7-Hydroxycassine: A new 2,6-dialkylpiperidin-3-ol alkaloid and other constituents isolated from flowers and fruits of Senna spectabilis

alcaloides, também foram isolados constituintes químicos de outras classes como o esteroide β-sitosterol, os flavonoides luteolina e 3-metóxi-luteolina, o triterpeno ácido betulínico e o ácido trans-cinâmico. A partir do levantamento bibliográfico foi possível observar que os compostos estão sendo relatados pela primeira vez nesta espécie. The phytochemical study of flowers and green fruits of Senna spectabilis furnished a new substituted 2,6-dialkylpiperidin-3-ol alkaloid, named (-)-7-hydroxycassine, along with five known piperidine alkaloids: (-)-cassine, (-)-spectaline, (-)-3-O-acetylspectaline, (-)-7-hydroxyspectaline and (-)-iso-6-spectaline. In addition to non-alkaloidal, chemical constituents from other chemical classes were also identified, including the steroid β-sitosterol, the flavonoids luteolin and 3-methoxyluteolin, the triterpene betulinic acid and trans-cinnamic acid. To our knowledge, compounds are being reported for the first time in this species. Keywords: Senna spectabilis, (-)-7-hydroxycassine, piperidine alkaloids Introduction Senna and Cassia are considered the two most representative genera of the Fabaceae family, with some species used in folk medicine. The placement of these genera in the family has always been controversial, and in the new classification of Fabaceae, several species of Cassia were included in the genus Senna due to being morphologically similar. 1 These species are known to biosynthesize flavonoids, anthraquinones, stilbenes and alkaloids. Many of these substances have been described for their biological and pharmacological properties, which include antibacterial, laxative, anti-ulcerogenic, cytotoxic, antifungal, analgesic, antiinflammatory, antioxidant and hepatoprotective qualities. 6 as sources of piperidine alkaloids of long chain 2,6-dialkylpiperidin-3-ol, which are rare in nature. 8 Senna spectabilis is a tree used in urbanization and occurs from Minas Gerais to Rio Grande do Sul States. 9,10 The species is used in folk medicine for the treatment of constipation, insomnia, anxiety, epilepsy, malaria, (-)-7-Hydroxycassine: a New 2,6-Dialkylpiperidin-3-ol Alkaloid and other Constituents 14 demonstrated that the alkaloidic extract obtained from the bark of this plant acts on central nervous system. 14 In another study, Sriphong et al. 13 isolated several alkaloids from flowers of S. spectabilis, among them, a new 3(R)-benzoyloxy-2(R)-methyl-6(R)-(11'-oxododecyl)-piperidine, and reported toxic and cytotoxicity activities of the metabolites. For more than two decades, researchers at the Nucleus for Bioassays, Biosynthesis and Ecophysiology of Natural Products (NuBBE, UNESP, Araraquara-SP, Brazil) have been investigating S. spectabilis from a chemical and biological standpoint, and this has resulted in the isolation of several bioactive alkaloids of the type 2,6-dialkylpiperidin-3-ol. 6, Chemical studies of the flowers and fruits of S. spectabilis led to the isolation of a new alkaloid 2,6-dialkylpiperidin-3-ol (1), as well as another five metabolites from distinct chemical classes, which, although well known, are being reported for the first time in this plant. Experimental Instrumentation and chromatographic material The uni-and bi-dimensional experiments of C) using tetramethylsilane (TMS) as internal standard. The absorption spectra in the region of infrared (FTIR) were recorded on a FTIR spectrometer (Nicolet-Impact 400 coupled to a microcomputer provided with Omnic 1.20 software) using KBr pellets for solids and films for oily substances. The high resolution mass spectra with electrospray ionization (HRESIMS) were measured on an ultrOTOF Q (Bruker Daltonics) spectrometer, operating in the positive mode and using MeOH/H 2 O (4:1) as solvent system. Melting points were determined on a digital device, made by the Microquímica products, model number MQAPF-301 and are uncorrected. Optical rotations were measured on a Perkin Elmer model 341 polarimeter equipped with a sodium lamp (λ = 589 nm) at 20 °C using CH 2 Cl 2 as a solvent. In chromatographic separations, trademarks Acros silica gel (70-230 mesh) and Sigma neutral alumina (70-290 mesh) were used for gravitational chromatography, and for pressurized separations, Silica gel (230-400 mesh) was used. For separations using chromatography for molecular exclusion, Sephadex LH-20 was used. The comparative thin layer chromatography (TLC) was performed with 60 silica gel (Ø 5-40 µm, Merck) and neutral alumina gel (Ø 5-40 µm, Aldrich) with fluorescence indicator in the range of 254 nm (F 254 Extraction and isolation The flowers and buds (3.4 kg) of S. spectabilis were dried, powdered and macerated in EtOH for seven days, resulting in 39.7 g of crude extract (EB-FL). EB-FL was redissolved in MeOH/H 2 O (4:1) and partitioned with n-hexane, AcOEt, CH 2 Cl 2 and n-BuOH, resulting in n-hexane (EFL-Hex, 2.0 g), ethyl acetate (EFL-Ac, 0.34 g), dichloromethane (EFL-Dic, 7.9 g) and n-butanol (EFL-But, 2.5 g) fractions. Analysis by TLC, using iodochloroplatinate and Dragendorf revealed that EFL-Dic contained a greater diversity of alkaloid constituents. Following acid-base extraction, a mixture of alkaloids was obtained and subjected to fractionation by gravitational column chromatography on neutral alumina, eluted with a CHCl 3 /EtOH/n-hexane mixture through gradient elution, supplying 151 mg of (-)-3-O-acetylspectaline, a 4.82 g Viegas Junior et al. 3 Vol. 24, No. 2, 2013 mixture of (-)-cassine and (-)-spectaline and 270 mg of a more polar mixture containing three other alkaloids. This mixture was subjected to preparative TLC on alumina gel, eluted with CHCl 3 /EtOH/n-hexane, leading to the isolation of 5.5 mg of (-)-7-hydroxyspectaline, 20 mg of (-)-iso-6-spectaline, and 11 mg of (-)-7-hydroxycassine (1) obtained as a yellow-coloured oil. The chromatographic treatment of EFL-Hex resulted in the isolation of β-sitosterol (2). 19,21 The EFL-Ac fraction initially subjected to acid-base extraction, resulted in 240 mg of a non-alkaloidal fraction whose fractionation in a Sephadex ® LH-20 column, eluted with MeOH, provided 12 sub-fractions of 25 mL each. A preliminary analysis with 1 H NMR led to the selection of the sub-fraction 6, which following purification in a chromatographic column on silica gel resulted in a yellow solid, which decomposed above 320 °C, 22 identified as luteolin (3). 23 The green fruits (3 kg) of S. spectabilis were powdered and macerated in EtOH for five days, providing 13.1 g of crude extract (EB-FR). EB-FR was reconstituted in MeOH/H 2 O (4:1) and partitioned with n-hexano, CH 2 Cl 2 , AcOEt and n-BuOH, generating four fractions: EFR-Hex (0.29 g), EFR-Dic (0.87 g) EFR-Ac (1.15 g) and EFR-Bu (1.96 g), respectively. A preliminary analysis by TLC and 1 H NMR, led to the selection of fractions EFR-Dic and EFR-Bu for chemical study. The chromatographic treatment EFR-Dic, resulted in 150 sub-fractions of 10 mL each, regrouped into 13 new subfractions. The sub-fraction 42-44 (504 mg) was subjected to TLC, providing 20 mg of betulinic acid (5) 24 The sub-fraction 51-58 (248 mg) was subjected to column chromatographic (CC) on silica gel, eluted under reduced pressure with binary mixtures of EtOAc/Hex and EtOAc/ MeOH, providing 78 sub-fractions of 10 mL each, grouped according to similarity into 17 new sub-fractions. The subfraction 1-10 (42 mg) was purified by preparative HPLC, resulting in four new sub-fractions. The sub-fractions with retention times (t R ) of 23.2 and 27.6 min were analysed by 1 H and 13 C 1D and 2D NMR and compared with literature data, 21 leading to the identification of luteolin (3) (7.7 mg, t R = 23.2 min) of 3-methoxyluteolin (4) (8.4 mg, t R = 27.6 min). The fractionation of EFR-Bu in a reverse phase column C-18, eluted in gradient of H 2 O/MeOH, resulted in 8 sub-fractions of 500 mL each. The chromatographic fractionation of sub-fraction 4 (886 mg) in molecular exclusion column Sephadex ® LH-20, eluted with MeOH, resulted in the isolation of a white solid, melting range of 130-133 °C, was identified as trans-cinnamic acid (6)

Antioxidant properties of plant extracts: an EPR and DFT comparative study of the reaction with DPPH, TEMPOL and spin trap DMPO

This work presents a comparative study of the antioxidant activity of extracts from nine plant species belonging to the Brazilian flora - Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum - acting on the free-radicals DPPH (2,2-diphenyl-1-pierylhydrazyl) and TEMPOL (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy-1-oxyl) by electron paramagnetic resonance (EPR), and acting on the hydroxyl radical (OH circle) by the spin-trapping technique generated by a Fenton reaction. Results showed that the extracts of Iryanthera juruensis and Chrysophyllum inornatum display the strongest antioxidant activities. The results of scavenging tests were clarified by computational calculations - density functional theory (DFT), local density approximation (LDA) with SIESTA code - indicating that the energy released in the reduction reaction of TEMPOL is less than DPPH. Due to its availability and cost DPPH is more often used in these tests than TEMPOL, however TEMPOL should be considered when studying processes dealing with smaller energies

Aromatic compounds from three brazilian lauraceae species

Phytochemical investigations on three Brazilian Lauraceae species from, the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia

Saponinas antifúngicas de Swartzia langsdorffii

Chromatographic fractionation of the EtOH extract from the leaves of Swartzia langsdorffii afforded the pentacyclic triterpenes oleanolic acid and lupeol, and two saponins: oleanolic acid 3-sophoroside and the new ester 3-O-b-D-(6'-methyl)-glucopyranosyl-28-O-b-D-glucopyranosyl-oleanate. Their structures were elucidated from spectral data, including 2D NMR and HRESIMS experiments. Antifungal activity of all isolated compounds was evaluated, using phytopathogens Cladosporium cladosporioides and C. sphaerospermum, and human pathogens Candida albicans, C. krusei, C. parapsilosis and Cryptococcus neoformans

Antifungal Activity of Decyl Gallate against Several Species of Pathogenic Fungi

This work aims to demonstrate that the gallic acid structure modification to the decyl gallate (G14) compound contributed to increase the antifungal activity against several species of pathogenic fungi, mainly, Candida spp., Cryptococcus spp., Paracoccidioides spp., and Histoplasma capsulatum, according to standardized microdilution method described by Clinical Laboratory Standard Institute (CLSI) documents. Moreover this compound has a particularly good selectivity index value, which makes it an excellent candidate for broad-spectrum antifungal prototype and encourages the continuation of subsequent studies for the discovery of its mechanism of action

Flavonolignoids Iryanthera grandis

Este trabalho estabelece uma comparação entre amêndoas de Iryanthera Grandis Ducke (Myristicaceae) atacadas por insetos e amêndoas inteiras através do isolamento, identificação e determinação estrutural de alguns de seus constituintes químicos. Os extratos hexânicos foram fracionados por técnicas cromatográficas e forneceram a neolignana (8R,7\'S,8\'S)-2,3-dimetil-4-(p-hidroxifenil)-6-hidroxitetralina e a lactona (2S,3S,4S)-2-(heptadecil-17\'-fenil)-3-hidroxi-4-metilbutanolido, além de dois tocotrienóis: 2,8-dimetil-2-(4,8,12-trimetil-3,7,11-tridecatrienil)-6-cromanol e 2,8-dimetil-2-(4,12-dimetil-8-carbóxi-3,7,11-tridecatrienil)-6-cromanol, sendo o primeiro encontrado apenas nas amêndoas atacadas por insetos e o segundo, apenas nas amêndoas inteiras. Estas 4 substâncias já haviam sido isoladas de I. grandis em trabalho anterior. Um estudo quantitativo revelou a presença de 25% em massa a mais de metabólitos especiais nas amêndoas atacadas por insetos, quando comparadas às amêndoas inteiras, (provavelmente devido a uma maior concentração de triglicerídeos nas amêndoas inteiras). A investigação fitoquímica dos extratos etanólicos forneceu, após partição com solventes e fracionamentos cromatográficos, incluindo o uso de cromatografia líquida de alta eficiência, 4 flavonolignóides inéditos designados de iryantherinas G, H, I e J. A biossíntese de flavonolignóides envolve provavelmente o ataque eletrofilico de álcool cinamílico ao anel floroglucinólico de uma diidrochalcona. No caso destas iryantherinas, o álcool cinamílico é representado pela unidade 1,4-diaril-2,3-dimetilbutílica. As propostas estruturais das substâncias isoladas foram baseadas no exame de espectros dos produtos naturais e/ou dos derivados acetilados. As técnicas espectrométricas utilizadas foram EM, RMN de 1H e de 13C, RMN bidimensional HOMOCOSY 1H-1H, experimentos de DEPT 135° e para a observação do Efeito Nuclear Overhauser.This work describes the comparison between unspoiled fruits of Iryanthera Grandis (Ducke) and fruits which had been attacked by insects by means of isolation, identification and structural elucidation of some of its chemical constituents. Hexanic extracts submitted to chromatographic techniques afforded neolignan (8R,7\'S,8\'S)-2,3-dimethyl-4-(p-hydroxyphenil)-6-hydroxytetraline and lactone (2S,3S,4R)-2-(heptadecyl-17\'-phenyl)-3-hydroxy-4-methyl\'butanolide, besides two tocotrienols: 2,8-dimethyl-2-(4,8,12-trimethyl-3,7,11-tridecatrienyl)-6-cromanol and 2,8-dimethyl-2-(4,12-dimethyl-8-carboxyl-3,7,11-tridecatrienyl)-6-cromanol. Ethanolic extracts submitted to partition and chromatografic analysis including HPLC techmques afforded 4 new flavonolignoids, iryantherins G, H, I and J. Biosynthesis of flavonolignoids results from eletrophyllic attack of cinnamyl alcohol to the phloroglucinolic ring of a dihydrochalcone. In this work, the cinnamyl alcohol is represented by the 1,4-diaryl-2,3-dimethyl unit. Structural proposals of isolated compounds were based on MS, 1H and 13C NMR, bidimensional HOMOCOSY 1H-1H, DEPT 135° and NOE experiments

Chemical constituents Iryanthera sagotiana and Iryanthera lancifolia

O presente trabalho descreve o isolamento, identificação e determinação estrutural dos constituintes químicos das inflorescências e folhas de Iryanthera sagotiana e das inflorescências e pericarpos de I. lancifolia, espécies da família Myristicaceae, que ocorrem na Amazônia. A investigação fitoquímica das inflorescências de I. sagotiana (Benth.) Warb. forneceu, após extração, partição com solventes orgânicos e fracionamentos cromatográficos, quatro diidrochalconas: 2\',4\'-diidroxi-4,6\'- dimetoxidiidrochalcona (I) ; 2\',4\',6\'-triidróxi-4-metoxidiidrochalcona; 2\',4,4\'-triidróxi-6\'-metoxidiidrochalcona (II) e 2\',4\'-diidroxi-4-metóxi-6\'-glicopiranosil-diidrochalcona, sendo as duas últimas, inéditas. Foram também isolados e identificados o benzaldeído, o ácido diidro-p-cumárico, dois flavonóis glicosilados: afzelina e quercitrina e quatro flavanonóis glicosilados: engeletina, isoengeletina, astilbina e isoastilbina. Das folhas de I. sagotiana foram isoladas as diidrochalconas I, II e o dímero 3\',3\"\'-bis-2\', 4\',6\'-triidróxi-4-metoxidiidrochalcona, inédito na literatura, além da afzelina, quercitrina, engeletina e astilbina. Os pericarpos de I. lancifolia Ducke forneceram, após procedimentos cromatográficos, as diidrochalconas I e 2\',4-diidróxi-4\',6\'dimetoxidiidrochalcona, inédita, e três flavonolignóides também inéditos: rel (1\"R,2\"R,3\"S)-3\'-(1\",4\"-di-p-hidroxifenil-2\",3\"-dimetilbutil)-2\',4\'-diidróxi-4,6\'-dimetoxidiidrochalcona (III); rel (1\"R,2\"S,3\"R)-3\'-(1\",4\"-di-p-hidroxifenil-2\",3\"-dimetilbutil)-2\',4\'-diidróxi-4,6\'-dimetoxidiidrochalcona (IV) e 5\'-(1\",4\"-di-p-hidroxifenil-2\",3\"-dimetilbutil)-2\',6\'-diidróxi-4,4\'dimetoxidiidrochalcona. Foram isoladas também três lactonas policetídicas inéditas: (2S,3S,4S)-2-(7-dodecenil)-3-hidróxi-4-metil-butanolido, rel (2S,3R,4S)-2-(7\'-dodecenil)-3-hidróxi-4-metil-butanolido e 2-dodecil-3-hidróxi-4-metil-but-2-enolido, além do tocotrienol 2,8-dimetil-2-(4,8,12-trimetil-3,7,11-tridecatrienil)-6-cromanol e da lignana (8R,TS,8\'S)-4,4\'diidróxi-2,7\'-ciclolignana. Das inflorescências de I. lancifolia foram isolados a diidrochalcona I, os flavonolignóides III e IV, o tocotrienol e o esteróide 3-β-O-β-D-galactopiranosilsitosterol. A elucidação estrutural das substâncias isoladas foi baseada em métodos espectrométricos: EM, RMN de 1H e 13C (PND e DEPT 135°), técnicas de RMN bidimensionais (HOMOCOSY e HETERO-COSY) e experimentos para a observação de NOE. Reações de acetilação e epoxidação foram efetuadas para se obterem derivados mais informativos. As atividades antioxidantes da afzelina, da quercitrina, do flavonolignóide IV e do tocotrienol foram avaliadas em comparação com a atividade antioxidante da vitamina E, empregando-se a inibição da autooxidação de homogenato de cérebro como modelo experimental. A capacidade antioxidante foi medida pela produção de malonildialdeído (MDA) e a concentração necessária para inibir 50% da autoxidação (Ql/2) foi calculada. Os valores de Ql/2 obtidos para afzelina, quercitrina, flavonolignóide, tocotrienol e vitamina E foram, respectivamente: 62,30; 2,29; 4,83; 1,08 e 11,20 µM. Estes ensaios foram realizados pela pesquisadora Dra. Solange C. Davino e pela professora Dra. Sílvia B. M. Barros, da Faculdade de Ciências FarmacêutIcas da USP.This work describes the isolation, identification and structural elucidation of chemical constituents from inflorescences and leaves of Iryanthera sagotiana (Myristicaceae) and from inflorescences and pericarps of I. lancifolia, collected in Amazon region. After extraction and partition with organic solvents and chromatographic fractionation, phytochemical analysis of inflorescences of I. sagotiana (Benth.) Warb. afforded four dihydrochalcones: 2\',4\'-dihydroxy-4,6\'dimethoxydihydrochalcone (I); 2\',4\',6\'-trihydroxy-4-methoxy-dihydrochalcone; and the new 2\',4,4\'-trihydroxy-6\'-methoxy-dihydrochalcone (II) and 2\',4\'-dihydroxy- 4-methoxy-6\'-glucopyranosyl-dihydrochalcone. Benzaldehyde, dihydro-p-cumaric acid besides two glycosylated flavonols: afzelin and quercitrin and four glycosylated flavanonols: engeletin, isoengeletin, astilbin and isoastilbin were also isolated and identified. Leaves of I. sagotiana yielded dihydrochalcones I, II and the new dimer 3\',3\"\'-bis-2\',4\',6\'-trihydroxy-4-methoxydihydrochalcone in addition to afzelin, quercitrin, engeletin and astilbin. Pericarps of I. lancifolia Ducke afforded, after fractionation procedures, dihydrochalcones I e 2\',4-dihydroxy-4\',6\'-dimethoxy-dihydrochalcone, which has not been reported in literature yet, as well as three new flavonolignoids: rel (1\"R,2\"R,3\"S)-3\'-(1\",4\"-di-p-hydroxyphenyl-2\",3\"dimethylbutyl)-2\',4\'-dihydroxy-4,6\'-dimethoxydihydrochalcone (III); rel (1\"R,2\"S,3\"R)-3\'-(1\",4\"-di-p-hydroxyphenyl-2\",3\"-dimethylbutyl)-2\',4\'-dihydroxy-4,6\'-dimethoxydihydrochalcone (IV) e 5\'-(1\",4\"-di-p-hydroxyphenyl-2\",3\"dimethylbutyl)-2\',6\'-dihydroxy-4,4\'-dimethoxy-dihydrochalcone. Three new polyketide lactones were also isolated: (2S,3S,4S)-2-(7-dodecenyl)-3-hydroxy-4-methyl-butanolide, rel (2S,3R,4S)-2-(7\'-dodecenyl)-3-hydroxy-4-methylbutanolide e 2-dodecyl-3-hydroxy-4-methyl-but-2-enolide, besides tocotrienol 2,8-dimethyl-2-(4,8,12-trimethyl-3,7,11-tridecatrienyl)-6-cromanol and lignan (8R,T\'S,8\'S)-4,4\'-dihydroxy-2, 7\'-cyclo1ignan. From inflorescences of I. lancifolia, dihydrochalcone I, flavonolignoids III e IV, tocotrienol and the steroid 3-β-O-β-D-galactopyranosylsitosterol were isolated. Structural elucidation of the isolated compounds were based on spectrometric methods: MS, 1H and 13C NMR (PND and DEPT 135°), bidimensional NMR techniques (HOMOCOSY e HETERO-COSY) as well as NOE experiments. Acetylation and epoxidation reactions were carried out in order to get more informative derivatives. Antioxidant activities of afzelin, quercitrin, flavonolignoid IV and tocotrienol were evaluated in comparison with the antioxidant activity of vitamin E, using the inhibition of autoxidation of brain homogenates as a experimental model. The antioxidant capacity was measured by malondialdehyde (MDA) production and the necessary concentration to inhibit 50% of autoxidation (Q12) was calculated. The following values of Q1/2 were obtained for afzelin, quercitrin, flavonolignoid, tocotrienol and vitamin E, respectively: 62,30; 2,29; 4,83; 1,08 e 11,20 µM