The constituents of Carapa guianensis Aubl. and their biogenetic relationship

A/D-rings-seco limonoids from the fruits of Aglaia edulis and their bioactivities

Agledulines A-K, eleven previously undescribed limonoids, including eight biogenic A/D-rings-seco limonoid analogs (agledulines A-H), one D-ring-seco limonoid (agleduline I) and two A-ring-seco limonoids with a rare Δ^4,28 moiety (agledulines J-K), together with twelve reported limonoids, were isolated from the fruits of Aglaia edulis. Their structures were determined by NMR data, HRESIMS, X-ray diffraction, ECD spectra and the CD exciton chirality method. Observably, the absolute configurations of agleduline A, agleduline C and nymania 2 were unambiguously elucidated by single-crystal X-ray diffraction analyses. The biological evaluation showed that agleduline C exhibited significant cytotoxic activities with IC₅₀ values of 10.05 μM, and 11α-acetoxygedunin showed notable anti-inflammatory activity (IC₅₀: 4.70 μM). In addition, agleduline I and 11α-acetoxygedunin reversed the multidrug resistance with IC₅₀ values of 5.05 and 1.49 μM (RI: 4.64 and 15.77) in the MCF-7/Dox cells.

Characterization and Antifungal Activity of Limonoid Constituents Isolated from Meliaceae Plants Melia dubia, Aphanamixis polystachya, and Swietenia macrophylla against Plant Pathogenic Fungi In Vitro

The plants of Meliaceae are native to tropical and subtropical regions as the Americas, west India, Southeast Asia, and Southern China. Many species of the genera Khaya, Swietenia, Aphanamixis, and Melia in this family are known as medicinal plants and have biological activities such as antiviral, antimicrobial, antifeeding, insecticidal, and cytotoxic properties. The objectives of this research are to characterize and evaluate the bioactive limonoids from several plants of Meliaceae against phytopathogenic fungi. During the search of antifungal compounds from the plants of Meliaceae, the three methanol extracts of Melia dubia, Aphanamixis polystachya, and Swietenia macrophylla were found to suppress the mycelial growth of several phytopathogenic fungi. Nine limonoids isolated from M. dubia (1–2), A. polystachya (3–5), and S. macrophylla (6–9) were evaluated, for the first time, their antifungal effectiveness against nine phytopathogenic fungi Fusarium oxysporum, Magnaporthe oryzae, Sclerotium rolfsii, Rhizoctonia solani, Alternaria spp., and Botrytis cinerea, and three oomycetes Phytophthora species. Limonoids 2, 3, 6, and 8 displayed a remarkable broad-spectrum antifungal activity against all the test fungi. Sclerotium rolfsii was highly sensitive to the four limonoids with IC50 values ranging from 79.4 to 128.0 µg/mL. Notably, chisocheton compound G (3) isolated from A. polystachya and khayanolide B (8) isolated from S. macrophylla were the most potent antifungal limonoids and exhibited a dose-dependent activity against Phytophthora species. Compounds 2 and 9 displayed moderate activity against M. oryzae. Our study results demonstrated the discovery of antifungal and lead compounds from the group of limonoids for application in the control of fungal plant diseases.

Development of a biocompatible magnetic nanofluid by incorporating SPIONs in Amazonian oils

Higher quality magnetic nanoparticles are needed for use as magnetic nanoprobe in medical imaging techniques and cancer therapy. Moreover, the phytochemistry benefits of some Amazonian essential oils have sparked great interest for medical treatments. In this work, a magnetic nanoprobe was developed, allying the biocompatibility and superparamagnetism of iron oxide nanoparticles (SPIONs) with benefits associated with Amazonian oils from Copaiba and Andiroba trees. SPIONs were obtained by two thermal decomposition procedures and different amounts of precursors (iron acetylacetonates). Their characterization was accomplished by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy and magnetization. The obtained nanoparticles composition and magnetic properties were not affected by the relative proportion of iron(II) and iron(III) in the precursor system. However, when changing the reducing and stabilizing agents the coating layer shows different compositions/relative weight - the more promising SPIONs have a coating mainly composed by oleylamine and an iron oxide:coating wt% ratio of 55:45. Nanoparticles size distributions were very narrow and centred in the average size of 6-7nm. Cellular assays confirmed the biocompatibility of SPIONs and their effective internalization in human colon cancer cells. Mössbauer/XRD results indicated maghemite as their main iron oxide phase, but traces of magnetite proved to be present. Magnetization saturations of 57emu/g at 5K and 42emu/g at 300K were achieved. With incorporation of SPIONs into Copaiba and Andiroba essential oils, these values show a 4-fold decrease, but the supermagnetic behaviour is preserved providing the effective formation of a nanofluid.

In vitro and in vivo anti-malarial activity of limonoids isolated from the residual seed biomass from Carapa guianensis (andiroba) oil production

BACKGROUND

Carapa guianensis is a cultivable tree used by traditional health practitioners in the Amazon region to treat several diseases and particularly symptoms related to malaria. Abundant residual pressed seed material (RPSM) results as a by-product of carapa or andiroba oil production. The objective of this study was to evaluate the in vitro and in vivo anti-malarial activity and cytotoxicity of limonoids isolated from C. guaianensis RPSM.

METHODS

6α-acetoxyepoxyazadiradione (1), andirobin (2), 6α-acetoxygedunin (3) and 7-deacetoxy-7-oxogedunin (4) (all isolated from RPSM using extraction and chromatography techniques) and 6α-hydroxy-deacetylgedunin (5) (prepared from 3) were evaluated using the micro test on the multi-drug-resistant Plasmodium falciparum K1 strain. The efficacy of limonoids 3 and 4 was then evaluated orally and subcutaneously in BALB/c mice infected with chloroquine-sensitive Plasmodium berghei NK65 strain in the 4-day suppressive test.

RESULTS

In vitro, limonoids 1-5 exhibited median inhibition concentrations (IC50) of 20.7-5.0 μM, respectively. In general, these limonoids were not toxic to normal cells (MRC-5 human fibroblasts). In vivo, 3 was more active than 4. At oral doses of 50 and 100 mg/kg/day, 3 suppressed parasitaemia versus untreated controls by 40 and 66%, respectively, evidencing a clear dose-response.

CONCLUSION

6α-acetoxygedunin is an abundant natural product present in C. guianensis residual seed materials that exhibits significant in vivo anti-malarial properties.

Viability of Cabralea canjerana extracts to control the South American fruit fly, Anastrepha fraterculus

Several representatives of Meliaceae contain biologically active compounds that are toxic to insects with few negative effects on the environment and humans. Our study evaluated the activity of ethyl acetate and ethanol extracts from the fruit and seeds of Cabralea canjerana (Vellozo) Mart (Sapindales: Meliaceae) on Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae). Limonoids and triterpenes were detected in fruit and seed extracts. Each extract was added to an artificial diet at three concentrations and tested after 24, 48, and 72 hr of extract application. Ethyl acetate extracts were the most active ones and showed the effect of both dose and time elapses after application on the insects. The highest toxic effect on A. fraterculus adults was from ethyl acetate extracts from fruit, followed by extracts from seeds. These extracts showed antifeedant activities. Extract solutions sprinkled on fruits of Carica papaya (L.) (Brassicales: Caricaceae) caused oviposition repellency and negatively affected the biological development of A. fraterculus. Ethyl acetate extracts highly hampered oviposition, but seed extracts showed lesser oviposition deterrence. The fruit and seed extracts diminished pupal viability. Particularly, the ethyl acetate fruit extract caused malformed adults. The sex ratio was also affected, resulting in female predominance for the fruit extract, while the seed extract showed a dose-dependent effect. Low doses caused male abundance, but at higher concentrations the effect was reversed. These encouraging results showed that the C. canjerana extracts have great potential as new tools to be used in integrated pest management programs to protect fruits against A. fraterculus.

Antimicrobial activity of Amazonian oils against Paenibacillus species

The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB.

6α-Acetoxy-gedunin

THE TITLE COMPOUND [SYSTEMATIC NAME: (1S,3aS,4aR,4bS,5S,6R,6aR,10aR,10bR,12aS)-5,6-bis-(acet-yloxy)-1-(3-fur-yl)-1,5,6,6a,7,10a,10b,11,12,12a-deca-hydro-4b,7,7,10a,12a-penta-methyl-oxireno[c]phenanthro[1,2-d]pyran-3,8(3aH,4bH)-dione], C(30)H(36)O(9), is a limonoid-type triterpene isolated from Aglaia elaeagnoidea (A. Juss.) Benth. (Meliaceae) from Queensland, northern Australia. It contains the gedunin core of four trans-fused six-membered rings with an oxirane ring annelated to the fourth ring. A terminal 3-furyl unity and two acet-oxy groups in a mutual cis-disposition supplement the mol-ecule. A comparison between the gedunin cores of the title compound, the parent compound gedunin, and three further gedunin derivatives revealed considerable variations in their conformation stemming from the conformational lability of the first screw-boat ring and the third twist-boat ring. A sensitive measure for the third ring is one C-C-C-C torsion angle, which is 14.2 (2)° in the title compound, but varies in other cases from ca 20 to ca -40°. In the crystalline state, 6α-acetoxy-gedunin shows ten comparatively weak C-H⋯O inter-actions, with H⋯O distances in the range of 2.33-2.69 Å.

A toxicological evaluation of the effect of Carapa guianensis Aublet on pregnancy in Wistar rats

The effects of the administration of Carapa guianensis Aublet (Meliaceae) seed oil were investigated during pregnancy in female Wistar rats. Five groups of pregnant rats (n=5-9 per group) were treated orally from the 7th to the 14th day of pregnancy (organogenic period), at doses of: 0, 0.375, 0.75, 1.5 and 3.0gkg(-1). On the 20th day of pregnancy, the animals were sacrificed and laparotomized to evaluate reproductive parameters. The results showed that there was no difference between the control and treated groups in terms of the number of live and dead fetuses, the dam-offspring relationship, the weight of the fetus, the weight of the placentae and ovaries, the number of implantation sites, the number of resorption sites, the number of corpora lutea in the ovaries, and the pre- and post-implantation loss rates. It is therefore concluded that administration of Carapa guianensis seed oil did not bring about any toxic effect on pregnancy in Wistar rats.