查看更多>>摘要:? 2022Two new angular-type pyranocoumarins, namely hyuganin G (1) and hyuganin H (2), were isolated from an ethyl acetate extract of the aerial parts of Angelica furcijuga, together with three known angular-type pyranocoumarins, isoepoxypteryxin (3), isopteryxin (4), and hyuganin E (5). Assignment of the 1H and 13C NMR data of 1 and 2 were achieved via analysis of the DEPT, HMQC, and HMBC spectra. The absolute configurations of 1 and 2 were determined by semi-synthesis from 3.
查看更多>>摘要:? 2022 Phytochemical Society of EuropeTwo new sesquiterpenoids (1 and 2) and one new p-coumaroyl-triterpenoid derivative (3), along with five known sesquiterpenoids (4–8), seven triterpenoids (9–15), and two steroids (16 and 17) were isolated from Myrcia guianensis. Compound 1 [6-methyl-5-(2-hydroxy-3-chloro-5-methyl phenyl)-heptan-2-one] contains a chlorine atom attached to C-10, which seems to be the first report of a chlorine-containing sesquiterpenoid in the Myrtaceae family. The biogenesis of the two new sesquiterpenoids (1 and 2) are proposed herein, whereas the isolation of these sesquiterpenoids and triterpenoids from M. guianensis may present chemophenetic relevance to consolidate the genus Myrcia within the Myrtaceae family.
查看更多>>摘要:? 2022 Phytochemical Society of EuropeIn this study, three new compounds (1-3), together with fifteen known ones (4-18) were isolated from a petroleum ether extract of the roots of Eupatorium chinense. The structures of new compounds were elucidated by 1D, 2D nuclear magnetic resonance (NMR), circular dichroism spectrum (CD), mass spectrum (MS) along with other spectroscopy methods. In addition, twelve compounds were evaluated in vitro for their anti-inflammatory activities, while compounds 3 and 5 exhibited moderate activities with inhibition rates of 23.08 % and 25.19 %, respectively.
查看更多>>摘要:? 2022 Phytochemical Society of EuropePhenylalanine ammonia-lyase (PAL), which is ubiquitous in plants, catalyzes the formation of trans-cinnamic acid via the nonoxidative deamination of L-phenylalanine. Bambusa oldhamii contains four different forms of PAL proteins that differ in substrate specificity. Full-length BoPAL3 cDNA was cloned by a combination bamboo cDNA library screening and PCR-based cloning methods. Sequence alignment showed high homology between the deduced amino acid sequences of the BoPAL2 and BoPAL3 proteins (90%). Obvious PAL and tyrosine ammonia-lyase (TAL) activities were detected in Escherichia coli Top10 expressing recombinant BoPAL3 protein. Size-exclusion chromatography and denatured SDS–PAGE showed that the estimated molecular mass of recombinant BoPAL3 and the subunit form were approximately 330 kDa and 80 kDa, indicating that BoPAL3 presents as a tetrameric protein. The optimum temperature and pH for BoPAL3 activity were 50 °C and 8.5, respectively. The Km value of BoPAL3 for L-phenylalanine was 200 μM.
查看更多>>摘要:? 2022 Phytochemical Society of EuropeA phytochemical investigation performed on the leaves of Daphniphyllum himalaense has led to the characterization of two new amino sugars (1 and 2) and six known daphniphyllum alkaloids. The structures of new compounds were determined based on the interpretation of spectroscopic data. Some of the alkaloids were found to possess moderate to weak activity against the hepatitis C virus infection.
查看更多>>摘要:? 2022 Phytochemical Society of EuropePhytochemical investigation of a 90 % ethanol extract of Pachysandra terminalis Sieb. Et Zucc led to the isolation of a novel alkaloid, terminamine T (1); a new pregnane-type alkaloid, terminamine U (2); and four known pregnane-type alkaloids (3-6). The structures of these compounds were elucidated on the basis of nuclear magnetic resonance spectra, mass spectrometry data, single-crystal X-ray diffraction, and by a comparison with data from the literature. All compounds were evaluated for their antibacterial activities against gram-positive (S. aureus, ATCC 29213) and gram-negative (E. coli, ATCC 25922) bacteria. Compounds 2-6 exhibited generally modest to poor antibiotic properties. Furthermore, compound 2 showed antibacterial activity against methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus aureus USA300 (LAC) with a minimal inhibitory concentration (MIC) value of 32 μg/mL (75 μM) and minimum bactericidal concentration (MBC) values of 64, 128, and 128 μg/mL (150, 300, and 300 μM), respectively.
查看更多>>摘要:? 2022 Phytochemical Society of EuropeThe first isolation of a trachylobane from an African specimen of Psiadia punctulata (Asteraceae) is presented in this paper. A complete 1H and 13C NMR spectral analysis of this compound and two other trachylobane diterpenes, previously isolated from the same plant, are also provided. The use of NMR techniques such as gCOSY, gHSQC, gHMBC and 2D-J-resolved, in combination with a software-assisted methodology, led to a complete and unequivocal assignment of 1H and 13C signals. This was achieved together with the measurement of all homonuclear hydrogen coupling constants. The presented detail level of the assignment data has never been published before for trachylobanes. Furthermore, with all determined NMR experimental data from the spectra and to obtain a reliability assessment, signals were simulated in the FOMSC3 and NMR_MultSim software.
查看更多>>摘要:? 2022 Phytochemical Society of EuropeFour new patchoulol-type sesquiterpenoids, including 6α,9β-dihydroxypatchoulol 6-O-β-D-glucopyranoside (1), 6α-hydroxypatchoulol 6-O-β-D-glucopyranoside (2), 3α,9β-dihydroxypathoulol (3), and 4β-hydroxynorpatchoulol 4-O-β-D-glucopyranoside (10), were isolated from the roots of Pogostemon cablin (Blanco) Benth, together with eleven known sesquiterpenoids. Their structures were elucidated on the basis of extensive NMR spectral and high resolution mass spectrometry analysis. This is the second report of patchoulol glucopyranoside from P. cablin and compound 10 represented as the first example of nor-patchoulol glucopyranoside. The anti-influenza virus activities of 1–10 against A/WSN/33/2009 and A/Puerto Rico/8/1934 strains (tamiflu resistant viruses) were evaluated. Compounds 2β,12-dihydroxypathoulol (5) and (5R)-5-hydroxypatchoulol (8) exhibited moderate anti-influenza activity against A/WSN/33/2009 strain with EC50 value of 52.7 μM and 49.6 μM (positive control oseltamivir, EC50 = 6.75 μM). Compounds 8 and pogostol (12) showed potent anti-influenza activity against A/Puerto Rico/8/1934 strain with EC50 values of 3.06 μM and 0.07 μM, respectively, versus the postive control (amantadine, EC50 = 67.9 μM).
查看更多>>摘要:? 2022 Phytochemical Society of EuropeThe reaction of catharanthine with sodium borohydride in methylene chloride was claimed to produce an isomer of the title compound. A spectroscopic re-examination of the product has revealed that it is catharanthine borane.
查看更多>>摘要:? 2022 Phytochemical Society of EuropePhytochemical investigation of the whole plant of Hypericum curvisepalum led to the isolation of nine polycyclic polyprenylated acylphloroglucinols (1–9). Among them, curvisepalumiones A (1) and B (2) are two new compounds and their structures were elucidated based on extensive spectroscopic data analysis combined with Rh2(OCOCF3)4-induced electronic circular dichroism experiment. Cytotoxic assay showed that all the tested compounds except for 1 was moderately cytotoxic against human hepatocarcinoma cell line SMMC-7721 cell line, while compounds 3 and 4 also exhibited cytotoxicity toward MGC-803 cells. In addition, compound 2 exhibited weak inhibitory activity against Bacillus subtilis.