New Cadinane Sesquiterpenes from the Stems of Kadsura heteroclita

New Dibenzocyclooctadiene Lignans and Phenolics from Kadsura heteroclite with Anti-Inflammatory Activity

A chemical investigation of K. heteroclite led to isolation of two new dibenzocyclooctadienes (1 and 2) together with 14 known compounds (3-16) by using multiple chromatographic techniques. New compounds (1 and 2) were obtained and identified by spectroscopic methods (HR-ESI-MS, 1D and 2D NMR, and ECD) as well as by comparison of their experimental data with those reported in the literatures. All the isolates were evaluated for their ability to modulate TNF-α production in lipopolysaccharide (LPS) stimulated RAW264.7 cells. Among them, compound 5 displayed the most inhibition against tumor necrosis factor (TNF)-α production with IC50 value of 6.16±0.14 μM. Whereas, compounds (1, 3, and 6) showed the significant inhibition (IC50 values ranging from 9.41 to 14.54 μM), and compounds (2, 4, 9, 10, 13, 15, and 16) exhibited moderate inhibition (IC50 values ranging from 19.27 to 40.64 μM) toward TNF-α production, respectively.

Anti-RAFLS Triterpenoids and Hepatoprotective Lignans From the Leaves of Tujia Ethnomedicine Kadsura heteroclita (Xuetong)

A pair of 3,4-seco-cycloartane triterpenoid isomers with a rare peroxy bridge, namely, xuetonins A and B (1 and 2), four new lignans xuetonlignans A-D (3-6), a new sesquiterpene xuetonpene (7), and a new natural product xuetonin C (8), along with 43 known compounds, were obtained from the leaves of Tujia ethnomedicine, Kadsura heteroclita. Their structures and configurations were determined with the help of a combination of 1D- and 2D-NMR, HRESIMS spectra, electronic circular dichroism (ECD), and X-ray diffraction data. Compounds 2, 10, 13-15, and 17-19 showed moderate-to-potent activity against rheumatoid arthritis fibroblast-like synoviocytes (RAFLS) with IC50 values of 19.81 ± 0.26, 12.73 ± 0.29, 5.70 ± 0.24, 9.25 ± 0.79, 5.66 ± 0.52, 11.91 ± 0.44, 13.22 ± 0.27, and 15.94 ± 0.36 μM, respectively. Furthermore, compounds 22, 25, and 31 exhibited significant hepatoprotective effects against N-acetyl-p-aminophenol (APAP)-induced toxicity in HepG2 cells at 10 μM, and the cell viability increased by 12.93, 25.23, and 13.91%, respectively, compared with that in the model group (cf. bicyclol, 12.60%).

Chemical Constituents of the Roots of Schisandra chinensis

One new phenylpropanoid schineolignin D (1), one new sesquiterpene (-)-(7S,10S)-3,11,12,13-tetrahydroxycalamenene (2), one new quinic acid 4-(E)-O-coumaroylquinic acid ethyl ester (3), and seven known compounds 4-10 were separated from the roots of Schisandra chinensis. The chemical structures of all compounds were characterized by NMR spectroscopic experiments. All compounds were assessed for their neuroprotective effects on PC12 cell lines induced by H₂ O₂ . Compounds 1, 3-4, and 7 showed statistically significant neuroprotective activities with the negative control group at 12.5 μM.

Sesquiterpenes from Kadsura coccinea attenuate rheumatoid arthritis-related inflammation by inhibiting the NF-κB and JAK2/STAT3 signal pathways

The roots of Kadsura coccinea is commonly used in Tujia ethnomedicine, named "heilaohu", having the effect of treating rheumatic arthritis (RA). Chemical investigation on the ethanol extract of heilaohu led to the isolation of one undescribed cuparane sesquiterpenoid, heilaohusesquiterpenoid A, one undescribed carotane sesquiterpenoids, heilaohusesquiterpenoid B, and eighteen sesquiterpene derivatives. Their structures were subsequently determined based on their 1D and 2D-NMR, HR-ESI-MS, and ECD spectroscopic data. Gaultheriadiolide was the most cytotoxic compound against the proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells with an IC₅₀ value of 9.37 μM. In the same line, nine compounds exhibited significant inhibition effects against TNF-α and IL-6 release in the LPS-induced RAW264.7 cells with IC₅₀ values ranging between 1.03 and 10.99 μM. The potential molecular mechanisms of the active compounds against RA were established through pharmacological network analysis based on the initial screening results. Experimental validation showed that gaultheriadiolide suppressed inflammation by inhibiting the NF-kB and JAK2/STAT3 pathways. This study enriches the structural diversity of sesquiterpenes in K. coccinea and lays a foundation for further anti-RA and anti-inflammatory studies.

Triterpenoids From Kadsura coccinea With Their Anti-inflammatory and Inhibited Proliferation of Rheumatoid Arthritis-Fibroblastoid Synovial Cells Activities

One new 3,4-seco-17,13-friedo-lanostane triterpenoid heilaohuacid A (1), one new 3,4-seco-17,14-friedo-lanostane triterpenoid heilaohuacid B (2), five new 3,4-seco-lanostane triterpenoids heilaohuacids C-D (3–4) and heilaohumethylesters A-C (7–9), one new 3,4-seco-cycloartane triterpenoid heilaohuacid E (5), and one new intact-lanostane triterpenoid heilaohuacid F (6), together with twenty-two known analogues (10–31), were isolated from heilaohu. Their structures were determined using HR-ESI-MS data, 1D and 2D NMR spectra, ¹³C NMR calculations, and electronic circular dichroism (ECD) calculations. Heilaohuacids A and B (1 and 2) contain a 3,4-seco ring A and unprecedented migration of Me-18 from C-13 to C-17 or C-14 to C-18. This type of lanostane triterpenoid derivatives was rarely reported so far. More importantly, all compounds against inflammatory cytokines IL-6 and TNF-α levels on LPS-induced RAW 264.7 macrophages were evaluated, and compounds 4 and 31 significantly inhibited the release level of IL-6 with IC₅₀ values of 8.15 and 9.86 μM, respectively. Meanwhile, compounds 17, 18, and 31 significantly inhibited proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells in vitro with IC₅₀ values of 7.52, 8.85, and 7.97 μM, respectively.

Heilaohuguosus A-S from the fruits of Kadsura coccinea and their hepatoprotective activity

Phytochemical investigations on the fresh fruits of Kadsura coccinea (Lem.) A. C. Sm. have led to the isolation of fourteen undescribed 2,2'-cyclolignans named heilaohuguosus A-N, four undescribed aryltetrahydronaphthalene lignans, heilaohuguosus O-R and one tetrahydrofuran lignan, heilaohuguosu S, with twenty-seven previously described lignan analogues. Their structures and absolute configurations of heilaohuguosus A-S were established by spectroscopic methods including 1D and 2D-NMR techniques and CD experiments. All isolated compounds were evaluated for their hepatoprotective activity against APAP-induced toxicity in HepG-2 cells, four 2,2'-cyclolignans, heilaohuguosus A and L, tiegusanin I and kadsuphilol I showed good hepatoprotective activities against APAP toxicity in HepG-2 cells with cell survival rates of 53.5 ± 1.7%, 55.2 ± 1.2%, 52.5 ± 2.4%, and 54.0 ± 2.2% (positive control bicyclol, 52.1 ± 1.3%) at 10 μM, respectively.

A review of the phytochemistry and pharmacology of Kadsura heteroclita, an important plant in Tujia ethnomedicine

ETHNOPHARMACOLOGICAL RELEVANCE

Kadsura heteroclita (Roxb.) Craib (traditionally known as "Xue Tong") is an important member of the economically and medicinally important plant family Schisandraceae. "Xue Tong" is an imperative ingredient of the Tujia ethnomedicine, traditionally used for the treatment of rheumatoid arthritis (RA), hepatitis, and muscles and joint spasm. The plant is known to be a rich source of lignans and triterpenoids. These classes of natural products have been known to possess various pharmacological activities.

AIM OF REVIEW

This review was motivated by the importance of K. heteroclita in traditional Chinese medicine (TCM). It aims to compile the available information on its botanical distribution and description, traditional uses, phytochemistry, pharmacological activities, toxicity, and quality control to provide a solid base for further research and development.

MATERIALS AND METHODS

Relevant literature was collected by several scientific databases including PubMed, CNKI, Scifinder, The Plant List, Google Scholar, Baidu Scholar, Books (Tujia pharmaceutical records, Guangxi Chinese herbal medicine, Hunan pharmaceutical records and Field identification manual of Chinese herbal medicine) and other literature sources (Flora of China, Pharmacopoeia of the People's Republic of China) which helped in collecting maximum data about the studied species.

RESULTS

Traditional uses of K. heteroclita have proven its medicinal importance, providing a rationale for scientific research. Phytochemical studies on the stem of K. heteroclita resulted in the identification of 187 chemical constituents, among which lignans and triterpenoids are the predominant groups. The isolates and crude extracts have been found to exhibit a wide spectrum of in vivo and in vitro pharmacological activities such as anti-RA, anti-inflammatory and analgesic, hepatoprotection, anti-HIV, anti-cancer and anti-HBV. Schisanlactone E (xuetongsu), a triterpenoid, is one of the major components of K. heteroclita exhibiting anti-cancer, neuroprotective and anti-neuroinflammation activities. Interestingly and luckily, this plant has been found to be safe and non-toxic within the therapeutic dose range.

CONCLUSION

Pharmacological investigations have validated the use of K. heteroclita in traditional Chinese medicine (TCM). Literature review has demonstrated that lignans and triterpenoids are possibly responsible for most of the biological activities exhibited by this plant. To conclude, this plant shows immense potential for the discovery of more potent bioactive secondary metabolites and therefore further phytochemical and biological studies on other parts of K. heteroclita need to be conducted and more compounds need to be tested regarding their biological activities to completely explore its value as a tremendously important medicinal plant species.

Kadsura heteroclita stem ethanol extract protects against carbon tetrachloride-induced liver injury in mice via suppression of oxidative stress, inflammation, and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Kadsura heteroclita stem (KHS) is a well-known hepatoprotective Tujia ethnomedicine (folk named Xuetong), has long been used for the prevention and treatment of hepatitis and liver diseases.

AIM OF THE STUDY

To explore the protective effects of KHS against carbon tetrachloride (CCl4)-induced liver injury and the underlying mechanism, particularly antioxidative, anti-inflammatory, and anti-apoptotic potentials.

MATERIALS AND METHODS

The acute toxicity of KHS was measured by the method of maximum tolerated dose (MTD). Liver injury in mice was induced by intraperitoneal injection of 25% carbon tetrachloride (olive oil solubilization) 2 times every week. After modeling, mice in KHS groups were treated with KHS at 100, 200, 400 mg/kg/d, mice in positive control group were treated with bifendate (30 mg/kg/d), and mice in normal and model groups were given ultrapure water. After 4 weeks of treatment, blood of mice was taken from the orbital venous plexus before mice euthanized, the liver, spleen, and thymus of mice were weighed by dissecting the abdominal cavity after mice euthanized. Moreover, the liver of mice was selected for histological examination. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in mice serum were measured using the automatic biochemical analyzer. The levels of superoxide dismutase (SOD), myeloperoxidase (MPO), malondialdehyde (MDA), glutathione peroxidase (GPX-2), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), Bcl-2-associated X (Bax), B-cell lymphoma-2 (Bcl-2), Caspase-3, and Caspase-8 in mice liver were measured by Elisa kits. Furthermore, the protein expression of Bcl-2 and Bax in mice liver tissue was detected by Western blot.

RESULTS

The MTD of KHS was determined to be 26 g/kg in both sexes of mice. Treatment with KHS dose-dependently protected the liver and other main organs against CCl4-induced liver injury in mice. The ALT and AST levels in mice liver were significantly reduced after treatment with KHS at the dose of 100, 200, and 400 mg/kg. In addition, the liver histopathological analyses revealed that KHS markedly alleviated inflammatory cell infiltration, hepatic fibrosis, hepatocyte ballooning, necrosis and severe apoptosis of hepatocytes induced by CCl4. Further assay indicated that KHS significantly suppressed the production of MDA and MPO, while markedly increased the level of SOD and GPx-2. The TNF-α and IL-6 level in mice liver tissue were decreased by KHS, whereas the IL-10 level was increased. KHS also inhibited hepatocyte apoptosis by significantly reducing the expression of Bax, Caspase-3, Caspase-8, as well as increasing the expression of Bcl-2. Besides, the Western blot results strongly demonstrated that KHS inhibited hepatocyte apoptosis, as evidenced by reducing the expression of Bax protein and increasing the expression of Bcl-2 protein in liver injury tissues.

CONCLUSIONS

This research firstly clarified that KHS has a significant protective effect against CCl4-induced liver injury, which might be closely related to alleviating oxidative stress, reducing inflammatory response, and inhibiting hepatocyte apoptosis.

Xuetonglactones A-F: Highly Oxidized Lanostane and Cycloartane Triterpenoids From Kadsura heteroclita Roxb. Craib

Xuetonglactones A–F (1–6), six unreported highly oxidized lanostane- and cycloartane-type triterpenoids along with 22 known scaffolds (7–28) were isolated from the stems of Kadsura heteroclita (Roxb.) Craib. Compared with previous congeners, xuetonglactone A (1), possesses an unprecedented 20,21-α-epoxide, and xuetonglactone D (4) features an unusual 19-α-hydroperoxyl moiety. The structures and the absolute configurations of the compounds were established by extensive one- and two-dimensional NMR, and electronic circular dichroism (ECD) spectroscopic analysis, with those of 1 and 5 confirmed by single-crystal X-ray diffraction technique. Compounds 1 and 2 exhibited inhibition of iNOS activity in LPS-induced macrophages with IC₅₀ values of 22.0, and 17.0 μg/mL, respectively. While compounds 6, 7, 8, and 24 showed potent cytotoxic activities against human cervical cancer cell lines (HeLa) with the IC₅₀ values of 4.0, 5.8, 5.0, and 6.4 μM, and against human gastric cancer cells (BGC 823) with the IC₅₀ values of 2.0, 5.0, 2.5, and 2.0 μM, respectively. Moreover, plausible biogenetic pathways of (1–6) were also proposed.

Schinortriterpenoids from Tujia ethnomedicine Xuetong-The stems of Kadsura heteroclita

In the present work, we take advantage of the characteristic NMR signal (δ_C-10 = 96.0-99.9) for guiding the isolation of schinortriterpenoids (SNTs) from n-butanol fraction of stems of Kadsura heteroclita which is a Tujia ethnomedicine with trivial name "Xuetong". This effort resulted in the identification of three unreported 3,4:9,10-disecocycloartane triterpenoids xuetongdilactones A-C and three undescribed SNTs xuetongdilactones D-F, along with two known SNTs, namely, wuweizidilactone B and micrandilactone B. The structures of the unreported compounds were established based on 1D, and 2D NMR, HRESIMS, and ECD spectroscopic data analysis. The absolute stereochemistry of xuetongdilactone A was determined by X-ray diffraction analysis along with ECD calculation. The antioxidant and cytotoxic activities were evaluated for all the isolated compounds.

Two New AChE Inhibitors Isolated from Li Folk Herb Heilaohu "Kadsura coccinea" Stems

Two new triterpenoids, named kadsuricoccins A and B, together with three known ones, were isolated from the Li folk herb Heilaohu, the stems of Kadsura coccinea (Lem.) A. C. Smith, which was used for food and as a healthy supplement. Their structures were elucidated by comprehensive analyses of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic data. To search healthy components, an acetylcholinesterase (AChE) inhibitory activity test by Ellman’s Method was conducted, kadsuricoccins A and B showed activity with the AChE inhibit index (AII) up to 68.96% ± 0.19% and 57.8% ± 0.11% at 94 nM (compared with positive control tacrine AII 79.80% ± 0.20%, 9.4 nM), respectively.

Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products

Sesquiterpene synthases in Trichoderma viride have been seldom studied, despite the efficiency of filamentous fungi for terpenoid production. Using the farnesyl diphosphate-overexpressing Saccharomyces cerevisiae platform to produce diverse terpenoids, we herein identified an unknown sesquiterpene synthase from T. viride by genome mining and determined the structure of its corresponding products. One new 5/6 bicyclic sesquiterpene and its esterified derivative were characterised by GC–MS and 1D and 2D NMR spectroscopy. To the best of our knowledge, this is the first well-identified sesquiterpene synthase from T. viride to date.