Two chromones from Peperomia vulcanica

Two chromones: 5-hydroxy-2-(14′-(E)-nonadecenyl) chromone (1) and 5-hydroxy-2-[12′-(3″,4″-methylenedioxyphenyl)dodecanyl] chromone (2), together with six known compounds have been isolated from Peperomia vulcanica Baker & C. H. Wright (Piperaceae). Their structures were determined by spectroscopic analysis including 2D NMR techniques.     

Unusual chromenes from Peperomia blanda

From the methanol extract of the aerial parts of Peperomia blanda (Piperaceae), two chromenes were isolated and characterized mainly through application of 2D-NMR spectroscopy. The structures were 2S-(4-methyl-3-pentenyl)-6-formyl-8-hydroxy-2,7-dimethyl-2H-chromene and 2S-(4-methyl-3-pentenyl)-5-hydroxy-6-formyl-2,7-dimethyl-2H-chromene named as blandachromenes I and II, respectively.     

Chemical and cytotoxic constituents from Peperomia sui

Three polyketide compounds, surinone A, surinone B, surinone C and one acylresorcinol, suranone, along with thirty known compounds, were isolated from the whole plant of Peperomia sui. Their structures were elucidated from spectral analysis. Several compounds showed cytotoxic activity against HONE-1 and NUGC-3 cell lines in vitro.     

Chromenes from Peperomia serpens (Sw.) Loudon (Piperaceae)

Chromatographic separation of the CH2Cl2 extract from leaves of Peperomia serpens yielded two chromenes [5-hydroxy-8-(3',7'-dimethylocta-2',6'-dienyl)-2,2,7-trimethyl-2H-1-chromene (1) and 5-hydroxy-8-(3'-methyl-2'-butenyl)-2,2,7-trimethyl-2H-1-chromene-6-carboxylic acid (2)], besides the known chromene [methyl 5-hydroxy-2,2,7-trimethyl-2H-1-chromene-6-carboxylate (3)] and the flavonoid, dihydrooroxylin (4). Their structural elucidation were achieved by spectroscopic analyses. The antifungal activities of the CH2Cl2 extract and the isolated chromenes were measured bioautographically against Cladosporium cladosporioides and C. sphaerospermum, when it was found that the crude extract showed higher activity as compared to the pure compounds.     

Trypanocidal tetrahydrofuran lignans from Peperomia blanda

Five tetrahydrofuran lignans and two known flavones were isolated from the aerial parts of Peperomia blanda. The structures of the isolated lignans were elucidated by interpretation of their spectroscopic data, including by gHMQC and gHMBC. The relative and absolute configurations of the isolates were determined from NOESY interactions and optical properties, respectively. Four of the lignans were diastereomeric whilst one was of mixed biosynthetic origin. All but one of the lignans exhibited high in vitro trypanocidal activity when assayed against epimastigotes of Trypanosoma cruzi strain Y.     

Chromenes of polyketide origin from Peperomia villipetiola

An extract of leaves and stems of Peperomia villipetiola has been found to contain myristicin (3-methoxy-4,5-methylenedioxy-allylbenzene) and seven chromenes, whose structures are methyl 5-hydroxy-7-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (1), methyl 5-methoxy-7-methyl-2,2-dimethyl-2H-1-chromene-8-carboxylate (2), methyl 7-hydroxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (3), methyl 7-methoxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (4), 5-methanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (5), 5-methanol-7-methoxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (6), and methyl 5-acetoxymethanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate (7). A biosynthetic rationale for 1-7 suggests that orsellinic acid may be a common intermediate. The anti-fungal activities of the chromenes were measured bioautographically against Cladosporium cladosporioides and Cladosporium sphaerospermum: compounds 6 and 7 were found to be the most active.     

Secolignans with antiangiogenic activities from Peperomia dindygulensis

Two new secolignans, peperomins G and H ( 1 and 2 , resp.), were isolated from the whole plant of Peperomia dindygulensis, together with five known secolignans, peperomin A ( 3 ), peperomin E ( 4 ), peperomin B ( 5 ), 2,3‐trans‐2‐methyl‐3‐{(3‐hydroxy‐4,5‐dimethoxyphenyl)[5‐methoxy‐3,4‐(methylenedioxy)phenyl]methyl}butyrolactone ( 6 ), 2,3‐cis‐2‐(hydroxymethyl)‐3‐{bis[5‐methoxy‐3,4‐(methylenedioxy)phenyl]methyl}butyrolactone ( 7 ). Their structures and configurations were elucidated by spectroscopic methods including 2D‐NMR techniques. Antiangiogenic effects of all compounds were evaluated using human umbilical vein endothelial cells (HUVEC) proliferation and tube‐formation tests, with compounds 4 and 5 being active in the bioassay. Compounds 4 and 5 induced obvious cell toxicity to HUVEC with IC₅₀ values of 1.64±0.19 and 8.44±0.4 μM , respectively. Compounds 4 and 5 also exhibited significant HUVEC tube formation‐inhibiting activity with IC₅₀ values of 3.13±0.09 and 6.24±0.12 μM , respectively.     

Rearranged limonoids and chromones from Harrisonia perforata and their anti-inflammatory activity

Two new rearranged limonoids, harperforatin (1) and harperfolide (2), and a new chromone, harperamone (3), were isolated from fruits and roots of Harrisonia perforata, together with eight known compounds. Their structures were elucidated on the basis of spectroscopic data. Harperfolide (2) exhibited potent anti-inflammatory activity by suppressing nitric oxide (NO) production from activated macrophages with IC₅₀ value of 6.51 μM. Furthermore, its effect is mediated by reduction of iNOS protein expression, attributable to the inhibitory action of LPS-induced NO production.     

Phenology and pollination biology of eight Peperomia species (Piperaceae) in semideciduous forests in southeastern Brazil

Data on flowering phenology and pollination of Peperomia species are virtually non-existent. This study presents data on the pollination biology of eight Peperomia species from south-eastern Brazil, including the flowering phenology, pollination system, and reproductive success. Data on flowering phenology were recorded weekly and exclusion experiments on inflorescences provided data on autonomous self- and wind pollination. Direct visual observations were made and insect visits were recorded. Four Peperomia species showed continuous flowering, while the others were seasonal and flowered in the wet season. Pollination by wind and Syrphidae was confirmed for two self-incompatible Peperomia species. The remaining species are self-compatible and their high fruit set may be accounted for by autonomous self-pollination and perhaps agamospermy. Although the floral morphology of Peperomia species suggests wind- and/or insect pollination, most of the species studied exhibit autogamy and perhaps agamospermy as the main method of reproduction.     

Two amides from Piper amalago

The hexane extracts of the roots of Piper amalago afforded two trans-cinnamoylamides, 2-methoxy-4,5-methylenedioxy-trans-cinnamoyl piperidide and pyrrolidide.     

草胡椒属植物的化学成分和药理活性研究进展

综述了到目前为止发表的有关草胡椒属的化学成分,主要为木脂素类和色原酮类,对该属的药理活性也作了简要的概括。     

Phylogeny of the genus Peperomia (Piperaceae) inferred from the trnK/matK region (cpDNA)

The genus Peperomia is one of the largest genera of basal angiosperms, comprising about 1500-1700 pantropically distributed species. The currently accepted infrageneric classification divides Peperomia into nine subgenera and seven sections. This classification is based on some 200 species, primarily using fruit morphology. The monophyly of these infrageneric taxa has never been tested and molecular phylogenetic studies of a representative sampling within Peperomia do not exist. This paper provides the first molecular phylogeny for the genus Peperomia. Monophyletic clades within Peperomia are identified and previously used morphological characters are critically reviewed. We show that the importance of some morphological characters has been overestimated and that some of these characters presumably have evolved several times independently. Only one previously described subgenus has been confirmed to be monophyletic.     

Two new saponins from Paronychia capitata

Two new oleanane-type triterpene glycosides, 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→2)˗β˗D˗xylopyranosyl˗(1→6)˗β˗D˗glucopyranosyl]medicagenic acid (1) and 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→6)˗β˗D˗glucopyranosyl˗(1→2)˗ β˗D˗xylopyranosyl]oleanolic acid (2), named capitatosides A and B respectively, were isolated from the butanol extract of Paronychia capitata (L.) Lam., along with seven known compounds. The structures of the isolated compounds were established by spectroscopic methods, mainly HRMS, 1D and 2D NMR (¹H, ¹³C, COSY, HSQC, HMBC and NOESY) techniques, whereas those of the known compounds were identified by spectral comparison with reported literature data.     

Vaxiations in floral development in Peperomia (Piperaceae) and their taxonomic implications

The floral development of two species of Peperomia, Peperomia reflexa A. Dietr. (P. tetraphylla (G. Font.) Hook. et Am.) and P. serpens C. DC., is described. The initiation order is in an acropetal succession and resembles that in P. metallica L. Lind. et Rod., P.pellucida (L.) Kunth and P. rubella Hook., although many more bracts are produced in these two species than in P. metallica. The arrangement of bracts and floral primordia is orthostichous in P. reflexa, but parastichous in P. serpens. The floral apices in P. reflexa are transversely ellipsoidal protuberances at first, then become saddle-shaped when they begin to produce simultaneously staminal primordia. They are similar to those of P. metallica, P. pellucida and P. rubella. However, their initiation of floral primordia is much delayed compared to the size of the bracts. The triangular or transvcrsely cuneate ridges then become L-shaped in P. serpens, this shape is related to the parastichous phyllotaxy of the bracts. So, the staminal primordia are successively initiated and develop at different rates. Therefore, they are not always the same size. The staminal primordia are initiated above the level of the floral apex in P. reflexa and P. serpens but below it in P. metallica, P. pellucida and P. rubella. The abaxial position of the carpel primordium on the apex and the closure of the ovary in P. reflexa and P. serpens are also similar to those in P. metallica, P. pellucida and P. rubella. The shape of the upper part of the ovary, stigmas and indumentum vary between the species. In P. reflexa, the upper part of the ovary becomes ovoid and acclivous, or leaning acropetally, to the axis of inflorescence. In P. serpens, it becomes helmet-shaped. The flowers of P.serpens are surrounded by the outgrowth of the axis of the inflorescence. The ontogenetical features of ovaries in Peperomia indicate that the fruit characters are useful in the taxonomy of the genus.     

Expression of P-Enolpyruvate Carboxylase and other Aspects of CAM during the Development of Peperomia camptotricha Leaves

During the development of Peperomia camptotricha leaves, metabolism changes from C₃-photosynthesis to Crassulacean acid metabolism (CAM). The youngest leaves showed no diurnal fluctuation of organic acids or P-enolpyruvate carboxylase (PEPc) activity. There was little evidence for PEPc protein using PEPc antibodies prepared from the CAM form of PEPc, nor was there evidence for PEPc mRNA when tested using a cDNA probe made from CAM P. scandens. As leaves matured, there was a parallel increase in titratable acidity, PEPc activity, PEPc protein, and PEPc mRNA. In leaf whorls 1 through 6, there was a significant linear correlation between the diurnal fluctuation of organic acids and PEPc activity indicating a functional relationship. The specific activity of PEPc increased as leaves matured and the K_m (PEP) decreased indicating that the enzyme was becoming more active. The ratio of PEPc protein to PEPc mRNA decreased as leaves matured. During the expression of CAM, the spongy mesophyll where most of the CAM activity occurs increased in thickness and per cent air space, whereas the palisade mesophyll where most of the C₃ activity occurs did not increase in size dramatically. The diurnal fluctuation of organic acids and the expression of PEPc activity, protein, and mRNA increased as the thickness of the spongy mesophyll increased. During the expression of CAM in Peperomia camptotricha, there appears to be coordinated expression of PEPc mRNA, protein, and activity, the commencement of diurnal organic acid fluctuation, and the development of the CAM-like spongy mesophyll. Thus the evidence suggests that CAM in this species is expressed during normal development and not in response to environmental signals.     

Two guaianolides from calea solidaginea

The isolation and structure elucidation of two new guaianolides, solidaginolides A(1) and B(5), from Calea solidaginea are reported. The structures of the new compounds were established by spectroscopic methods.     

Two new sterols from Physalis franchetii fruit

Two new steroids physanol A, 3β-benzoyloxy-6-oxo-stigmast-7,20-diene-11α-ol and physanol B, 3β-benzoyloxy-6-oxo-stigmast-7-ene-11α-ol have been isolated from the fruit of Physalis franchetti.     

Two New Isoprenylated Stilbenes from Artocarpus chama

Two new stllbenes with two Isoprenoid groups, namely artostllbenes A （compound 1） and B （compound 2）, were Isolated from the stems of Arfocarpus chama Buch.-Ham. by repeated column chromatography. The＆ structures were elucldated as （E）-4-[2-（7-meth-xy-2-2-d-methy-6-（3-methy-but-2-eny-）-2H-1-benz-pyran-5-y-）v-ny-]benzene-1- 2-dlol （compound 1） and （Z）-4-[2-（7-meth-xy-2-2-dimethy--6-（3-methy-but-2-eny-）-2H-1-benz-pyran-5-y-）v-ny-]ben- zene-l,2-dlol （compound 2） by spectroscopic methods, mainly by 1D-, 2D-NMR and MS spectra. Compounds 1 and 2 are two cls- and trans-lsomers and compound 2 is the flrst cis-stllbene isolated from Moraceous plants.     

Two New Norlignans and a New Lignanamide from Peperomia tetraphylla

Two new cyclobutane-type norlignans, methyl rel-(1R,2S,3S)-2-(7-methoxy-1,3-benzodioxol-5-yl)-3-(2,4,5-trimethoxyphenyl)cyclobutanecarboxylate (1), and methyl rel-(1R,2R,3S)-2-(7-methoxy-1,3-benzodioxol-5-yl)-3-(2,4,5-trimethoxyphenyl)cyclobutanecarboxylate (2), and a new lignanamide, 3-hydroxy-N-[2-(4-hydroxyphenyl)ethyl]-α-[4-(2-{N-[2-(4-hydroxyphenyl)ethyl]carbamoyl}ethenyl)-3-methoxyphenoxy]-4-methoxycinnamamide 4,8″-ether (3), along with five known amides, 4-8, were obtained from the whole plant of Peperomia tetraphylla. Their structures were elucidated mainly by the analysis of NMR and MS data. The new compounds 1-3 and the known compound 4 were tested for their cytotoxic activities against the HepG2 (human hepatocarcinoma), A549 (human lung cancer), and HeLa (human cervical cancer) cell lines. Compound 4 showed significant cytotoxicity against HepG2 cell lines with an IC(50) value of 9.4 ± 1.0?μM.