Effects of different cultivation conditions on the production of ß-cyclocitral and ß-ionone in Microcystis aeruginosa.

BACKGROUND: Cyanobacteria blooms have become a major environmental problem and concern because of secondary metabolites produced by cyanobacteria released into the water. Cyanobacteria produce volatile organic compounds (VOCs), such as the compounds ß-cyclocitral and ß-ionone, which comprise odors, off-flavors, defense compounds, as well as growth regulators. Therefore, the general objective of this work was to evaluate the VOCs produced by two strains of Microcystis aeruginosa, differing in their ability to produce microcystins (LTPNA 01-non-producing and LTPNA 08-toxin-producing). The analysis of VOC production was carried out in (1) normal culture conditions, (2) under different light intensities (LI), and (3) after the external application of ß-ionone in both cultures. RESULTS: The results showed that ß-cyclocitral and ß-ionone are produced in all growth phases of LTPNA 01 and LTPNA 08. Both strains were producers of ß-cyclocitral and ß-ionone in normal culture conditions. It was observed that the ß-cyclocitral concentration was higher than ß-ionone in all light intensities investigated in this study. Additionally, the strain LTPNA 01 produced more ß-cyclocitral than LTPNA 08 at almost all times and LIs analyzed. However, the strain LTPNA 08 produced more ß-ionone, mainly at the initial times. In addition, the experiment results with the external addition of ß-ionone in the cultures showed that the strain LTPNA 01 produced more ß-cyclocitral in control conditions than in treatment. Nonetheless, ß-ionone production was higher in treatment conditions in LTPNA 08, indicating that the addition of ß-ionone may favor the production of these compounds and inhibit the production of ß-cyclocitral. CONCLUSION: Our results showed that some abiotic factors, such as different light intensities and external application of ß-ionone, can be triggers that lead to the production of VOCs.

Effect of non-wine Saccharomyces yeasts and bottle aging on the release and generation of aromas in semi-synthetic Tempranillo wines.

Interest in the use of non-conventional yeasts in wine fermentation has been increased in the last years in the wine sector. The main objective of this manuscript was to explore the aromatic diversity produced by wild and non-wine strains of S. cerevisiae, S. eubayanus, S. kudriavzevii, and S. uvarum species in young and bottle-aged Tempranillo wines as well as evaluate their fermentation capacity and the yield on ethanol, glycerol, and organic acids, that can contribute to diminishing the effects of climate change on wines. S. uvarum strain U1 showed the highest ability to release or de novo produce monoterpenes, such as geraniol and citronellol, whose values were 1.5 and 3.5-fold higher than those of the wine S. cerevisiae strain. We found that compared to the normal values for red wines, ß-phenylethyl acetate was highly synthesized by U1 and E1 strains, achieving 1 mg/L. Additionally, after aging, wines of S. eubayanus strains contained the highest levels of this acetate. Malic acid was highly degraded by S. kudriavzevii yeasts, resulting in the highest yields of lactic acid (>5-fold) and ethyl lactate (>2.8-fold) in their wines. In aged wines, we observed that the modulating effects of yeast strain were very high in ß-ionone. S. uvarum strains U1 and BMV58 produced an important aging attribute, ethyl isobutyrate, which was highly enhanced during the aging. Also, the agave S. cerevisiae strain develops an essential aroma after aging, reaching the highest ethyl leucate contents. According to the results obtained, the use of wild non-wine strains of S. cerevisiae and strains of the cryotolerant species S. eubayanus, S. kudriavzevii, and S. uvarum in Tempranillo wine fermentation increase the aroma complexity. In addition, wines from S. kudriavzevii strains had twice additional glycerol, those from S. uvarum 4-fold more succinic acid, while wines from wild strains yielded 1% v/v less ethanol which may solve wine problems associated with climate change.

Meaningful Words in Crowd Noise: Searching for Volatiles Relevant to Carpenter Bees among the Diverse Scent Blends of Bee Flowers.

Olfactory cues constitute one of the most important plant-pollinator communication channels. Specific chemical components can be associated with specific pollinator functional groups due to pollinator-mediated selection on flower volatile (FV) emission. Here, we used multivariate analyses of FV data to detect an association between FVs and the worldwide distributed pollinator group of the carpenter bees (Xylocopa spp.). We compiled FVs of 29 plant species: 9 pollinated by carpenter bees, 20 pollinated by other bee pollinator functional groups. We tested whether FV emission differed between these groups. To rule out any phylogenetic bias in our dataset, we tested FV emission for phylogenetic signal. Finally, using field assays, we tested the attractive function of two FVs found to be associated with carpenter bees. We found no significant multivariate difference between the two plant groups FVs. However, seven FVs (five apocarotenoid terpenoids, one long-chain alkane and one benzenoid) were significantly associated with carpenter bee pollination, thus being "predictor" compounds of pollination by this pollinator functional group. From those, ß-ionone and (E)-methyl cinnamate presented the highest indicator values and had their behavioural function assessed in field assays. Phylogenetic signal for FVs emission was weak, suggesting that their emission could result from pollinator-mediated selection. In field assays, the apocarotenoid ß-ionone attracted carpenter bees, but also bees from other functional groups. The benzenoid (E)-methyl cinnamate did not attract significant numbers of pollinators. Thus, ß-ionone functions as a non-specific bee attractant, while apocarotenoid FVs emerge as consistent indicators of pollination by large food-foraging bees among bee-pollinated flowers.

Antimicrobial, antioxidant, volatile and phenolic profiles of cabbage-stalk and pineapple-crown flour revealed by GC-MS and UPLC-MSE.

Unconventional parts of vegetables represent a rich source of health-promoting phytochemicals. The phenolic profile of cabbage-stalk flour (CSF), pineapple-crown flour (PCF), and their essential oils were characterized via UPLC-ESI-QTOF-MSE and GC-FID/MS. Antimicrobial activity was tested against five strains, and antioxidant activities were determined in free and bound extracts. Globally, 177 phenolics were tentatively identified in PCF (major p-coumaric acid, ferulic acid, and 4-hydroxybenzaldehyde) and 56 in CSF (major chlorogenicacid, quercetin 3-O-glucuronide, and p-coumaric acid). PCF exhibited a distinguished profile (lignans, stilbenes) and antioxidant capacity, especially in bound extracts (1.3 g GAE.100 g-1; 0.6 g catechin eq.100 g-1; DPPH: 244.7; ABTS: 467.8; FRAP: 762.6 µg TE.g-1, ORAC: 40.9 mg TE.g-1). The main classes of volatile compounds were fatty acids, their esters, and terpenes in CSF (30) and PCF (41). A comprehensive metabolomic approach revealed CSF and PCF as a promising source of PC, showing great antioxidant and discrete antimicrobial activities.

Engineering Saccharomyces cerevisiae for the Overproduction of ß-Ionone and Its Precursor ß-Carotene.

ß-ionone is a commercially attractive industrial fragrance produced naturally from the cleavage of the pigment ß-carotene in plants. While the production of this ionone is typically performed using chemical synthesis, environmentally friendly and consumer-oriented biotechnological production is gaining increasing attention. A convenient cell factory to address this demand is the yeast Saccharomyces cerevisiae. However, current ß-ionone titers and yields are insufficient for commercial bioproduction. In this work, we optimized S. cerevisiae for the accumulation of high amounts of ß-carotene and its subsequent conversion to ß-ionone. For this task, we integrated systematically the heterologous carotenogenic genes (CrtE, CrtYB and CrtI) from Xanthophyllomyces dendrorhous using markerless genome editing CRISPR/Cas9 technology; and evaluated the transcriptional unit architecture (bidirectional or tandem), integration site, and impact of gene dosage, first on ß-carotene accumulation, and later, on ß-ionone production. A single-copy insertion of the carotenogenic genes in high expression loci of the wild-type yeast CEN.Pk2 strain yielded 4 mg/gDCW of total carotenoids, regardless of the transcriptional unit architecture employed. Subsequent fine-tuning of the carotenogenic gene expression enabled reaching 16 mg/gDCW of total carotenoids, which was further increased to 32 mg/gDCW by alleviating the known pathway bottleneck catalyzed by the hydroxymethylglutaryl-CoA reductase (HMGR1). The latter yield represents the highest total carotenoid concentration reported to date in S. cerevisiae for a constitutive expression system. For ß-ionone synthesis, single and multiple copies of the carotene cleavage dioxygenase 1 (CCD1) gene from Petunia hybrida (PhCCD1) fused with a membrane destination peptide were expressed in the highest ß-carotene-producing strains, reaching up to 33 mg/L of ß-ionone in the culture medium after 72-h cultivation in shake flasks. Finally, interrogation of a contextualized genome-scale metabolic model of the producer strains pointed to PhCCD1 unspecific cleavage activity as a potentially limiting factor reducing ß-ionone production. Overall, the results of this work constitute a step toward the industrial production of this ionone and, more broadly, they demonstrate that biotechnological production of apocarotenoids is technically feasible.

ß-ionone inhibits nonalcoholic fatty liver disease and its association with hepatocarcinogenesis in male Wistar rats.

Among the primary neoplasias that affect the liver, hepatocellular carcinoma (HCC) is the most frequent and the third leading cause of death related to cancer. Several risk factors predispose individuals to HCC such as nonalcoholic fatty liver disease (NAFLD), whose incidence has significantly increased worldwide. ß-ionone (ßI) isoprenoid is a known chemopreventive of hepatocarcinogenesis. However, the effects of this compound on NAFLD isolated or in association with hepatocarcinogenesis have not yet been evaluated. A high-fat emulsion administered for 6 weeks resulted in NAFLD in male rats, and oral treatment with ßI during this period significantly attenuated its development. Moreover, the presence of NAFLD potentiated hepatocarcinogenesis induced by the resistant hepatocyte (RH) model in these animals by increasing the number and percentage of the liver section area occupied by placental glutathione S-transferase (GST-P)-positive persistent preneoplastic lesions (pPNLs), that are thought to evolve into HCC. This indicates that this NAFLD/RH protocol is suitable for studies of the influence of NAFLD on the HCC development. Therefore, here we also investigated the chemopreventive effect of ßI under these two associated conditions. In this context, ßI reduced the number and percentage of the liver section area occupied by pPNLs, as well as cell proliferation and the number of oval cells, which are considered potential targets for the development of HCC. Thus, ßI presents not only a promising inhibitory effect on NAFLD isolated but also chemopreventive activity when it is associated with hepatocarcinogenesis.

Efeito quimiopreventivo da Beta-ionona na hepatocarcinogênese associada à fibrose hepática / Chemopreventive effect of Beta-ionone in hepatocarcinogenesis associated with hepatic fibrosis

O carcinoma hepatocelular (HCC) é a neoplasia primária mais frequente que acomete o fígado, a quarta principal causa de morte relacionada ao câncer e apresenta mau prognóstico. A fibrose hepática está presente em grande parte dos casos de HCC e é um dos principais fatores de risco para esta afecção. Segundo estudos prévios do grupo, a ß-ionona (BI), presente em uvas e aromatizantes de vinho, apresenta potencial quimiopreventivo na hepatocarcinogênese principalmente por reduzir o número e tamanho de lesão pré neoplásica (LPN) e inibir a proliferação celular. No entanto, até o presente não foram identificados na literatura estudos que investigaram o efeito deste isoprenóide no processo fibrótico e na hepatocarcinogênese a ele associada. Desta forma, este estudo pretendeu investigar o potencial efeito quimiopreventivo da BI na hepatocarcinogênese associada à fibrose hepática. Para tanto, ratos machos Wistar foram tratados com óleo de milho (OM) [0,25 ml / 100 g de peso corporal (p.c.); Grupo de OM] ou BI (16mg / 100g p.c.; Grupo BI) durante 18 semanas. A partir da 2ª semana, todos os animais receberam uma dose intraperitoneal de dietilnitrosamina (DEN - 50 mg / Kg p.c.) uma vez por semana até a 16ª semana. Os animais foram eutanasiados em diferentes períodos do protocolo experimental: na 10a semana (grupos OMP1 e BIP1), na 14a semana (grupos OMP2 e BIP2) e na 18ª semana (grupos OMP3 e BIP3). O isoprenóide demonstrou, de maneira inédita na literatura, inibir o desenvolvimento da fibrose hepática em diferentes estágios da hepatocarcinogênese (pontos 1, 2 e 3) por reduzir (p < 0,05) a porcentagem de área marcada para picrosirius. Além disso, BI reduziu a porcentagem de área positiva para α- SMA (p < 0,05) e as concentrações de hidroxiprolina (p < 0,05) no ponto 2. Foi observada ação quimiopreventiva da BI nas fases iniciais da hepatocarcinogênese (pontos 1 e 2) mesmo em modelo associada a fibrose por reduzir (p < 0,05) o número e porcentagem de área do corte ocupada por LPN GSTP positivas. Este efeito não foi observado em fase mais avançada da hepatocarcinogênese (ponto 3). Corroborando este dado não foram observadas diferenças em relação ao número de tumores (p>=0,05) avaliados por imageamento e por análise histopatológica. No entanto, quando comparados ao seu controle (OMP3), os animais do grupo BIP3 apresentaram menor mortalidade e menor incidência (p < 0,05) de HCC high, considerado um tipo mais agressivo de HCC, sugerindo que este composto possa atuar na agressividade das células tumorais. O grupo BIP2 demonstrou ainda menor proliferação celular (p < 0,05) quando comparado ao grupo OMP2. Assim foram avaliadas as vias de proliferação celular PI3K/AKT e MAPK/ERK, bem como as proteínas p21 e p53, relacionadas a progressão do ciclo celular. Não foram observadas(p≥0,05) alterações nestas vias por parte do isoprenóide. O presente estudo demonstrou ação protetora da BI no desenvolvimento de fibrose, bem como na hepatocarcinogênese a ela associada. Contudo, são necessárias análises complementares para elucidar mecanismos pelos quais a BI atua na carcinigênese hepática associada à fibrose

Hepatocellular carcinoma (HCC) is the primary liver cancer, the fourth leading cause of death related to cancer and presents a poor prognosis. Hepatic fibrosis is present in most cases of HCC and represents one of the main risk factors for this condition. According to previous studies of the group, ß-ionone (BI), present in grapes and wine flavorings, has a potential chemopreventive in hepatocarcinogenesis mainly by reducing the number and size of preneoplastic lesions (LPN) and inhibiting cell proliferation. However, to date, no studies have been identified in the literature that investigated the effect of this isoprenoid on the fibrotic process and in its association with hepatocarcinogenesis. Thus, this study aimed to investigate the potential chemopreventive effect of BI in hepatocarcinogenesis associated with hepatic fibrosis. Male Wistar rats were treated with corn oil (OM) [0.25 ml / 100 g body weight (b.w.); OM] or BI group (16mg / 100g b.w; BI group) for 18 weeks. From week 2, all animals received an intraperitoneal dose of diethylnitrosamine (DEN - 50 mg / kg b.w.) once in a week until week 16. The animals were euthanized at different periods of the experimental protocol: at week 10 (groups OMP1 and BIP1), at week 14 (groups OMP2 and BIP2) and week 18 (groups OMP3 and BIP3). The isoprenoid, for the first time in the literature, shown to inhibit the development of liver fibrosis at different stages of hepatocarcinogenesis (points 1, 2 and 3) by reducing (p <0.05) the percentage of the area labeled for picrosirius. Also, BI reduced the percentage of α-SMA positive area (p <0.05) and hydroxyproline concentrations (p <0.05) at point 2. BI chemopreventive action was observed in the early stages of hepatocarcinogenesis (point 1 and 2) even in a model associated with fibrosis for reducing (p <0.05) the number and percentage of the liver section area occupied by GSTP positive LPN. This effect was not observed at a later stage of hepatocarcinogenesis (point 3). Corroborating this data, no differences were observed regarding the number of tumors (p>=0.05) evaluated by imaging and histopathological analysis. However, when compared to its control (OMP3), animals from the BIP3 group had lower mortality and lower incidence (p<0.05) of HCC high, considered a more aggressive type of HCC, suggesting that this compound may act in aggressiveness of tumor cells. The BIP2 group also showed lower cell proliferation (p <0.05) when compared to the OMP2 group. Thus, PI3K / AKT and MAPK / ERK cell proliferation pathways were evaluated, as well as p21 and p53 proteins, related to cell cycle progression. No changes were observed in these pathways by the isoprenoid (p≥0.05). The present study demonstrated the protective action of BI in the development of fibrosis, as well as its association with hepatocarcinogenesis. However, further analysis is needed to elucidate mechanisms by which BI acts on fibrosis-associated liver carcinogenesis

Efeito quimiopreventivo da ß-ionona nas fases de iniciação e seleção/promoção da hepatocarcinogênese associada ao desenvolvimento de esteatose hepática não alcoólica em ratos Wistar / Chemopreventive effect of ß-ionone in the phases of initiation and selection/promotion of hepatocarcinogenesis associated with the development of non-alcoholic steatosis in Wistar rats

O câncer é um dos principais problemas de saúde pública no mundo. Dentre as neoplasias primárias que acometem o fígado, o carcinoma hepatocelular (HCC) é a mais frequente. Diversos fatores de risco predispõem ao HCC, entre eles a doença hepática gordurosa não-alcoólica (NAFLD). Segundo estudos prévios do grupo, a ß-ionona (BI), presente em uvas e aromatizantes de vinho, apresenta potencial quimiopreventivo da hepatocarcinogênese. Além disso, a ßI parece atuar na redução da colesterolemia podendo, assim, influenciar a NAFLD. Desta forma pretendeu-se, neste projeto, avaliar o desenvolvimento da NAFLD e sua influência nas etapas de iniciação e seleção/promoção da hepatocarcinogênese em ratos Wistar submetidos ao modelo do hepatócito resistente (RH), além da atividade quimiopreventiva da ßI, nessas condições experimentais em ratos. Para isso, os animais foram alocados em 6 grupos experimentais: RH iniciação (n=11), NAFLD iniciação (n=15), BI iniciação (n=15), RH seleção/promoção (n=11), NAFLD seleção promoção (n=15) e BI seleção/promoção (n=15). Na fase de iniciação os animais do grupo NAFLD receberam, diariamente, emulsão hipercalórica até a sexta semana do experimento um dia antes da administração de DEN. Já na fase de seleção/promoção os animais do grupo NAFLD receberam a emulsão hipercalórica, a partir de um dia após a DEN. Os animais dos grupos RH da iniciação e da seleção/promoção servem como controles e receberam, diariamente, 1mL/100g peso corpóreo de água até a sexta semana do experimento e um dia após a DEN, respectivamente. Na fase de iniciação, após 13 semanas os animais do grupo NAFLD não demonstraram sinais de esteatose, apresentaram maiores níveis séricos de triacilglicerol, colesterol total e LDL comparados ao grupo RH (P<0,05). O grupo NAFLD apresentou maior porcentagem de nódulos macroscópicos, bem como maior número e porcentagem de área hepática de lesões pré neoplásicas persistentes (pLPN) comparado ao grupo RH (P<0,05). Já o grupo BI apresentou menor número de pLPN e maior número de lesões em remodelação e uma maior porcentagem de área hepática de rLPN (p<0,05). Em relação a proliferação celular, o grupo NAFLD apresentou maior número de células em sourrounding, pLPN e rLPN comparada ao grupo RH e o grupo BI menor número em pLPN comparada a NAFLD. Já na fase de seleção/promoção foi possível observar o grupo NAFLD tem maiores valores de focos de inflamação, hepatócitos balonizados e grau de esteatose hepática em relação ao grupo BI, assim como maiores níveis séricos de triacilgliceróis, colesterol total e LDL (p<0,05). O grupo NAFLD apresentou maior porcentagem de nódulos macroscópicos <1, maior número, menor tamanho médio de pLPN comparados ao grupo RH (p<0,05). O grupo BI apresentou menor número e menor porcentagem de área em pLPN e maior porcentagem de área em rLPN (p<0,05). Em relação a proliferação celular, o grupo NAFLD apresentou maior número de células em sourrounding, pLPN e rLPN comparada ao grupo RH (p<0,05). Na expressão gênica, o grupo BI apresentou maior expressão de HMGCR em relação grupo NAFLD (p<0,05), O grupo NAFLD apresentou maior expressão de INSIG1 em relação ao grupo RH (p<0,05) e tendência na expressão de INSIG 2

Cancer is a major public health problems in the world. Among the primary neoplasm affecting the liver, hepatocellular carcinoma (HCC) is the most frequent. Several risk factors predispose to HCC, including the non-alcoholic fatty liver disease (NAFLD). According to previous studies of the group, ß-ionone (BI), present in grapes and flavors of wine, it presents potential chemopreventive of hepatocarcinogenesis. Furthermore, ßI appears to act in reducing blood cholesterol and may thus influence NAFLD. In this way it was intended in this project, evaluate the development of NAFLD and its influence on the steps of initiation and selection/promotion of hepatocarcinogenesis in Wistar rats resistant hepatocyte model (HR), and the chemopreventive activity of ßI, these experimental conditions in rats. For this, the animals were divided into 6 groups: RH initiation (n = 11), NAFLD initiation (n = 15), BI initiation (n = 15), HR selection / promotion (n = 11), NAFLD selection promotion ( n = 15) and BI selection / promotion (n = 15). In the inception phase of the NAFLD group animals received daily calorie emulsion until the sixth week of the experiment one day prior to DEN administration. In the selection / promotion stage NAFLD group of animals received hypercaloric emulsion, from one day after the DEN. The animals of groups HR and selection of initiation / promotion serve as controls and received daily 1mL / 100g body weight of water until the sixth week of the experiment, and one day after DEN respectively. In the initiation phase, after 13 weeks the animals of group NAFLD showed no signs steatosis, had higher serum levels of triglyceride, total cholesterol and LDL compared to the HR group (P <0.05). The NAFLD showed higher prevalence of macroscopic nodules as well as higher number and percentage of liver area of persistent pre-neoplastic lesions (pLPN) compared to the HR group (P <0.05). But the BI group had fewer pLPN and higher number of lesions in remodeling and a higher percentage of liver area rLPN (p <0.05). In relation to cell proliferation, the NAFLD group had a higher number of cells in sourrounding, pLPN and rLPN compared to the RH group and the lowest number in pLPN BI group compared to NAFLD. In the selection / promotion layer was observed NAFLD group has the highest values of inflammation foci, balonizados hepatocytes and hepatic steatosis grade in relation to BI group as well as higher serum levels of triglyceride, total cholesterol and LDL (p <0 , 05). The NAFLD showed higher prevalence of macroscopic nodules <1, more, smaller average size pLPN compared to the HR group (p <0.05). The BI group had fewer and smaller percentage area in pLPN and higher percentage of area rLPN (p <0.05). In relation to cell proliferation, the NAFLD group had a higher number of cells in sourrounding, pLPN and rLPN compared to the HR group (p <0.05). In gene expression, the BI group showed higher expression of HMGCR regarding NAFLD group (p <0.05), the NAFLD group had higher expression of INSIG1 against the RH group (p <0.05) and a tendency in the expression of INSIG 2

Chemical vs. biotechnological synthesis of C13-apocarotenoids: current methods, applications and perspectives.

Apocarotenoids are natural compounds derived from the oxidative cleavage of carotenoids. Particularly, C13-apocarotenoids are volatile compounds that contribute to the aromas of different flowers and fruits and are highly valued by the Flavor and Fragrance industry. So far, the chemical synthesis of these terpenoids has dominated the industry. Nonetheless, the increasing consumer demand for more natural and sustainable processes raises an interesting opportunity for bio-production alternatives. In this regard, enzymatic biocatalysis and metabolically engineered microorganisms emerge as attractive biotechnological options. The present review summarizes promising bioengineering approaches with regard to chemical production methods for the synthesis of two families of C13-apocarotenoids: ionones/dihydroionones and damascones/damascenone. We discuss each method and its applicability, with a thorough comparative analysis for ionones, focusing on the production process, regulatory aspects, and sustainability.

Calcium and potassium content in beef: influences on tenderness and associations with molecular markers in Nellore cattle.

Calcium (Ca) and potassium (K) are essential nutrients in animal nutrition. Furthermore, the Ca content can influence meat tenderness because it is needed by the proteolytic system of calpains and calpastatins, major factors in postmortem tenderization of skeletal muscles. K content, which is needed for muscle contraction, can also affect meat tenderness. This study showed that K positively affects the Warner-Bratzler shear force (WBSF), measured at 14days of meat aging, which means that higher levels of K are related to lower meat tenderness. Additionally, a significant effect (P≤0.015) of a SNP in the calcium-activated neutral protease 1 (CAPN1) gene on Ca content was observed. Metal content in beef can affect not only nutritional values but also meat quality traits. Part of this effect may be related to variation in specific genes.

The floral scent of Taccarum ulei (Araceae): attraction of scarab beetle pollinators to an unusual aliphatic acyloin.

The strongly fragrant thermogenic inflorescences of Taccarum ulei (Araceae) are highly attractive to night-active scarab beetles of Cyclocephala celata and C. cearae (Scarabaeidae, Cyclocephalini), which are effective pollinators of plants in the wild in northeastern Brazil. GC-MS analysis of headspace floral scent samples of T. ulei established that two constituents, (S)-2-hydroxy-5-methyl-3-hexanone (an aliphatic acyloin rarely detected in flowers) and dihydro-ß-ionone (an irregular terpene) accounted for over 96% of the total scent discharge. Behavioral tests (in both field and cages) showed that male and female C. celata and C. cearae were attracted to traps baited with a synthetic mixture of both compounds; however, they were also responsive to (S)-2-hydroxy-5-methyl-3-hexanone alone, which thus functions as a specific attractive cue. These findings support other recent research in suggesting that angiosperms pollinated by cyclocephaline scarab beetles release floral odors of limited complexity in terms of numbers of compounds, but often dominated by unusual compounds that may ensure attraction of specific pollinator species.

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm²) compared to control (0.91 ± 0.07 apoptotic cells/mm²). The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcrvpdate=20110329inogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.