Withanolides and Sucrose Esters from Physalis neomexicana.

Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 µM, respectively.

Withanolides from Physalis hispida.

Nine new withanolides (1-9), withahisolides A-I, were isolated along with nine known compounds (10-18) from the aerial parts of Physalis hispida. The structures of 1-9 were elucidated through a variety of spectroscopic techniques, while the structures of 1 and 2 were confirmed by X-ray crystallographic analysis. Compounds 1-3 are the first withanolides with nonaromatic six-membered ring D moieties. In addition, withanolide 8 represents a novel withanolide skeleton due to the absence of a C-13-C-17 bond within the steroidal nucleus.

Withanolide artifacts formed in methanol.

Methanol solutions of the main withanolides (6-8) naturally present in Physalis longifolia yielded five artificial withanolides (1-5), including three new compounds (1-3). Withanolides 1 and 2 were identified as intramolecular Michael addition derivatives, while withanolides 3-5 were the result of intermolecular Michael addition. A comprehensive literature investigation was conducted to identify potential withanolide Michael addition artifacts isolated from Solanaceous species to date.

Two new flavan-flavanones from Sarcandra hainanensis.

Chemical study of the whole plants of Sarcandra hainanensis yielded two new biflavonoids with a flavan-flavanone skeleton, sarcandrone C (1), D (2) and 6 known compounds (3-8). Structures were elucidated on the basis of NMR spectroscopic methods.

[Advance in on chemical constituent and bioactivity research of genus Chloranthus].

Progresses in the studies on chemical constituents and bioactivities of Chloranthus S. were systemically reviewed in this article. The whole plants of most species in Chloranthus have long been used as folk medicine in China for detumescence, treating on snake bite and wound. 68 compounds obtained from the plants in Chloranthus fall into the following compound classes: terpenoids, coumarins, amides, organic acids and sterols. Fifty one sesquiterpenes were got. The results of studies on their bioactivities show that most of the plants in this genus have antibacterial and antitumor activities. Further phytochemical and biological studies on the species in Chloranthus are needed for better medicinal utilization.

Two new taxanes from the needles and branches bark of Taxus cuspidata.

Two new taxanes were isolated from the MeOH extract of the needles and branches bark of the Japanese yew, Taxus cuspidata. The structures were established as (2alpha,5alpha,7beta,9alpha,10beta,13alpha)-5,10,13,20-tetraacetoxytax-11-ene-2,7,9-triol (1) and (2alpha,5alpha,9alpha,10beta)-2,9,10-triacetoxy-5-[(beta-D-glucopyranosyl)oxy]-3,11-cyclotax-11-en-13-one (2) on the basis of in-depth 1D- and 2D-NMR analyses. Compound 2 is the first example of a transannular taxane glycoside isolated from a natural source.

Four new epoxy taxanes from needles of Taxus cuspidata (Taxaceae).

Four new epoxy taxoids were isolated from the needles of Taxus cuspidata. Their structures were established as 2a,9a-diacetoxy-5a-cinnamoyloxy-11,12-epoxy-10ss-hydroxytax-4(20)-en-13-one (1), 2a,10ss-diacetoxy-5a-cinnamoyloxy-11,12-epoxy-9a-hydroxytax-4(20)-en-13-one (2), 2a,9a-diacetoxy-11,12-epoxy-10ss,20-dihydroxytax-4-en-13-one (3) and 2a,10ss-diacetoxy-11,12-epoxy-9a,20-dihydroxytax-4-en-13-one (4) on the basis of spectral analysis including 1H-NMR, 13C-NMR, 1H-1H-COSY, HSQC, HMBC and HRFABMS. Compounds 3 and 4 are the first example of 11,12-epoxy taxoids with C-4 double bond found in T. cuspidata.

[Studies on chemical constituents in heartwood of Taxus cuspidata].

OBJECTIVE: To study the chemical constituents in the heartwood of Taxus cuspidata. METHOD: Silica gel column chromatography, preparative HPLC and preparative TLC were used to isolate and purify the chemical constituents; 1H- and 13C-NMR spectroscopic methods were used for structural identification. RESULT: Ten compounds, taxinine (1), taxusin (2), beta-sitosterol (3), 1 beta-hydroxybaccatin I (4), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl) butanoyloxy-4 (20), 11-taxadiene (5), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl-3'-hydroxy-butanoyloxyl-4 (20), 11-taxadiene (yunnanxane) (6), 9alpha, 10beta, 13alpha-triacetoxy-5alpha-cinnamoyltaxa-4 (20), 11-diene (7), 2-deacetoxytaxinine J (8), taxezopidine G (9), 2alpha, 7beta, 9alpha, 10beta, 13alpha-pentaacetoxyl-taxa-4 (20), 11-dien-5-ol (5-decinnamoyltaxinine J) (10), were isolated and identified from the heartwood of T. cuspidata. CONCLUSION: Three taxanes, 1 beta-hydroxybaccatin I (4), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl-3'-hydroxy-butanoyloxy)-4 (20), 11-taxadiene (yunnanxane) (6), and 2alpha, 7beta, 9alpha, 10beta, 13alpha-pentaacetoxyltaxa-4 (20) , 11-dien-5-ol (10), were obtained from this plant for the first time.

Withanolides from Physalis coztomatl.

Six withanolides (1-6), as well as two known withanolides (physachenolide D 7 and withanoside VI 8), were isolated from the aerial parts of Physalis coztomatl (Solanaceae). Structural elucidations of 1-6 were achieved through 2D NMR and other spectroscopic techniques, while the structure of 1 was confirmed by X-ray crystallographic analysis. In addition, the stereochemical orientation of the 17-hydroxy group in withanolides was discussed in relation to (13)C NMR shifts of C-12, 13, 14 and 16. Such analysis established that coagulansin A contains a 17α-hydroxy moiety rather than the reported 17ß-hydroxy functionality, and has been revised accordingly.

Analysis of Major Withanolides in Physalis longifolia Nutt. by HPLC-PDA.

An analytical method based on high-performance liquid chromatography-photodiode array detection was developed for the simultaneous determination of three anti-proliferative withanolides [withalongolide A ( 1: ), withaferin A ( 2: ) and withalongolide B ( 3: )] present in the aboveground biomass of the long-leaf groundcherry, Physalis longifolia. This method was achieved by biomass extraction followed by chromatographic separation on C18 column eluted with a gradient acetonitrile-water mobile phase. Calibration curves produced satisfactory linear regression (r(2) > 0.9995) for each examined sample. The method was also validated for accuracy, precision and limits of detection and quantification. Such an approach is applicable for the rapid detection and quantitative assessment of withanolides in various P. longifolia accessions.

Antiproliferative withanolides from several solanaceous species.

To date, our work on solanaceous species (Datura wrightii, Jaborosa caulescens, Physalis hispida, Physalis longifolia, Vassobia breviflora and Withania somnifera) has resulted in the isolation of 65 withanolides, 31 of which were new, as well as the semi-synthesis of a further 30 withanolides. Structure identification and MTS assay-based antiproliferative evaluation of these 95 compounds revealed that a Δ(2)-1-oxo functionality in ring A, in conjunction with either a 5ß,6ß-epoxy or 5α-chloro-6ß-hydroxy moiety in ring B, is the minimum structural requirement for withanolides to produce potent cytotoxic activity. Such structure-activity relationship analysis also revealed that oxygenation (the -OH or -OR groups) at C-4, 7, 11 and 12, as well as C-14 to C-28, did not contribute towards the observed antiproliferative activity. Herein, we present a complete overview of our work as it relates to the withanolides reported from 1965 to 2013.

Withanolides from Jaborosa caulescens var. bipinnatifida.

Withanolides 2,3-dihydrotrechonolide A (1) and 2,3-dihydro-21-hydroxytrechonolide A (2) were isolated along with two known withanolides trechonolide A (3) and jaborosalactone 39 (4) from Jaborosa caulescens var. bipinnatifida (Solanaceae). The structures of 1-2 were elucidated through 2D NMR and other spectroscopic techniques. In addition, the structure of withanolide 1 was confirmed by X-ray crystallographic analysis.

Low-temperature conditioning of "seed" cloves enhances the expression of phenolic metabolism related genes and anthocyanin content in 'Coreano' garlic (Allium sativum) during plant development.

Low-temperature conditioning of garlic "seed" cloves accelerated the development of the crop cycle, decreased plant growth, and increased the synthesis of phenolic compounds and anthocyanins in the outer scale leaves of the bulbs at harvest time, leading to 3-fold content increase compared with those conditioned at room temperature. Cold conditioning of "seed" cloves also altered the anthocyanin profile during bulb development and at harvest. Two new anthocyanins are reported for the first time in garlic. The high phenolics and anthocyanin contents in bulbs of plants generated from "seed" cloves conditioned at 5 °C for 5 weeks were preceded by overexpression of some putative genes of the phenolic metabolism [6-fold for phenylalanine ammonia lyase (PAL)] and anthocyanin synthesis [1-fold for UDP-sugar:flavonoid 3-O-glycosyltransferase (UFGT)] compared with those conditioned at room temperature.

A three-component gene expression system and its application for inducible flavonoid overproduction in transgenic Arabidopsis thaliana.

Inducible gene expression is a powerful tool to study and engineer genes whose overexpression could be detrimental for the host organisms. However, only limited systems have been adopted in plant biotechnology. We have developed an osmotically inducible system using three components of plant origin, RD29a (Responsive to Dehydration 29A) promoter, CBF3 (C-repeat Binding Factor 3) transcription factor and cpl1-2 (CTD phosphatase-like 1) mutation. The osmotic stress responsible RD29a promoter contains the CBF3 binding sites and thus RD29A-CBF3 feedforward cassette enhances induction of RD29a promoter under stress. The cpl1-2 mutation in a host repressor CPL1 promotes stress responsible RD29a promoter expression. The efficacy of this system was tested using PAP1 (Production of Anthocyanin Pigment 1) transgene, a model transcription factor that regulates the anthocyanin pathway in Arabidopsis. While transgenic plants with only one or two of three components did not reproducibly accumulate anthocyanin pigments above the control level, transgenic cpl1 plants containing homozygous RD29a-PAP1 and RD29a-CBF3 transgenes produced 30-fold higher level of total anthocyanins than control plants upon cold treatment. Growth retardation and phytochemical production of transgenic plants were minimum under normal conditions. The flavonoid profile in cold-induced transgenic plants was determined by LC/MS/MS, which resembled that of previously reported pap1-D plants but enriched for kaempferol derivatives. These results establish the functionality of the inducible three-component gene expression system in plant metabolic engineering. Furthermore, we show that PAP1 and environmental signals synergistically regulate the flavonoid pathway to produce a unique flavonoid blend that has not been produced by PAP1 overexpression or cold treatment alone.

Plants as biofactories: physiological role of reactive oxygen species on the accumulation of phenolic antioxidants in carrot tissue under wounding and hyperoxia stress.

Plants subjected to postharvest abiotic stresses synthesize secondary metabolites with health-promoting properties. Here, we report the potential use of carrots (Daucus carota) as biofactories of caffeoylquinic acids when subjected to wounding and hyperoxia stresses. Wounding stress induced an increase of ∼287% in total phenolic content (PC) in carrots stored for 48 h at 20 °C. This increase was higher (∼349%) in the wounded tissue treated with hyperoxia stress. To further understand the physiological role of reactive oxygen species (ROS) as a signaling molecule for the stress-induced accumulation of phenolics in carrots, the respiration rate as well as the enzymatic activities of NADPH oxidase, superoxide dismutase, ascorbate peroxidase, and catalase were evaluated. Likewise, shredded carrots were treated with diphenyleneiodonium chloride solution to block NADPH oxidase ROS productions, and the phenylalanine ammonia lyase activity and total PC were evaluated. Results demonstrated that ROS play a key role as a signaling molecule for the stress-induced accumulation of PC in carrots.

Two flavonoid dimers from Sarcandra hainanensis (PEI) SWAMY et BAILEY.

Two new flavonoid dimers (1, 2) consisting of flavan-chalcone together with three known compounds (3-5) were isolated from the ethanol extract of the whole plants of Sarcandra hainanensis. Their structures were determined by extensive spectroscopic analysis. Human immunodeficiency virus-1 integrase inhibition activities of compounds 1 and 2 were evaluated and they showed weak activities with IC(50) at 18.05 and 25.27 muM, respectively.