Amides have been recognized as potent insecticidal natural products but, despite their variety of targets and mechanisms of action, their metabolic fate in insects is virtually unknown. The currently accepted hypothesis is that specialist herbivores are capable of biotransforming xenobiotics rendering them more polar and excretable while generalist insects do not have comparable capacity. The leaves from Piper tuberculatum, rich in insecticide amides, were offered to two insect species found on Piper leaves under natural conditions and also to four generalist grasshoppers in order to compare their capacity of biotransforming xenobiotics. The amides 1-7 were identified in the P. tuberculatum leaves and their corresponding carboxylic acids 8-13 were detected in frass samples of two host insects suggesting that these species promote the amides hydrolysis. The four generalist grasshoppers when offered P. tuberculatum leaves, starved to death after 72 h, indicating a strong antifeedant activity of P. tuberculatum leaves.

The known kavalactones (E)-4-methoxy-6-styryl-2H-pyran-2-one, 4-methoxy-6-(3-phenyloxiran-2-yl)-2H-pyran-2-one, 6-(1,2-dihydroxy-2-phenylethyl)-4-methoxy-2H-pyran-2-one, the three benzoic acid derivatives methyl-4-methoxy-3-(3'-methyl-2'-butenyl)benzoate and methyl 2,2-dimethyl-4-oxochroman-6-carboxylate, and a new methyl 4-methoxy-3-(3-methylbut-2-enoyl)benzoate were isolated from the ethanolic extract of Piper fuligineum. The structures of these compounds were determined by using a combination of spectroscopic methods, including 1D- and 2D-nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. This is the first report of the chemical study of P. fuligineum, and the methyl 4-methoxy-3-(3-methylbut-2-enoyl)benzoate is described as a new natural product.

Piper gaudichaudianum Kunth (Piperaceae) accumulates gaudichaudianic acid, a prenylated benzopyran, as its major component. Interestingly, this trypanocidal compound occurs as a racemic mixture. Herein, transcriptomic investigations of Piper gaudichaudianum using the RNA-seq approach are reported, and from the analysis of the transcripts expressed it was possible to propose a complete biosynthetic pathway for the production of gaudichaudianic acid, including the steps that originate its precursor, p-hydroxybenzoic acid. Peperomia obtusifolia (L.) A. Dietr. (Piperaceae) also accumulates racemic benzopyrans, however, its chromanes originate from the polyketide pathway, while the chromenes from Piper derives from the shikimate pathway. Recent transcriptomic and proteomic studies of the former species did not identify polyketide synthases involved in the production of the benzopyran moiety, but revealed the expression of tocopherol cyclase, which may be responsible for the cyclization of the 3,4-dihydro-2H-pyran ring. The analysis of the enzymes involved in the secondary metabolism of Piper gaudichaudianum and the comparison with the data previously obtained from Peperomia obtusifolia can provide valuable information on how these compounds are biosynthesized.

Bemisia tabaci (Hemiptera: Aleyrodidae) biótipo B é uma das mais limitantes pragas do tomateiro no mundo. A produção do tomateiro é altamente dependente de inseticidas, ocasionando problemas ao produtor, consumidor e ambiente. Uma alternativa promissora para redução dos efeitos maléficos ocasionados pelo uso indiscriminado de inseticidas sintéticos são os inseticidas de origem botânica. Este trabalho objetivou avaliar o efeito de extratos aquosos a 3% (p/v) de diferentes estruturas de treze espécies botânicas no comportamento dos insetos adultos de B. tabaci biótipo B bem como sua atividade inseticida sobre ovos, ninfas e adultos do inseto em tomate. A água destilada foi utilizada como controle negativo e o inseticida tiametoxam (18 g/100 L de água) como controle positivo. O extrato à base de folhas de Toona ciliata foi o mais eficiente nos testes em que foram avaliados o efeito dos extratos sobre o comportamento da mosca-branca, diminuindo o número de insetos adultos e ovos em folíolos de tomateiro. O extrato de folhas de Piper aduncum apresentou o maior efeito ovicida (78,00% de ninfas não eclodidas), no entanto foi pouco efetivo sobre ninfas e adultos. Os extratos de folhas de Trichilia pallida, Trichilia casaretti e Toona ciliata apresentaram os maiores índices de controle (67,9; 60,3; 55,1%, respectivamente). Para adultos, T. pallida foi o mais eficiente (72,8%). Com base nos resultados, a aplicação dos extratos de T. pallida, T. ciliata e T. casaretti mostra-se promissora no manejo de infestações de B. tabaci biótipo B em tomateiro.

Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B is one of the most limiting pests of tomato crops in the world. Tomato yield is currently dependent on the use of pesticides, which are problematic to farmers, consumers and the environment. A promising alternative to reduce the harmful effects caused by the indiscriminated use of synthetic insecticides is the use of insecticides of botanical origin. This study aimed to evaluate the effect of 3% (w/v) aqueous extracts from different structures of thirteen botanical species on the behavior of B. tabaci biotype B adults, as well as insecticidal activity of such aqueous extracts on B. tabaci eggs, nymphs, and adults infesting tomato plants. A distilled water solution was used as a negative control, and thiamethoxam insecticide (18 g/100 L of water) as a positive control. Leaf extract of Toona ciliata was observed to have the most efficient inhibitory effect in tests of extracts on whitefly behavior. Furthermore, the use of leaf extract of Toona ciliata led to the most drastic reduction in the number of adults and eggs on tomato leaflets. Leaf extract of Piper aduncum led to the greatest observed ovicidal effect (78.00% of non-hatched nymphs); however it was not effective against nymphs and adults. The leaf extracts of Trichilia pallida, Trichilia casaretti, and Toona ciliata showed the highest control indexes (67.9, 60.3, and 55.1%, respectively). For adults mortality, T. pallida was the most effective (72.8%). Our results indicate that application of extracts of T. pallida, T. ciliata, and T. casaretti are promising strategies to manage B. tabaci biotype B on tomato.

En el Nuevo Mundo el género iPiper (Piperaceae) comprende al menos 500 especies en las que muchos compuestos biológicamente activos fueron identificados; es por ello que el estudio sobre la química y biosíntesis de los miembros de este género son de gran interés, donde el cultivo de tejidos in vitro juega un rol fundamental. El propósito de este trabajo fue desarrollar varios sistemas de cultivo in vitro, en diferentes especies de Piper, con la finalidad de propagarlas clonalmente y regenerarlas por organogénesis directa para el establecimiento de plantas en campo, y la conservación y transferencia internacional de germoplasma. La germinación de semillas alcanzó aproximadamente entre el 20 y el 99% después de 4 semanas de cultivo. La micropropagación fue realizada en medio de cultivo MS suplementado con sacarosa 3%, AIA 0,02 mg L-1 y AG3 0,02 mg L-1. El potencial morfogenético de explantes de raíz, peciolo, hoja, nudo y entrenudo fue investigado con la finalidad de desarrollar un protocolo confiable de regeneración de plantas. La conservación e intercambio internacional de germoplasma in vitro también fue realizado, entre Perú, Brasil y Ecuador.

In the New World the genus Piper (Piperaceae) contains at least 500 species in which many biologically active compounds were identified; is why the study of the chemistry and biosynthesis in members of this genus are of interest, and here techniques in vitro tissue culture plays a fundamental role. The aim of this work was to establish several in vitro culture systems in different Piper species in order to propagate clonally and regenerate by direct organogenesis for the establishment the field plants, the conservation and international germoplasm exchange. The seed germination achieved approximately 20 - 99% after 4 weeks of culture. The micropropagation was performed on MS culture medium supplemented with sucrose (3%), IAA (0,02 mg L-1) and GA3 (0,02 mg L-1). Callus induction and morphogenetic potential of root, petiole, leaf, node and internode explants was investigated to develop a reliable plant regeneration protocol. The in vitro germplasm conservation and international germplasm exchange also was realized, between Perú, Brazil and Ecuador.

Se evaluó la actividad larvicida del "matico" neotropical Piper tuberculatum. Los compuestos secundarios fueron extraídos de hojas, tallos y espigas maduras (con frutos y semillas) de plantas silvestres y de plantas in vitro de P. tuberculatum. Fue evaluada la toxicidad aguda de extractos de espigas maduras con frutos y semillas y de plantas in vitro de P. tuberculatum sobre el "cogollero" Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) mediante bioen-sayos de contacto. Solamente extractos Diclorometano:metanol (CH2Cl2:MeOH) (2:1) y etanólicos (EtOH) de espigas maduras y el extracto CH2Cl2:MeOH (2:1) de plantas in vitro mostraron niveles significativos de mortalidad. Los extractos CH2Cl2:MeOH (2:1) y EtOH de espigas maduras causaron 90% de mortalidad cuando dosis de 0,1850 mg/µL se aplicaron sobre S. frugiperda en 24 y 48 h de exposición, respectivamente. El extracto CH2Cl2:MeOH (2:1) de plantas in vitro causó 95% de mortalidad cuando dosis de 0,1850 mg/µL también se aplicaron en 48 h de exposición. Los mejores resultados para las espigas maduras fueron: CL50 0,001 mg/µL con EtOH y 0,007 mg/µL con CH2Cl2:MeOH (2:1) y CL90 0,027 mg/µL con EtOH y 0,103 mg/µL con CH2Cl2:MeOH (2:1); y en el caso de las plantas in vitro, solamente el extracto CH2Cl2:MeOH (2:1) fue: CL50 0,003 mg/µL y CL90 0,060 mg/µL. Se discute el valor potencial de los extractos de P. tuberculatum como un eficiente insecticida sobre S. frugiperda.

The larvicidal activity of the neotropical "matico" Piper tuberculatum was evaluated. The secondary compounds were extracted of leaves, stems and mature spikes with fruits and seeds from wild plants and in vitro plants of Piper tuberculatum. The acute toxicities to the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), of extracts of spikes with fruits and seeds and in vitro plants of P. tuberculatum were evaluated by means of contact bioassays. Only CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes and CH2Cl2:MeOH (2:1) extract from in vitro plants showed significant levels of larval mortality. The CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes caused 90% mortality when doses of 0.1850 mg/µL were applied to the S. frugiperda in 24 and 48 h of exposure, respectively. The CH2Cl2:MeOH (2:1) extract from in vitro plants caused 95% mortality when doses of 0.1850 mg/mg/µL were too applied in 48 h of exposure. The mature spikes test best results were: LD50 0.001 mg/µL with EtOH and 0.007 mg/mg/µL with CH2Cl2:MeOH (2:1) and LD90 0.027 mg/µL with EtOH and 0.103 mg/µL with CH2Cl2MeOH (2:1); and, in the case of in vitro plants, only CH2Cl2:MeOH (2:1) extract was: LD50 0.003 mg/µL and LD90 0.060 mg/µL. The potential value of extracts derived from P. tuberculatum as efficient insecticides against S. frugiperda is discussed.

Dengue is a tropical disease caused by an arbovirus transmitted by Aedes aegypti. Since no effective vaccine is available for treating dengue, the present study focused on population vector control through investigating the use of the lignan grandisin, isolated from Piper solmsianum C. DC., Piperaceae, against the larvae of A. aegypti. Grandisin caused larval (L3) mortality at LC50 150 µg/mL. Histological analysis on A. aegypti larvae treated with grandisin (LC50 50 µg/mL) showed changes in the anterior-middle midgut, with intense tissue destruction and cell disorganization.

Um novo meroterpeno, 4-[(2'E)-3',7'-dimetilocta-2',6'-dienil]-5-metil-2-(3''-metilbut-2"‑enil)-benzeno-1,3-diol, além de oito substâncias conhecidas, foi isolado do extrato em MeOH das folhas de Peperomia oreophila Hesch. O fenol prenilado foi também isolado como principal componente do extrato em CH2Cl2:MeOH das folhas de Peperomia arifolia Miq. As estruturas das substâncias foram estabelecidas com base em dados espectrais e comparação com dados descritos na literatura

One new meroterpene, 4-[(2'E)-3',7'-dimethylocta-2',6'-dien-1'-yl]-5-methyl-2-(3"‑methylbut-2"-enyl)-benzene-1,3-diol, together with eight known compounds, was isolated from the MeOH extract from the leaves of Peperomia oreophila Hesch. The prenylated phenol was also isolated as main compound from the CH2Cl2:MeOH extract from leaves of Peperomia arifolia Miq. The structures of the substances were established on the basis of the spectral evidences and supported by literature data.

O perfil metabólito baseado na aplicação de análises multivariadas (análise de componentes principais, PCA) dos dados de espectrometria de massas com ionização electrospray (ESIMS) no modo positivo e de ressonância magnética nuclear (RMN) do ¹H de extratos brutos de espécies de Piper destacou algumas espécies caracterizadas pela produção de lignanas (P. solmsianum, P. truncatum e P. cernuum), neolignanas (P. regnellii) e cromenos (P. gaudichaudianum). Análises específicas em conjunto de espécies caracterizadas morfologicamente por apresentarem inflorescências pêndulas e globosas (P. caldense, P. carniconnectivum, P. bowiei e P. permucronatum) ou em espécies que produzem amidas indicaram o potencial mais significativo para tais análises como critério para estudos fitoquímicos posteriores. Análises intraespecíficas de plântulas das espécies P. solmsianum, P. regnellii e P. gaudichaudianum indicaram uma composição química nas folhas baseada na presença dos fenilpropanóides dilapiol e apiol, diferentemente do que produzem as plantas adultas. No caso das espécies que produzem amidas, a composição apresentou-se relativamente constante independentemente do estágio de desenvolvimento.

The metabolomic profiling based on the application of multivariate analysis (principal component analysis, PCA) of positive mode electrospray ionization mass spectrometric (ESIMS) and ¹H nuclear magnetic resonance (NMR) data of crude extracts highlighted some species characterized by lignans (P. solmsianum, P. truncatum and P. cernuum), neolignans (P. regnellii) and chromenes (P. gaudichaudianum). A specific analysis focusing on species having pendant and globular inflorescences (P. caldense, P. carniconnectivum, P. bowiei and P. permucronatum) or amides-producing species indicated higher potential of the methodology in determining similarities and establishing priorities for further phytochemical investigation. Such intraspecific analysis applied to analyzed seedling leaves of the P. solmsianum, P. regnellii and P. gaudichaudianum species revealed the production of dillapiole and apiole instead of lignans, neolignans or prenylated benzoic acid, produced by the adult leaves, respectively. In case of amides-producing species, a similar profile was observed regardless the developmental stage.

Extrato de folhas de Piper scutifolium apresentou atividade antifúngica significativa contra Cladosporium cladosporioides e C. sphaerospermum e seus principais componentes ativos, piperina, piperlonguminina e corcovadina foram isolados por meio de purificação biomonitorada, apresentando limites de detecção de 1 µg. Foi realizado um estudo da relação estrutura-atividade baseado na síntese de doze análogos com variações no número de insaturações, no padrão de substituição no anel aromático e no grupo amídico. As amidas sem substituintes no anel aromático e com apenas uma ligação dupla foram as mais ativas e os derivados N,N-dietil-substituídos apresentam maior dose-dependência.

The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 µg. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity.

Piper tuberculatum Jacq. (Piperaceae) is used in traditional Peruvian medicine as anti-inflammatory and disinfectant of wounds in humans and domestic animals. This species contains amides bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. The aim of this work was to investigate antifungal activity of crude extracts from the spikes, leaves and stems of wild plants extracted with CH2Cl2:MeOH (2:1), EtOH, decoction, and in vitro plants extracted with CH2Cl2:MeOH (2:1). The crude extracts showed antifungal activity on Trichophyton rubrum, Mycosporum canis y M. gypseum. The minimum inhibitory concentration (MIC) observed with CH2Cl2:MeOH (2:1), EtOH and decoctions extracts against T. rubrum, M. canis and M. gypseum was 0,1 mg/mL for spikes and leaves, and 0,1 to 0,5 mg/mL for stems. The inhibition of growth using in vitro plants on T. rubrum and M. canis was 100% in 0,5 mg/mL, and 95% on M. gypseum 95% using 1,5 mg/mL of concentration.

En la medicina tradicional Peruana Piper tuberculatum Jacq. (Piperaceae) es utilizado en humanos y animales domésticos como antiinflamatorio y desinfectante de heridas. Piper tuberculatum contiene las amidas isobutílicas, pirrolidina, dihidropiridona y piperidina. El objetivo de este trabajo fue investigar la actividad antifúngica de los extractos crudos de inflorescencias, hojas y tallos de plantas silvestres, obtenidos con CH2Cl2:MeOH (2:1), EtOH y decocción y de plantas in vitro obtenido con CH2Cl2:MeOH (2:1). Los extractos crudos exhibieron actividad antifúngica sobre Trichophyton rubrum, Microsporum canis y M. gypseum. La concentración inhibitoria mínima (CIM) observada con los extractos CH2Cl2:MeOH (2:1), EtOH y decocción, sobre Trichophyton rubrum, Microsporum canis y M. gypseum fue 0,1 mg/mL para inflorescencias y hojas, y 0,1 a 0,5 mg/mL para tallos. En plantas in vitro la inhibición en el crecimiento de T. rubrum y M. canis fue 100% en 0,5 mg/mL y para M. gypseum fue 95% en 1,5 mg/mL de concentración.

Foram isoladas de extratos de folhas de Ocotea catharinensis Mez (Lauraceae) quatorze neolignanas sendo nove benzofurânicas (incluindo três novas substâncias 1e, 2f e 4b), uma secobenzofurânica inédita (3b), duas biciclo[3.2.1]octânicas (incluindo a nova 5c), dois novos dímeros biciclo[3.2.1]octânicos (7a e 7b) e ainda dois sesquiterpenos (incluindo o novo humulanol 9). Nos embriões somáticos de O. catharinensis foram identificadas sete neolignanas incluindo uma nova neolignana biciclo[3.2.1]octânica (4a).

The extracts from leaves of Ocotea catharinensis Mez (Lauraceae) were found to contain fourteen neolignans and two sesquiterpenes: nine benzofuran types (including three new compounds 1e, 2f and 4b), one new seco-benzofuran type (3b), two bicyclo[3.2.1]octane types (including the new compound 5c), two new dimers of bicyclo[3.2.1]octane type (7a and 7b) and two sesquiterpenes (including a new humulanol 9). In addition, seven neolignans were also showed to occur in somatic embryos of O. catharinensis including one new bicyclo[3.2.1]octane type (4a).

The phytochemical investigation of Piper umbellata leaves yielded nine compounds including one terpenoid glucoside, five flavones (vitexin 2"-O-β-glucopyranoside, apigenin 8-C-β-D-glucopyranoside,orientin 8-C-β-D-glucopyranoside,5-hydroxy-7,3',4'-trimethoxy-flavone and velutin), two lignans (sesamin e dihydrocubebin) and 4-nerolidylcathecol. Excepting 4-nerolidylcathecol, all compounds have not been described from this species yet.

A biotransformação da lignana tetraidrofurânica, (-)-grandisina, pelo fungo endofítico Phomopsis sp, obtido de Viguiera arenaria, conduziu à formação de um novo metabólito caracterizado como 3,4-dimetil-2-(4'-hidróxi-3',5'-dimetóxifenil)-5-metóxi-tetraidrofurano. O metabólito foi analisado contra o parasita Trypanosoma cruzi, o agente causador da doença de Chagas, e mostrou uma atividade tripanocida (IC50 9,8 μmol L-1) similar ao precursor natural (IC50 3,7 μmol L-1).

The biotrasformation of the tetrahydrofuran lignan, (-)-grandisin, by the endophitic fungus Phomopsis sp, obtained from Viguiera arenaria, led to the formation of a new compound determined as 3,4-dimethyl-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-5-methoxy-tetrahydrofuran. The metabolite was evaluated against the parasite Trypanosoma cruzi, the causative agent of Chagas's disease, and showed a trypanocidal activity (IC50 9.8 μmol L-1) similar to the natural precursor (IC50 3.7 μmol L-1).