Xanthones with α‐Glucosidase Inhibitory Activities from Aspergillus versicolor,a Fungal Endophyte of Huperzia serrata

Three new xanthones, namely huperxanthones A–C ( 1 – 3 , resp.), were obtained from the cultures of Aspergillus versicolor, a fungal endophyte of Huperzia serrata, together with 1,7‐dihydroxy‐8‐(methoxycarbonyl)xanthone‐3‐carboxylic acid ( 4 ), β‐diversonolic acid methyl ester ( 5 ), 4‐hydroxyvertixanthone ( 6 ), and sydowinin B ( 7 ). The structures of the new compounds were established by detailed NMR and MS analysis, especially by 2D‐NMR experiments. All xanthones were evaluated for their effects on α‐glucosidase. Compound 4 exhibited a potent inhibitory activity against α‐glucosidase with an IC₅₀ value of 0.24 mM (vs. 0.38 mM for acarbose). The rest of the compounds showed weak or no activity against α‐glucosidase.     

Rare C25 Steroids Produced by Penicillium chrysogenum P1X,a Fungal Endophyte of Huperzia serrata

Three new metabolites, norcyclocitrinol A ( 1 ), erythro‐11α‐hydroxyneocyclocitrinol ( 2 ), and pesudocyclocitrinol A ( 3 ), along with six known analogs, i.e., neocyclocitrinols A–D ( 4 – 7 , resp.), cyclocitrinol ( 8 ), and 24‐epicyclocitrinol ( 9 ), were isolated and identified from the culture broth of Penicillium chrysogenum P1X, a fungal endophyte of Huperzia serrata. Compounds 1 – 9 were identified by spectroscopic methods to share the same C₂₅‐steroid skeleton featuring an unusual bicyclo[4.4.1] A/B ring system. In particular, 1 represents the first example of a C₂₅ steroid with a bisnor C‐atom side chain. All compounds were evaluated for their cytotoxic activities against HeLa and HepG2 cell lines. However, none of them exhibited a significant cytotoxicity at a concentration of 20 μM .     

Diketopiperazine Alkaloids from Penicillium spp. HS‐3, an Endophytic Fungus in Huperzia serrata

Cultivation of the fungus Penicillium spp. HS‐3, an endophytic fungus from the stems of Huperzia serrata, led to the isolation of a new diketopiperazine alkaloid, named as tryhistatin ( 1 ), together with three known ones, 2 – 4 , all of which share a similar backbone. The structure of 1 was established by detailed interpretation of the 1D‐ and 2D‐NMR spectra, and HR‐ESI‐MS data. Furthermore, 1D‐ and 2D‐NMR experiments were employed to elucidate the structure of 2 which was deduced previously only on the basis of the LC/MS method. In this article, we confirmed the correctness of the previously reported structure and made a complete assignment of the NMR signals of 2 for the first time.     

Huperzine V, A New Lycopodium Alkaloid from Huperzia serrata

Huperzine V, a new Lycopodium alkaloid, was isolated from the whole plant of Huperzia serrata, and the absolute stereochemistry was determined by X-ray crystallographic analysis.     

N‐Bearing Furanone Derivatives from an Endophytic Fungus in Huperzia serrata

Two new polyketide derivatives, huaspenones C and D ( 1 and 2 , resp.), were isolated from the cultures of an endophytic fungus Peyronellaea sp. HS‐12, derived from the stems of Huperzia serrata. They share N‐bearing furan‐3(2H)‐one backbone, and 2 has an unprecedented furo[3,2‐c]pyridine skeleton. Their structures including the absolute configuration were elucidated by extensive spectroscopic analysis combined with quantum‐chemical calculations. (2E,4E)‐6‐hydroxy‐2‐methylocta‐2,4‐dienoic acid ( 3 ), a key intermediate of the biosynthesis of 1 and 2 , was also obtained from the endophyte.     

Huperzine W,a Novel 14 Carbons Lycopodium Alkaloid from Huperzia serrata

Lycopodium plants have long been studied and many alkaloids have been reported thus far. Most of the compounds reported have a common formula of C16N1. During the course of chemical investigation on Huperzia serrata, we gained huperzine W (1, 25 mg from 10 kg dry whole plant), a novel compound which possessed a unique structure among Lycopodium alkaloids, along with a known compound, alopecuridine (2)2. In present paper, we report on the isolation and structural elucidation of 1. 1 2 H…     

Huperzine H, a New Lycopodium Alkaloid from Huperzia serrata

Huper:iaserrata(Thunb.)Trev.isoneofthemostcommonlyusedtraditionalChineseherbalmedicinesforthetreatmentofcontusions,strains,swellingsandschirophremas'etc..Manylycopodiumalkaloidshavebeenisolated2'3fromitincludinghuperzineA,acompoundwhichhasshownpotentialeffectsonAlzheimedisease.Inourinvestigations.threenewlycopodiumalkaloidswereobtainedandreported"'.ThispaperdealswiththeidentificationofhuperzineH--anewlycopodiumalkaloidwithanovelskeleton.HLlperzineHiscolorlessneedleswithIQ].-216(c0.02.CHC…     

Huperzine A production by Paecilomyces tenuis YS-13, an endophytic fungus isolated from Huperzia serrata

Huperzine A (HupA), a naturally occurring alkaloid in the plant family Huperziaceae, has drawn great interest for its potential application in Alzheimer disease therapy. Our primary objective was to identify alkaloid- and HupA-producing fungi from the Chinese folk herb, Huperzia serrata. We established a rapid and efficient model for screening HupA-producing endophytic fungal strains. The presence of HupA in Paecilomyces tenuis YS-13 was analysed by thin-layer chromatography, high-performance liquid chromatography and mass spectrometry. The fermentation yield of HupA was 21.0 μg/L, and the IC₅₀ of the crude extract of YS-13 fermentation broth was 1.27 ± 0.04 mg/mL. This is the first report of P. tenuis as a HupA-producing endophyte isolated from Huperziaceae.     

A new alkaloid and arbutin from the whole plant of Huperzia serrata

A new Lycopodium alkaloid together with a phenolic glyco-side-arbutin, were isolated from the whole plant of Huperzia serrata. The new compound was assigned the trivial name of huperzine I. The structures of these two compounds were determined on the basis of spectral evidence.     

Furanone Derivatives from Aspergillus sp. XW‐12, an Endophytic Fungus in Huperzia serrata

Two new 5‐methoxyfuran‐3(2H)‐one derivatives, huaspenone A ( 1 ) and B ( 2 ), together with four known ones, i.e., aspertetronin A ( 3 ), aspertetronin B ( 4 ), gregatin E ( 5 ), and penicilliol A ( 6 ), were isolated from the cultures of an endophytic fungus Aspergillus sp. XW‐12, derived from the stems of Huperzia serrata. The structures of the new isolates were established by detailed interpretation of the 1D‐ and 2D‐NMR and HR‐ESI‐MS data.     

Endophytic Fungal Community of Huperzia serrata: Diversity and Relevance to the Production of Huperzine A by the Plant Host

As the population ages globally, there seem to be more people with Alzheimer’s disease. Unfortunately, there is currently no specific treatment for the disease. At present, Huperzine A (HupA) is one of the best drugs used for the treatment of Alzheimer’s disease and has been used in clinical trials for several years in China. HupA was first separated from Huperzia serrata, a traditional medicinal herb that is used to cure fever, contusions, strains, hematuria, schizophrenia, and snakebite for several hundreds of years in China, and has been confirmed to have acetylcholinesterase inhibitory activity. With the very slow growth of H. serrata, resources are becoming too scarce to meet the need for clinical treatment. Some endophytic fungal strains that produce HupA were isolated from H. serrate in previous studies. In this article, the diversity of the endophytic fungal community within H. serrata was observed and the relevance to the production of HupA by the host plant was further analyzed. A total of 1167 strains were obtained from the leaves of H. serrata followed by the stems (1045) and roots (824). The richness as well as diversity of endophytic fungi within the leaf and stem were higher than in the root. The endophytic fungal community was similar within stems as well as in leaves at all taxonomic levels. The 11 genera (Derxomyces, Lophiostoma, Cyphellophora, Devriesia, Serendipita, Kurtzmanomyces, Mycosphaerella, Conoideocrella, Brevicellicium, Piskurozyma, and Trichomerium) were positively correlated with HupA content. The correlation index of Derxomyces with HupA contents displayed the highest value (CI = 0.92), whereas Trichomerium showed the lowest value (CI = 0.02). Through electrospray ionization mass spectrometry (ESI-MS), it was confirmed that the HS7-1 strain could produce HupA and the total alkaloid concentration was 3.7 ug/g. This study will enable us to screen and isolate the strain that can produce HupA and to figure out the correlation between endophytic fungal diversity with HupA content in different plant organs. This can provide new insights into the screening of strains that can produce HupA more effectively.     

高效液相色谱法定量测定中药千层塔提取物中的石杉碱甲

建立了高效液相色谱快速定量测定中药千层塔提取物中石杉碱甲含量的分析方法。千层塔提取物经甲醇/水/甲酸(10/90/0.2, v/v/v)提取并定容后,过滤膜后直接分析。色谱分离选用XCharge C18色谱柱(150 mm×4.6 mm, 5 μm),以水(含0.1%三氟乙酸)和乙腈(含0.09%三氟乙酸)为流动相进行梯度洗脱,流速为2 mL/min,于310 nm波长下检测,可在10 min内完成石杉碱甲的快速分离分析。结果表明,石杉碱甲在2.12～106 mg/L范围内线性关系良好(相关系数为0.9999);平均加标回收率为102.34%,相对标准偏差(RSD)为0.46%;日内及日间精密度均小于2%,满足定量要求。该方法简便、快速,结果可靠,重现性好,可作为千层塔提取物质量评价的依据。     

Artabotryols A – E,New Lanostane Triterpenes from the Seeds of Artabotrys odoratissimus

Six new lanostane triterpenes, artabotryols A, B, C1, C2, D, and E ( 1, 2, 3a, 3b, 4 , and 5 , resp.) have been isolated from the seeds of Artabotrys odoratissimus (Annonaceae). Their structures have been established as (3α,22S,25R)‐3‐hydroxy‐22,26‐epoxylanost‐8‐en‐26‐one ( 1 ), (3α,22S,25R)‐22,26‐epoxylanost‐8‐ene‐3,26‐diol ( 2 ), (3α,22S,25R,26R)‐26‐methoxy‐22,26‐epoxylanost‐8‐en‐3‐ol ( 3a ), (3α,22S,25R, 26S)‐26‐methoxy‐22,26‐epoxylanost‐8‐en‐3‐ol ( 3b ), (3α,22S,25R)‐3,22‐dihydroxylanost‐8‐en‐26‐oic acid ( 4 ) and (3α,7α,11α,22S,25R)‐3,7,11‐trihydroxy‐22,26‐epoxylanost‐8‐en‐26‐one ( 5 ) by spectroscopic studies and chemical correlations.     

Combretins A and B,New Cycloartane‐Type Triterpenes from Combretum fragrans

The phytochemical studies on the leaves of the traditionally used medicinal plant Combretum fragrans F. Hoffm (Combretaceae) from Cameroon have led to the isolation of combretins A and B ( 1 and 2 , resp.), two new cycloartane‐type triterpenes from the AcOEt‐soluble subfraction along with β‐sitosterol ( 3 ), oleanolic acid ( 4 ), ursolic acid ( 5 ), and pratensein ( 6 ). The compounds 4  –  6 are reported for the first time from this species. The structures of the new triterpenes were elucidated by spectroscopic techniques including ¹H‐ and ¹³C‐NMR (DEPT), and 2D‐NMR experiments.     

A New Peroxy‐multiflorane Triterpene Ester from the Processed Seeds of Trichosanthes kirilowii

A new peroxy‐multiflorane triterpene ester, (3α,5α,8α,20α)‐5,8‐epidioxymultiflora‐6,9(11)‐diene‐3,29‐diol 3,29‐dibenzoate ( 1 ), was isolated from the processed seeds of Trichosanthes kirilowii, together with the two known related derivatives 2 and 3 , and the two known steroids 4 and 5 . Compounds 2, 4 , and 5 were isolated from the genus Trichosanthes for the first time. The structure of compound 1 was established by NMR, HR‐MS, and CD analyses. Compounds 1 – 3 were tested for their in vitro cytotoxicity against human‐tumor cell lines (Hela, HL‐60, and MCF‐7) and anti‐inflammatory activity (LPS‐induced B lymphocyte cells) with the MTT method.     

13C,13C coupling constants from a mixture of isotopomers (13C) of substituted aromatic compounds; 1-nitronaphthalenes

¹³C Homonuclear decoupling experiments led to the assignment of the carbon-carbon coupling constants of ¹³C-enriched 1-nitronaphthalene obtained by nitration of [1-¹³C]naphthalene. The effects of substituents on coupling constants can be explained on the basis of the electronegativity of the first atom of the substituent, and the observed substituent effects are shown to be parallel to previous data for oxygen containing substituents.     

Rational Design of [13C,D14]Tert‐butylbenzene as a Scaffold Structure for Designing Long‐lived Hyperpolarized 13C Probes

Dynamic nuclear polarization (DNP) is a technique to polarize the nuclear spin population. As a result of the hyperpolarization, the NMR sensitivity of the nuclei in molecules can be dramatically enhanced. Recent application of the hyperpolarization technique has led to advances in biochemical and molecular studies. A major problem is the short lifetime of the polarized nuclear spin state. Generally, in solution, the polarized nuclear spin state decays to a thermal spin equilibrium, resulting in loss of the enhanced NMR signal. This decay is correlated directly with the spin‐lattice relaxation time T₁. Here we report [¹³C,D₁₄]tert‐butylbenzene as a new scaffold structure for designing hyperpolarized ¹³C probes. Thanks to the minimized spin‐lattice relaxation (T₁) pathways, its water‐soluble derivative showed a remarkably long ¹³C T₁ value and long retention of the hyperpolarized spin state.     

Total Syntheses of Xiamycins A,C, F,H and Oridamycin A and Preliminary Evaluation of their Anti‐Fungal Properties

Divergent and enantiospecific total syntheses of the indolosesquiterpenoids xiamycins A, C, F, H and oridamycin A have been accomplished. The syntheses, which commence from (R)‐carvone, employ a key photoinduced benzannulation sequence to forge the carbazole moiety characteristic of these natural products. Late‐stage diversification from a common intermediate enabled the first syntheses of xiamycins C and F, and an unexpected one‐pot oxidative decarboxylation, which may prove general, led to xiamycin H. All synthetic intermediates and the natural products were tested for anti‐fungal activity. Xiamycin H emerged as an inhibitor of three agriculturally relevant fungal pathogens.