Andrographis paniculata (A. paniculata) is a traditional Chinese medicinal plant that accumulates andrographolide, a key bioactive diterpenoid compound. In this study, we found that light can upregulate the production of andrographolide. However, the underlying regulatory mechanisms governing its biosynthesis remain elusive. By coupling the RNA-seq data obtained under different light conditions with co-expression analysis, two candidate transcription factors, ApDof16 and ApDof29, were identified. Using virus-induced gene silencing (VIGS), we demonstrated that these two Dofs were able to regulate the content of andrographolide as well as the expression of ApCPS2, a key gene of the andrographolide biosynthesis pathway. Further experiments, such as the yeast one-hybrid (Y1H) assays, transient assays and chromatin immunoprecipitation quantitative PCR (ChIP-qPCR) analysis indicated that ApDof29 rather thanApDof16, directly binds to the promoter ofApCPS2, thereby regulating its expression and the subsequent andrographolide accumulation in response to light.
Plants have evolved various strategies to avoid inbreeding, but the mass flowering displayed by many plants predisposes them to within-plant pollen movements and self-pollination. Mistletoes often aggregate at multiple spatial scales. Their bird pollinators often visit several flowers of the same individual and of others on the same host tree. We hypothesized that hermaphroditic mistletoes have self-incompatibility mechanisms that reduce or prevent selfing. Whether their spatial distribution, affected by host specificity, host distribution, and the behaviour of seed dispersers, influences their mating system and population genetic structure remains unclear. We studied how mating system and spatial distribution affect genetic structure in four populations of the host-generalist mistletoe Dendrophthoe pentandra in southwestern China using microsatellite markers and progeny arrays. We also characterized the fine-scale spatial genetic structure among 166 mistletoes from four host trees in one population. Prevalence and intensity of infection both appeared to vary among host species, strongly affecting the degree of aggregation. Host tree size had a strong effect on infection intensity. Surprisingly, manual pollination experiments indicated that D. pentandra is self-compatible, but genetic analyses revealed that outcrossing rates were higher than expected in all four populations (MLTR tm 0.83-1.20, Bayesian tm 0.772-0.952). Spatial genetic structure was associated with distance between host trees but not at shorter scales (within hosts). Our results demonstrate that the combination of bird pollination, bird-mediated seed dispersal, and post-dispersal processes result in outcrossing and maintain relatively high diversity in the presence of biparental inbreeding, despite very high local densities and possible self-compatibility.
Five new thiohydantoin derivatives (1–5) were isolated from the rhizomes of Lepidium meyenii Walp. NMR (1H and 13C NMR, 1H−1H COSY, HSQC, and HMBC), HRESIMS, and ECD were employed for the structure elucidation of new compounds. Significantly, the structure of compound 1 was the first example of thiohydantoins with thioxohexahydroimidazo [1,5-a] pyridine moiety. Additionally, compounds 2 and 3 possess rare disulfide bonds. Except for compound 4, all isolates were assessed for neuroprotective activities in corticosterone (CORT)-stimulated PC12 cell damage. Among them, compound (−)-3 exhibited moderate neuroprotective activity (cell viability: 68.63%, 20 μM) compared to the positive control desipramine (DIM) (cell viability: 88.49%, 10 μM).
为探讨寄主多样性和寄主功能性状对桑寄生植物的寄主专一性的影响,调查了西双版纳热带植物园内桑寄生和寄主植物种类.结果表明,桑寄生植物共有2科5属6种1变种,感染隶属于58科190属286种寄主植物1323株.桑寄生在不同生境的寄生强度具有极显著差异(P<0.01),单一种植园的寄生强度最高,而在森林的分布最少.不同种类桑寄生的寄主范围存在较大差异,专一性程度(H?)为1.92~7.05,多度较高的植物更容易被感染.冗余分析表明,寄主植物的胸径、树皮含水量和树皮粗糙度对不同桑寄生的寄主利用差异有显著影响,而木质密度和树皮pH的影响不显著.因此,不同种类桑寄生在热带植物群落的寄主专一性程度有较大差异,对寄主植物特定功能性状的偏好能解释部分差异.
Nicandra physaloides is a medicinal and edible plant and has been used as traditionally herbal medicine to treat various diseases in folk. Its characteristic withanolides, a kind of ergostane-type steroids, are reported to display plentiful biological activities that many explain the effect of N. physaloides to some extent. Thus, to further find bioactive steroids, the stems and leaves of N. physaloides were investigated and three new C23 steroids, nic-physatones I-J (1-2), and nic-physatone S (3), together with a known C25 steroid, nic 17 (4), were isolated. Their structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, 1H-1H COSY, and ROESY), UV and MS analyses. Compounds 1-3 possess a rare C23 steroid skeleton. Among them, compound 3 represented the first example of a C23 steroid featuring a benzene ring (D ring). The isolated compounds showed no cytotoxic activity.
Four new B-seco-limonoids, toonamicronoids A–D (1–4), together with four known ones, toonaciliatin H–J (5–7), and toonacilianin A (8), were isolated from Toona microcarpa. Their structures were identified on the basis of ESIMS, HREIMS and 1D/2D NMR analysis. Compounds 1 and 4 showed moderate cytotoxicities against HL-60 with the IC50values of 17.3 ± 1.5 and 22.7 ± 1.9 μM, respectively.
Matsutakone (1), a novel sterol with an unprecedented polycyclic ring system, together with a new norsteroid matsutoic acid (2) were isolated from the fruiting bodies of Tricholoma matsutake. Their structures and absolute configurations were assigned by extensive spectroscopic analyses and computational methods. Bioassay results showed that compounds 1 and 2 exhibited inhibitory activities against acetylcholinesterase (IC50 20.9 μM for 1).
Two rare types of 4,6-dimethyl-3,4-dihydrochromen-2-one derivatives, named cralactones A and B (1 and 2), were isolated from the culture broth of Craterellus odoratus. The structures of the new ones were established on the basis of extensive spectroscopic analysis, and it was found that the new compounds did not show pancreatic lipase inhibitory activity. Compounds 1 and 2 are the first examples of 4,6-dimethyl-3,4-dihydrochromen-2-one.
(+)- and (−)-ganodilactone (1), a pair of novel meroterpenoid dimers possessing a unique 5′H-spiro[chroman-4,2′-furan]-2,5′-dione ring system were discovered from the fruiting bodies of Ganoderma leucocontextum.
Six new lanostane-type triterpenoids, namely leucocontextins S–X (1–6), together with twelve known compounds, were isolated from the fruiting bodies of Ganoderma leucocontextum. Their structures were established by MS and NMR data.
A variety of novel natural products with significant bioactivities are produced by the basidiomycete Boreostereum vibrans. In the present study, we describe 16 novel natural oximes and oxime esters with a vibralactone backbone, vibralactoximes, which were isolated from the scale-up fermentation broth of B.vibrans. Their structures were determined through extensive spectroscopic analyses. These compounds represent the first oxime esters from nature. The hypothetical biosynthetic pathway of these compounds was also proposed. Seven compounds exhibited significant pancreatic lipase inhibitory activity, while ten compounds exhibited cytotoxicities against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480), with IC50 values comparable with those of cisplatin.
Four new compounds, a dibenzylbutane lignin, plasiaticine F (1), an acetylenic glycoside, plasiaticine G (2), an indole alkaloid, plasiaticine H (3), and an ionone derivative, plasiaticine I (4), were isolated from the seeds of Plantago asiatica. The structures of the new compounds were elucidated on the basis of comprehensive analysis of spectroscopic data. Compounds 1-3 were tested for their cytotoxicity, but lacked significant activity.
Sesquiterpenoids are very common among natural products. A large number of sesquiterpene synthase genes have been cloned and functionally characterized. However, until now there is no report about the δ-cadinol synthase predominantly forming δ-cadinol (syn. torreyol) from farnesyl diphosphate. Sesquiterpenoids boreovibrins structurally similar to δ-cadinol were previously isolated from culture broths of the basidiomycete fungus Boreostereum vibrans. This led us to expect a corresponding gene coding for a δ-cadinol synthase that may be involved in the biosynthesis of boreovibrins in B. vibrans. Here we report the cloning and heterologous expression of a new sesquiterpene synthase gene from B. vibrans. The crude and purified recombinant enzymes, when incubating with farnesyl diphosphate as substrate, gave δ-cadinol as its principal product and thereby identified as a δ-cadinol synthase. A new sesquiterpene synthase gene was cloned from the basidiomycete fungus Boreostereum vibrans and heterologously expressed in E. coli. The purified recombinant enzyme gave δ-cadinol as its principal product from farnesyl diphosphate and thereby identified as a δ-cadinol synthase (BvCS).
以抗寒评比优良杂交榛子的叶片、茎段、腋芽、子叶为材料,采用不同基本培养基和不同激素及浓度组合,探讨各种处理对抗寒杂交榛子微体繁殖体系的影响.结果表明:(1)采用经抗寒性评比优良的杂交F1代10个优良品种进行组织培养,筛选出3个组织培养效果优良的品种84-226、84-310、84-253;(2)采用DKW、MS、WPM三种培养,筛选出WPM最适合抗寒杂交榛子愈伤组织诱导的培养基、MS为最适合增殖培养的培养基;(3)愈伤组织诱导基本培养基配方为WPM +6-BA 2.0 mg·L-1+ NAA 1.5 mg·L-1培养,腋芽扩繁以MS改良培养基苗生长状况较好,激素为6-BA 1.5mg·L-1 +NAA 0.1 mg·L-1.该研究可以解决寒地杂交榛子繁殖系数低,为进一步试管苗的工厂化生产提供理论依据.
Investigation on the cultures of Hypsizygus marmoreus resulted in the isolation of a new viscidane diterpene, 8-oxoviscida-3,11(18)-diene-13,14,15,19-tetraol (1) and two new polyacetylenes, (E)-10-(1,1-dimethyl-2-propenyloxy)-2-decene-4,6,8-triyn-1-ol (2) and 10-(1,1-dimethyl-2-propenyloxy)deca-4,6,8-triyn-1-ol (3), together with two known polyacetylenes, (E)-2-decen-4,6,8-triyn-1-ol (4) and 4,6,8-decatriyn-1-ol (5). Their structures were elucidated on the basis of extensive spectroscopic studies. Compound 1 is the first finding of viscidane diterpene in mushrooms. Compounds 1, 3 and 5 were tested for cytotoxicity against human tumor cell lines HL-60, SMMC-7721, A-549, MCF-7 and SW-480. None of the compounds showed cytotoxic activity (IC50 > 40 µM).
One new cleistanthane-type diterpene named engleromycenolic acid A (1), one new rosane-type diterpene named engleromycenolic acid B (2) and one new natural rosane-type diterpene, engleromycenol (3), along with three known rosane-type diterpenes, rosololactone (4), rosenonolactone (5) and 7-deoxyrosenonolactone (6) were isolated from cultures of the fungus Engleromyces goetzii, where it naturally grows on Alpine bamboo culms. The new compounds were elucidated based on their spectroscopic data. In addition, compounds 1–6 were evaluated for their cholesterol ester transfer protein (CETP) inhibition activity. This paper reports the isolation, structural elucidation, and CETP inhibition activity of these compounds.
Engleromyces goetzii is a traditional medicinal mushroom that is widely used to treat infection, inflammation and cancer in Tibet, Sichuan and Yunnan provinces of China. Two new trichothecenes, engleromycones A and B (1 and 2), one new cuparane-type sesquiterpenoid named infuscol F (11), eight known trichothecene analogs, sambucinol (3), 3-deoxysambucinol (4), trichothecolone (5), trichodermol (6), 8-deoxytrichothecin (7), trichothecin (8), trichothecinol B (9) and trichothecinol A (10), and one known cyclopentanoid sesquiterpene cyclonerodiol (12) were isolated from the cultures of E. goetzii. The new compounds were elucidated through spectroscopic analyses. The anticancer effects of trichothecenes 1–10 were examined in the HL-60, SMMC-7721, A549, MCF-7, and SW-480 human cancer cell lines using an MTT assay. Trichothecinol A (10) significantly inhibited the growth of MCF-7 cells, with an IC50 value of 0.006 µM, which was comparable to the cytotoxic activity of the positive control, paclitaxel, indicating that trichothecinol A (10) represents a potential anticancer agent.
Four new spiroaxane sesquiterpenes, tramspiroins A–D (1–4), one new rosenonolactone 15,16-acetonide (5), and the known drimane sesquiterpenes isodrimenediol (6) and funatrol D (7) have been isolated from the cultures of Basidiomycete Trametes versicolor. The structures of new compounds were elucidated by means of spectroscopic methods. Compounds 1–7 were investigated for their cytotoxicities against five human cancer cell lines.
Three new compounds, named as vibralactones K-M (1-3), together with vibralactone (4) have been isolated from cultures of the Basidiomycete Boreostereum vibrans. Their structures were determined on the basis of spectroscopic evidences (1D and 2D NMR, HRMS, UV, and IR data), chemical methods and literature data. None of the compounds was cytotoxic against five human cancer cell lines and showed inhibitory activity on the pancreatic lipase.
Acyl-ACP thioesterases are responsible for the export of fatty acids produced by the de novo fatty acid synthesis system from the plastid. A fatty acyl-acyl carrier protein thioesterase (CpFATB) was isolated from a Chimonanthus praecox (linn.) Link. (wintersweet) cDNA library. This gene was subsequently transferred into Populus deltoides CL 9 P. euramericana CL "NL895" through Agrobacterium tumefaciens-mediated leaf disc transformation. The transgenic plants were confirmed by polymerase chain reaction (PCR) analysis and Southern hybridization. Three positive transgenic lines each with a single T-DNA insertion were obtained. Reverse transcription PCR (RT-PCR) confirmed CpFATB expression in transformed plants after short-term exposure to drought. When exposed to drought stress, transgenic plants showed higher superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, chlorophyll a content, chlorophyll b content and total chlorophyll content compared with untransformed plants. Malondialdehyde (MDA) content, electric conductivity and net photosynthetic rate of the transgenic plants were lower than untransgenic plants. The results of physiological indices showed that the overexpression of CpFATB in plants exhibited higher drought stress tolerance under drought stress condition compared to the untransformed control plants. Our data further confirmed and highlighted the functions of CpFATB in enhancing plants drought tolerance and may provide a plausible approach to breed plants combating drought stress and enlarging living scope.