Benzofuranoid Neolignans from Piper kadsura

In a continuing research for neolignans from Piper kadsura (Choisy) Ohwi, six benzofuranoid neolignans were isolated from the aerial part of the plant. Their structure determination were based on the spectroscopic analysis (UV, IR, MS, NMR and CD) and derivative synthesis. Three of the isolated compounds were identified as new structures: 7R, 8R, 1′S-△8′-3, 4-methylenedioxy-5′-methoxy-l′, 4′-dihydro-4′-oxo-7, 0, 2′, 8. l′-neolignan ( Ⅰ ), 7 R, 8 R, 1 ′ R- △8′ - 3,4- methylenedioxy- 1 ′- methoxy - 1′,6′- dihydro- 6′- oxo- 7.0.4′,8. 3′-neolignan (Ⅳ) and 7R, 8R, 1′S-△8′-3, 4-methylenedioxy-l′-methoxy-1′,6′-dihydro-6′-oxo-7.0.4′,8.3′-neolignan (Ⅴ). Known compounds among them are 7R, 8S,1′S-△8′-3, 4-methylenedioxy-5′-methoxy-1′, 4′-dihydro-4′-oxo-7. 0. 2′, 8. 1′-neolignan(Ⅱ), 7S, 8S, 1′R-△8′-3, 4, 5′-trimethoxy-1′, 4′-dihydro-4′-oxo-7.0. 2′, 8. 1′-neolignan (Ⅲ) and 75, 85, 1′S-△8′-3, 4, l′-trimethoxy-l′, 6′-dihydro-6′-oxo-7. 0. 4′, 8. 3′-neolignans (Ⅵ). All of them were isolated from the plant for the first time.     

不同因子对林下细叶青蒌藤生长影响试验初报

用L9 (34)正交试验设计,分析造林方式、坡位和林冠层郁闭度对林下细叶青蒌藤生长的影响。结果表明,造林方式、坡位和林冠层郁闭度等因素对细叶青蒌藤的生物量鲜质量、总蔓长度和一级侧枝数量有显著影响。造林方式对细叶青蒌藤的主蔓基径有显著影响;促进生物量鲜质量、总蔓长度和一级侧枝数量的因子主次顺序均为造林方式、林冠层郁闭度、坡位;对主蔓基径因子影响主次顺序为造林方式、坡位、林冠层郁闭度。促进细叶青蒌藤生物量鲜质量、总蔓长度、一级侧枝数量与主蔓基径的最优组合均为：轻基质容器苗造林,下坡,林冠层郁闭度0.5～0.7。     

Chemical constituents of the Piper crocatum leaves and their chemotaxonomic significance

Chemical study of Piper crocatum leaves has led to isolation of a new megastigmane glucoside isomer (18), along with 23 known compounds including fifteen phenolic compounds (1–15), two monoterpenes (16 and 17), three sesquiterpenes (19–21), a phenolic amide glycoside (22), a neolignan (23), and a flavonoid C-glycoside (24). Structures of these compounds were identified via spectroscopic methods and compared with those reported in the literature. Seven compounds (7, 11, 13, 14, 17, 20, and 24) from the P. crocatum species and 17 others (1–6, 8–10, 12, 15–16, 18–19, and 21–23) from the Piper genus and Piperaceae family were isolated and reported for the first time. Furthermore, this study discusses chemotaxonomic relations between P. crocatum and other Piper species.     

Antifungal amides from Piper arboreum and Piper tuberculatum

In continuation of our study of the Piperaceae we have isolated several amides, mainly those bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. Bioactivity-guided fractionation of extracts from leaves of Piper arboreum yielded two new amides, N-[10-(13,14-methylenedioxyphenyl)-7(E),9(Z)-pentadienoyl]-pyrrolidine (1), arboreumine (2) together with the known compounds N-[10-(13,14-methylenedioxyphenyl)-7(E)-pentaenoyl]-pyrrolidine (3) and N-[10-(13,14-methylenedioxyphenyl)-7(E),9(E)-pentadienoyl]-pyrrolidine (4). Catalytic hydrogenation of 3 yielded the amide N-[10-(13,14-methylenedioxyphenyl)-pentanoyl]-pyrrolidine (5). We also have isolated six amides (6-11) and two antifungal cinnamoyl derivatives (12, 13) from seeds and leaves of Piper tuberculatum. Compounds 1-11 showed antifungal activity as determined by direct bioautography against Cladosporium sphaerospermum while compounds 3-4 and 6-13 also showed antifungal activity against C. cladosporioides.     

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7–24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC₅₀ values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H₃₇Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.     

Diuretic and antilithiasic activities of ethanolic extract from Piper amalago (Piperaceae)

ObjectivePiper amalago is used in Brazilian folk medicine as diuretic and for the treatment of urinary calculus disease, although no scientific data have been described to support these effects. Thus, this study aims to evaluate the diuretic effects and antilithiatic activity of the ethanolic extract of P. amalago (EEPam).Materials and methodsEthanolic extracts of P. amalago (125, 250 and 500 mg/kg) were orally administered in male Wistar rats (n = 5) and urinary excretion was measured at intervals of up to 24 h after administration. The antilithiasic effect of EEPam on calcium oxalate urolithiasis crystallization was examined in a turbidimetric model.ResultsThe oral administration of all doses of EEPam significantly increased urine output after 24 h when compared to control group. Moreover, the application of EEPam, induced an inhibitory effect on calcium oxalate crystallization.ConclusionsAccording to results, P. amalago extracts showed diuretic and natriuretic activity and antilithiasic effects.     

Circadian rhythm of anti-fungal prenylated chromene in leaves of Piper aduncum

Leaves of Piper aduncum accumulate the anti-fungal chromenes methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate (2). The enzymatic formation of 2 from dimethylallyl diphosphate and 1 was investigated using cell-free extracts of the title plant. An HPLC assay for the prenylation reaction was developed and the enzyme activity measured in the protein extracts. The prenyltransferase that catalyses the transfer of the dimethylallyl group to C-2' of 1 was soluble and required dimethylallyl diphosphate as the prenyl donor. In the leaves, the biosynthesis of the prenylated chromene 2 was time-regulated and prenyltransferase activity depended upon circadian variation. Preliminary characterisation and purification experiments on the prenyltransferase from P. aduncum have been performed.     

Antifungal flavanones and prenylated hydroquinones from Piper crassinervium Kunth

Bioactivity-guided fractionation of the EtOAc extract from leaves of Piper crassinervium yielded three prenylated hydroquinones together with two known flavanones naringenin and sakuranetin. Their structures were determined by means of spectroscopic analysis (NMR, IR, UV and MS) including two-dimensional NMR spectroscopy experiments (1H-1H COSY, HMQC, HMBC and NOESY). The antifungal activity was determined by direct bioautography against Cladosporium cladosporioides and C. sphaerospermum.     

Amides from Piper brachystachyum and Piper retrofractum

Three unsaturated amides, designated brachystamides-C, D and E have been characterised from Piper brachystachyum Wall. Brachystamide-C, shown to be N-isobutyl-15-(3',4'-methylenedioxyphenyl)-2E,4E,13E-pentadecatrienamide, was unusual in having a non-conjugated double bond. Piper retrofractum Vahl. yielded retrofractamide-D, which has been fully characterised.     

Piper protrusum (Piperaceae), a new species from southern Thailand based on morphological and molecular evidence

Abstract Piper protrusum Chaveer. & Tanee, sp. nov. is described and illustrated. It dominantly comprises three branching types with three different types of leaf blades, bases, and apexes. The critical distinguishing character is the protruded receptacle having a bract and nine stamens. Individual plants have been discovered in areas of Southern Thailand since 2004 without reproductive parts. The investigated sites were revisited several times, and an individual with flowers was finally found in July 2009. Phylogenetic analysis of the new species and five similar species is carried out based on DNA fingerprinting. The genetic distances between the new species and five similar species range from 0.25 to 0.35, supporting new species designation. Molecular data conform to morphological data in validating that it is a new species. Additionally, its DNA barcodes have been provided for further identification in case the morphological data is unclear. The sequence data have been submitted to the GenBank database under accession numbers GU980898 (rpoB gene), GU980899 (rpoC1 gene), and GU980900 (psbA‐trnH region).     

Synthesis and cytotoxic and analgesic activities of some 1, 5-diaryl-3-ethoxycarbonylpyrrole derivatives

Some 1,5-diaryl-3-ethoxycarbonyl-2-methylpyrrole derivatives were obtained by reacting 1-aryl-3-ethoxycarbonylpent-1,4-diones and a suitable aniline derivative or sulfanilamide under Paal-Knorr pyrrole synthesis conditions. The cytotoxicity of the compounds was tested and all compounds, except for compound 2 h, showed a time-dependent increase in cytotoxic activity. Analgesic activities of the compounds were determined by using the tail-flick and tail-immersion methods; some of the compounds showed potent analgesic activity.     

Evaluation of cytotoxic,antifungal, and larvicidal activities of different bis-sulfonamide Schiff base compounds

Schiff bases (imines or azomethines) are versatile ligands synthesized from the condensation of amino compounds with active carbonyl groups and used for many pharmaceutical and medicinal applications. In our study, we aimed to determine the cytotoxic, antifungal and larvicidal activities of biologically potent bis-sulfonamide Schiff base derivatives that were re-synthesized by us. For this aim, 16 compounds were re-synthesized and tested for their cytotoxic, antifungal and larvicidal properties. Among this series, compounds A1B2 , A1B4 , A4B2 , A4B3 , and A4B4 were shown to have cytotoxic activity against tested cancer lung cell line (A549). The most potent antifungal activity was observed in compounds A2B1 and A2B2 against all fungi. A1B1 showed the strongest larvicidal effect at all concentrations at the 72nd h (100% mortality). These obtained results demonstrate that these type of bis-substituted compounds might be used as biologically potent pharmacophores against different types of diseases.     

Novel indole-based melatonin analogues substituted with triazole,thiadiazole and carbothioamides: studies on their antioxidant,chemopreventive and cytotoxic activities

Melatonin (MLT) is a well-known free-radical scavenger, involving in the prevention of cellular damage that can lead to cancer, ageing and a variety of neurodegenerative diseases. Research on MLT-related compounds has been required to optimise the maximum pharmaceutical activity with the lowest side effects. In our ongoing research, we have synthesized new indole-based MLT analogues as potential antioxidant agents by modifying the MLT molecule. In this study, we build on previous findings, through the synthesis, characterization and in vitro antioxidant profiling of a series of new indole-based MLT analogues which possess triazole, thiadiazole and carbothioamides on the third position on the indole ring. In vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe and their radical scavenging activity was assessed via the DPPH assay. In addition, in vitro cytotoxic effects of newly synthesized compounds were investigated in CHO-K1 cells using the MTT assay.     

Chemical constituents from Oncocalyx glabratus and their biological activities

Chemical investigation of the aerial parts of Oncocalyx glabratus resulted in the isolation of three new flavan derivatives, 5,3′,4′-trihydroxyflavan 7-O-gallate (1), 5,4′-dihydroxyflavan 7-3′-O-digallate (2) and 5,3′-dihydroxyflavan 7-4′-O-digallate (3), named oncoglabrinol A, B and C, respectively, together with four known flavonols, (+)-catechin (4), (+)-catechin-7-O-gallate (5), catechin-7-4′-O-digallate (6A) and catechin-7-3′-O-digallate (6B). The structures of the compounds were established by 1D, 2D NMR and ESI-HRMS spectral analyses. The biological activity of the compounds was tested through a series of in vitro assays designed for determining cytotoxicity, antiviral activity against hepatitis B virus, and antidiabetic activity. All compounds were found non-toxic and showed moderate anti-HBV activity. Compounds 3 and 6 showed dual PPAR agonistic activity while others were not effective.     

Miscellaneous terpenoid constituents of Abies nephrolepis and their moderate cytotoxic activities

Three monoterpenoids and two triterpenoids were isolated from Abiesnephrolepis together with 53 known terpenoids. The structures of the compounds were established by 1D and 2D NMR spectroscopy. The absolute configuration of 3-hydroxycamphane-2-carboxylic acid was established as (1S,2R,3S,4R) by Cu-Kα X-ray crystallography. All 58 isolates were tested for cytotoxic activity against four tumor cells viz. A549 (human lung adenocarcinoma), Colo205 (colon adenocarcinoma), QGY-7703 (human hepatoma) and THP-1 (human monocytic leukemia). α-Cadinol exhibited the best effects on A549, Colo205 and QGY-7703 with IC₅₀ values of 8.6, 8.1 and 4.6 μg/mL, respectively.     

卡瓦胡椒及胡椒的RAPD聚类分析

目的：通过RAPD分析搞清楚卡瓦胡椒与胡椒及胡椒属其它近缘野生种的亲缘关系。方法和结果：采用随机引物80条进行筛选,用从80条随机引物中入选的20条引物,对卡瓦胡椒和胡椒属共计28份材料进行RAPD扩增,均能产生清晰的扩增谱带。重复1—2次,结果稳定可靠。20个引物共扩增出170个条带,其中多态性条带有20条,占总扩增条带数的12％。RAPD分析结果显示在相似系数0．36处对28份种质可划分为6个类型,其中卡瓦胡椒被单独聚为一类,说明卡瓦胡椒与胡椒及其它近缘野生种的亲缘关系有一定的距离。     

Synthesis of Gibbilimbols A-D,Cytotoxic and Antibacterial Alkenylphenols Isolated from Piper gibbilimbum

Gibbilimbols A [(E)-4-(4-decenyl)phenol, 1], B [(E)-4-(3-decenyl)phenol, 2], C [(E)-4-(4-octenyl)phenol, 3] and D [(E)-4-(3-octenyl)phenol, 4] were synthesized by coupling the phenolic parts with the alkyne parts and then reducing the triple bond of the resulting alkynylphenols. These alkenylphenols (1?4) are the cytotoxic and antibacterial constituents of the leaves of a medicinal plant (Piper gibbilimbum) that is used as a traditional medicine in Papua New Guinea.     

Essential Oils from Piper caldense C. DC. and Piper xylosteoides (Kunth) Steud.: Seasonal Variation of the Chemical Composition and Antimicrobial Activity

The essential oils (EOs) chemical composition can be affected by several environmental factors, impacting their desired biological activities. In this sense, this work aimed to evaluate the seasonal variation of the chemical composition and antimicrobial activity of Piper caldense and Piper xylosteoides leaves EOs. Their chemical composition was determined by GC/MS and GC-FID analyses, resulting in the identification of eighty compounds. P. caldense EOs were mainly consisted of sesquiterpene hydrocarbons, whereas in P. xylosteoides EOs, monoterpene hydrocarbons were predominant. EOs from both species strongly inhibited B. subtilis (MIC=0.25 mg mL⁻¹), while only P. caldense EOs showed strong activity against S. aureus (MIC=0.50 mg mL⁻¹). P. caldense spring EO showed the broadest spectrum of antimicrobial action amongst all samples. For each species, PCA seasonally differentiated EOs chemical composition. In addition, as expected, PCA of all samples showed a distinction between the two species. This study has successfully demonstrated the importance of evaluating the seasonal variation of EOs chemical composition and antimicrobial activity in obtaining a product with the desired properties.     

Trypanocidal tetrahydrofuran lignans from inflorescences of Piper solmsianum

In addition to sitosterol, syringaldehyde, 3,4,5-trimethoxybenzoic acid, isoelemicin and grandisin, two new tetrahydrofuran lignans were isolated from Piper solmsianun and characterized as rel-(7R,8R,7'R,8'R)-3',4'-methylenedioxy-3,4,5,5'-tetramethoxy-7,7'-epoxylignan and rel-(7R,8R,7'R,8'R)-3,4,3',4'-dimethylenedioxy-5,5'-dimethoxy-7,7'-epoxylignan on the basis of spectroscopic data, including 2D NMR spectrometric techniques. Their in vitro activity were determined against the trypomastigote form of Trypanossoma cruzi.