 1,4 ]-tricyclomeliac-7-oate. Scopoletin, β-quercitrin and rutin were also isolated.

Sesquiterpenes, triterpenoids, limonoids and flavonoids of Cedrela odorata graft and speculations on the induced resistance against Hypsipyla grandella

Abstract From the stem of Cedrela odorata grafted on Toona ciliata var. australis were isolated calamenene, cycloeucalenol, sitosterol, stigmasterol, campesterol, gedunin, 7-deacetylgedunin, 7-deacetoxy-7-oxogedunin, methylangolensate, febrifugin, azadiradione, 20,21,22,23-tetrahydro-23-oxoazadirone, 3β-deacetylfissinolide and, catechin, together with the new limonoid 1α-methoxy-1,2-dihydrogedunin and the new cycloartane 3β-O-β- d - glucopyranosylcycloeucalenol . The limonoids were of little value to clarify the basis of the induced resistance in the graft against Hypsipyla grandella. The cycloartanes and catechin could have been translocated from Toona stock to the Cedrela graft.

Rearranged limonoids from Khaya senegalensis

Abstract The stems of Khaya senegalensis yielded three limonoids which appear to be novel. These compounds were identified on the basis of spectroscopic analysis as methyl 1α,6,8α,14β,30β-pentahydroxy-3-oxo-[3.3.1 10,2 .1 1,4 ]-tricyclomeliac-7-oate; methyl 1α,2β,3α,6,8α,14β-hexahydroxy-[4.2.1 10,30 .1 1,4 ]-tricyclomeliac-7-oate and methyl 1α-acetoxy-2β,3α,6,8α,14β-pentahydroxy-[4.2.1 10,30 .1 1,4 ]-tricyclomeliac-7-oate. The two latter ones represent a novel group of methyl tricyclomeliac-7-oates. Scopoletin, scoparon, sitosterol, stigmasterol, Campesterol and 3β-O-β- d -glucopyranosylsitosterol were also isolated.

Androstane and pregnane 2β,19-hemiketal steroids from Trichilia claussenii

Abstract The methanol extract of stems of Trichilia claussenii yielded three new steroids: 2α,3α-dihydroxyandrostan-16-one 2β,19-hemiketal, 2α,3β-dihydroxypregnan-16-one 2β,19-hemiketal, 2β,3β-dihydroxypregnan-16-one. Two known steroids 2β,3β,4β-trihydroxypregnan-16-one, 2α,3α,4β-trihydroxypregnan-16-one and a mixture of sitosterol and stigmasterol β- O - d -glucopyranosides were also isolated. The structures of the isolated compounds were determined on the basis of spectroscopic analysis.

A pyrano chalcone and a flavanone from Neoraputia magnifica

Abstract The hexane extract from the stems of N. magnifica var. magnifica , afforded two new flavonoids: 2′-hydroxy-3,4,4′,5-tetramethoxy-5′,6′-(2″,2″-dimethylpyran)chalcone and 5,6,7,3′,4′,5′-hexamethoxyflavanone which were identified on the basis of spectroscopic methods. The known flavonoids 2′-hydroxy-3,4,4′,5,6′-pentamethoxychalcone, 5,7,3′,4′,5′-pentamethoxyflavanone and 5,6,7,3′,4′,5′-hexamethoxyflavone, the sterols sitosterol and stigmasterol were also identified. These results do not seem to support the affiliation of Neoraputia to the tribe Cusparieae.

Canthin-6-one alkaloids from Picrolemma granatensis

Abstract From the branches of Picrolemma granatensis, besides scopoletin, the known canthin-6-one alkaloids 9-methoxycanthin-6-one, 9-hydroxycanthin-6-one, 4,5-dimethoxycanthin-6-one and the two new 8-hydroxy-9-methoxycanthin-6-one and 9-methoxycanthin-6_one 3-N-oxide were identified by full spectral analysis. The placement of a substituent at C-9 was established by NOE experiments.

Quassinoids and tetranortriterpenoids from Picrolemm granatensis

Abstract From the stem bark of Picrolemma granatensis were isolated two novel tetranortriterpenoids: 7α,21-dihydroxy-3-oxo-24,25,26,27-tetranorapotirucall-14,20(22)-dien-21,23-olide and 7α,21-dihydroxy-3-oxo-24,25,26,27-tetranorapotirucall-1,14,20(22)-trien-21,23-olide which were identified on the basis of spectroscopic and chemical methods. The triterpene melianodiol, the quassinoids simalikalactone-D, 2′- epi -simalikalactone-D and ailanthione, the sterols sitosterol, stigmasterol and campesterol were also identified.

New Spirorotenoids from Tephrosia candida

The ethyl acetate extract of roots of Tephrosia candida afforded three new spirorotenoids belonging to a new class of spirocompounds, named tephrospirolactone, tephrospiroketone I, and tephrospiroketone II. The structures of these compounds were determined mainly based on spectral analysis. The only known spirorotenoid described in the literature is amorphispironone, isolated from Amorpha fruticosa.

Anthrone and oxanthrone C,O-diglycosides from Picramnia teapensis.

Two C,O-diglycosylated compounds, the anthrone picramnioside F, and the oxanthrone mayoside C, were isolated from the stem bark of Picramnia teapensis, along with the previously reported anthraquinones, 1-O-beta-D- and 8-O-beta-D-glucopyranosyl emodin. The compounds were separated by recycling-HPLC, and their structures were determined on the basis of spectroscopic analysis. CD measurements were used to establish the absolute configuration of the anthrone and oxanthrone. The antifungal activity of 1-O-beta-D- and 8-O-beta-D-glucopyranosyl emodin against Leucoagaricus gongilophorus was shown to be similar to that of the lignan sesamin.