Phytochemical and biological studies on rare and endangered plants endemic to China. Part XXV. Structurally diverse triterpenoids and diterpenoids from two endangered Pinaceae plants endemic to the Chinese Qinling Mountains and their bioactivities.

A joint phytochemical investigation on the MeOH extracts of the twigs and needles of two endangered Pinaceae plants endemic to the Chinese Qinling Mountains, Picea neoveitchii (an evergreen spruce) and Larix potaninii var. chinensis (a deciduous larch), led to the isolation and characterization of 34 and 24 structurally diverse terpenoids, respectively. Among them, seven are previously undescribed, including a picane-type [i.e., 14(13 â†’ 12)abeo-12αH-serratane] (neoveitchin A) and a serratane-type (neoveitchin B) triterpenoids, and an abietane-type (neoveitchin C) as well as four labdane-type (potalarxins A-D) diterpenoids. Their structures and absolute configurations were established by extensive spectroscopic methods and/or X-ray diffraction analyses. All isolates were evaluated for their inhibitory activities against the human protein tyrosine phosphatase 1B (PTP1B). Serrat-14-en-3α,21ß-diol, betulinic acid, 3ß-hydroxy-11-ursen-13(28)-olide, ursolic acid, and oleanolic acid were found to have considerable inhibitory effects against PTP1B, with IC50 values ranging from 1.1 to 18.1 µM. The interactions of the bioactive triterpenoids with PTP1B were thereafter performed by employing molecular docking studies. In addition, 7-oxo-dehydroabietic acid (an abietane-type diterpenoid) and mangiferonic acid (a cycloartane-type triterpenoid) inhibited acetyl-coenzyme A carboxylase 1 (ACC1), with IC50 values of 3.4 and 6.6 µM, respectively.

Liriogerphines A-D, a Class of Sesquiterpene-Alkaloid Hybrids from the Rare Chinese Tulip Tree Plant.

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.

Structurally diverse glycosides of secoiridoid, bisiridoid, and triterpene-bisiridoid conjugates from the flower buds of two Caprifoliaceae plants and their ATP-citrate lyase inhibitory activities.

The ethanolic extracts of the dried flower buds of two Caprifoliaceae plants, Lonicera japonica and Abelia × grandiflora, showed considerable inhibitory activities against adenosine triphosphate (ATP)-citrate lyase (ACL), a new promising drug target for the treatment of metabolic disorders. Bioassay-guided purification in conjunction with HPLC-PDA profiling led to the isolation and characterization of thirty-five (1-35) and fourteen (1'-14') structurally diverse compounds from the above two plant extracts, respectively. Compounds 1-9 and 1'-6' are previously undescribed glycosides. Their structures were elucidated on the basis of spectroscopic data, electronic circular dichroism (ECD), and single crystal X-ray diffraction analyses. In particular, lonicejaposide A (1) has an unprecedented skeleton generated through the coupling of C-7 in secologanin with C-2'' in phenylacetaldehyde via an aldol condensation. Abeliflorosides A (1') and B (2') are hitherto unknown glycosides of triterpene and bisiridoid conjugates constructed through the formation of a 1,3-dioxane moiety. All the isolates were evaluated for their inhibitory activities against ACL. Compounds 9, 25-28, 31, 1', 2', and 14' displayed significant inhibitory effects, with IC50 values ranging from 0.1 to 14.2 µM. The interactions of selected compounds possessing different structure features (e.g., 9, 25, 31, and 2') with ACL were thereafter performed by employing molecular docking studies. In addition, compound 2', the most complex triterpene-bisiridoid conjugate glycoside reported herein, also inhibited acetyl-CoA carboxylase 1 (ACC1), with an IC50 value of 7.9 µM. The dried material of the flower buds of L. japonica (honeysuckle) is a well-known traditional oriental medicine (i.e., Flos Lonicerae Japonicae, FLJ) and has long been used in large quantities. The above findings not only provide new insights for the development of multipurpose utilization of FLJ in healthcare community, but also provide profitable clues indicating that the flower buds of A. × grandiflora might be a potential alternative to FLJ in the traditional Chinese medicine market.

A new coumarin derivative from the stems of the endangered plant Ulmus elongata.

A preliminary phytochemical investigation of the stems of the endangered plant Ulmus elongata led to the isolation of a new coumarin derivative (named ulmuselactone A, 1) and eight known compounds (2-9). The new structure was elucidated by detailed analysis of comprehensive spectroscopic methods, and its absolute configuration was established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. The isolated compounds were evaluated for their antibacterial activities.

Stewartiacids A-N, C-23 carboxylated triterpenoids from Chinese Stewartia and their inhibitory effects against ATP-citrate lyase and NF-κB.

Fourteen previously undescribed naturally occurring C-23 carboxylated triterpenoids, stewartiacids A-N (1-14), were isolated and characterized from the twigs and leaves of the ornamental and medicinal plant Stewartia sinensis (Chinese Stewartia), a 'vulnerable' species endemic to China. The new structures were elucidated on the basis of spectroscopic data, single crystal X-ray diffraction, and electronic circular dichroism (ECD) analyses. Stewartiacids A (1) and B (2) are isoursenol derivatives. Stewartiacid C (3) is a 12-oxo-γ-amyrin analogue. Both isoursenol and γ-amyrin derivatives are quite rare in nature. Stewartiacids D (4) and E (5) are 13,27-cycloursane-type compounds. Stewartiacids K (11) and L (12) are ursane-type triterpene and phenylpropanol adducts built through a 1,4-dioxane ring, which are also seldom reported in the literature. The rest are common C-23 carboxylated ursane-type (6-10) and oleanane-type (13, 14) pentacyclic triterpenoids. Stewartiacids G (7), K (11), and L (12) showed moderate inhibitory effects against ATP-citrate lyase (ACL), with IC50 values of 12.5, 2.8, and 10.6 µM, respectively. Stewartiacid K (11) also exhibited moderate inhibition (IC50: 16.8 µM) of NF-κB.

Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities.

Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha.

[Contents of secondary metabolites and anti-bacterial activity of compound Caulis Sargentodoxae decoction].

OBJECTIVE: To compare the contents of secondary metabolites and the anti-bacterial activity of seven different compound Caulis Sargentodoxae decoctions. METHODS: Kirby-Bauer disk agar diffusion method was used for measuring anti-bacterial activity. The contents of secondary metabolites were determined by spectrometry. The correlation and path analysis were used to identify the goal compound. RESULT: The secondary metabolites contents and anti-bacterial activity of seven different compound Caulis Sargentodoxae decoctions varied significantly. The total contents of six secondary metabolites of Shushao Caulis Sargentodoxae decoction was the highest, while that of Caihu Caulis Sargentodoxae decoction was the second highest and that of Yiyi Caulis Sargentodoxae decoction was the lowest. The anti-bacterial activity of Shushao Caulis Sargentodoxae decoction was the highest and that of Cangbai Caulis Sargentodoxae decoction was the lowest. The correlation and path analysis showed that the total tannin and total chlorogenic acid might be the major factors related to the anti-bacterial activity of compound Caulis Sargentodoxae decoctions. CONCLUSION: The total contents of six secondary metabolites and the anti-bacterial activity of Shushao Caulis Sargentodoxae decoction are the highest among seven different decoctions and there is a significant correlation of the anti-bacterial activity with the contents of total tannin and total chlorogenic acid.

[Correlation of anti-bacterial activity with secondary metabolites content in Sargentodoxa Cuneata tables].

OBJECTIVE: To explore the correlation between the content of the secondary metabolites and the anti-bacterial activity of Sargentodoxa cuneata tables. METHODS: The content of secondary metabolies was determined by spectrometers. Staphylococcus aureus and Bacillus subtilis were used as the experimental strains. The minimal inhibition concentration (MIC) was calculated using agar plate dilution method on Kirby-Bauer disk. The minimal bacterialcidal concentration (MBC) was calculated using tube dilution method. Two-way analysis and Turkey's test was employed in the statistical analysis. RESULT: The anti-bacterial activities on Staphylococcus aureus and Bacillus subtilis of the first batch of S. cuneata tables produced in Anhui was the highest [the diameter of anti-bacterial zone, MIC, MBC was (9.67 +/-0.29) mm, 12.5 mg/ml, 31.25 mg/ml and (10.17 +/-0.58) mm, 12.5 mg/ml, 31.25 mg/ml, respectively]. Those of the second batch of S. cuneata tables produced in Jiangsu was the lowest [the diameter of anti-bacterial zone, MIC, MBC was (7.67 +/-0.29)mm, 25 mg/ml, 125 mg/ml and (8.17 +/-0.29)mm, 25 mg/ml, 125 mg/ml, respectively]. There was significant difference in the antibacterial activity on Staphylococcus aureus between different producing areas of S. cuneata tables and batches (P<0.01), while there was also significant difference in the antibacterial activity on Bacillus subtilis between different producing areas (P<0.01) and no significant difference between different batches (P>0.05). The contents of 6 secondary metabolites of S. cuneata tables produced in different areas and in different batches were different. The total content of 6 secondary metabolites of the first batch of S. cuneata tables produced in Anhui was the highest with mean 3.61%. Those of the second batch produced in Jiangsu were the lowest with mean 1.90 %. There was significant difference in the content of total alkaloid and dissociated emodin between different producing areas (P<0.01) and no difference between different batches (P>0.05). For the content of total chlorogenic acid, flavonoids, total tannin and total saponin, there was significant difference between different producing areas and batches (P<0.01). The correlation analysis showed that the main secondary metabolites influencing the anti-bacterial activity were total saponin, total tannin, dissociated emodin and total chlorogenic acid. CONCLUSION: There is difference among the content of the secondary metabolites and anti-bacterial activity of S. cuneata tables produced in different areas and different batches. There is significant correlation of the anti-bacterial activity with the content of total saponin, total tannin, dissociated emodin and total chlorogenic acid in S. cuneata tables.