Simultaneous high-performance liquid chromatography analysis of anthraquinones in sicklepod sprouts with α-glucosidase inhibitory activity.

INTRODUCTION: Sicklepod [Cassia obtusifolia L. syn Senna obtusifolia (L.) H.S. Irwin & Barneby, Fabaceae] sprouts are promising ingredients with health-promoting benefits. Notwithstanding, the pharmacologically active compounds in sicklepod sprouts have not been studied or analysed in detail. OBJECTIVE: This study aimed to isolate and structurally identify phytochemicals showing α-glucosidase inhibitory activity in sicklepod sprouts and simultaneously quantify the compounds in the sprouts to determine the optimal cultivation method and germination time to maximise active compounds. METHOD: A simultaneous high-performance liquid chromatography-ultraviolet (HPLC-UV) method with high sensitivity and accuracy was developed and used to analyse time-dependent changes in anthraquinone content during sicklepod germination. RESULTS: Thirteen anthraquinones were isolated and identified, of which six-chrysoobtusin, emodin, 1-O-methyl-2-methoxychrysophanol, 7-O-methylobtusin, chrysophanol, and physcion-showed moderate α-glucosidase inhibitory activity. The maximum content of anthraquinones in a sprout was observed on Day 5 under both light and dark conditions. CONCLUSION: The findings of this study revealed that sicklepod sprouts which are promising functional food materials contain a variety of anthraquinones.

Advanced quality assessment of Sanshishi (Gardenia jasminoides Ellis) and Kampo medicines using a monoclonal antibody against geniposide.

Gardenia jasminoides Ellis, a plant widely used in traditional medicine, is known for its array of biological activities. A key bioactive compound, geniposide (GE), an iridoid glycoside, significantly contributes to the medicinal properties of the plant, with potential side effects. Thus, a reliable and efficient method for GE detection is required to ensure the quality of medicinal-grade G. jasminoides Ellis. This study developed such a method by first synthesizing GE-bovine serum albumin conjugates to function as immunizing agents in mice. This led to the production of a monoclonal antibody (mAb 3A6) against GE from the fusion of splenocytes from immunized mice with myeloma cells (P3U1), resulting in a hybridoma that produces mAb 3A6. Thereafter, we developed a mAb 3A6-based indirect competitive enzyme-linked immunosorbent assay (icELISA). The icELISA exhibited satisfactory sensitivity (0.391-12.5 µg/ml) and repeatability (coefficients of variation <10%). The accuracy of this method was validated through a spike-recovery assay (recovery of 101-112%). Furthermore, the icELISA was employed to determine the GE content in plant and Kampo medicine samples. The GE content positively correlated with those determined by high-performance liquid chromatography-ultraviolet. The proposed icELISA is rapid, cost-effective, and reliable for high-throughput GE detection in G. jasminoides Ellis, thereby contributing to the improved quality control and standardization of this valuable medicinal plant.

Chemical Structures and Anti-proliferative Effects of Valeriana fauriei Constituents on Cancer Stem Cells.

We isolated the new sesquiterpenes, valerianaterpenes IV and V, and the new lignans valerianalignans I-III from the methanol extracts of the rhizomes and roots of Valeriana fauriei and elucidated their structures based on chemical and spectroscopic findings. The absolute configuration of valerianaterpene IV and valerianalignans I-III were established by comparing experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, valerianalignans I and II exerted anti-proliferative activity against human astrocytoma cells (U-251 MG) and their cancer stem cells (U-251 MG CSCs). Interestingly, valerianalignans I and II notably exerted anti-proliferative activities at lower concentrations against CSCs than non-CSCs, and the absolute configurations of these compounds affected their activities.

Quality assessment method for Chinpi, dried Citrus spp. peel and its derived Kampo medicines using specific monoclonal antibody against hesperidin.

INTRODUCTION: Hesperidin (hesperetin 7-rutinoside, HP), a flavonoid glycoside found in Citrus unshiu Marcowicz or Citrus reticulata Blanco (Rutaceae), has been reported to exert a variety of pharmacological effects. As the efficacies and qualities of their dried peel, Chinpi and its derived Kampo medicines can be evaluated by their HP contents, a method for HP detection must be developed. OBJECTIVES: To produce a specific monoclonal antibody against HP (mAb 5D12) to detect the HP contents in Japanese traditional medicines via indirect competitive enzyme-linked immunosorbent assay (icELISA). METHOD: BALB/c mice were immunised with many haptens of HP-bovine serum albumin (BSA) conjugates that were prepared using sodium periodate (NaIO4 ) to cause an immune response. In addition, conventional hybridoma techniques were utilised to generate mAb 5D12. RESULTS: The detection range of HP by the mAb 5D12-based icELISA was 1.56-25.0 ng/mL, with a detection limit of 1.12 ng/mL. The maximum coefficient of variation, as evaluated from the intra- and inter-assays, was <10.0%, and the percentages of recovery, as determined by the spike-recovery tests, were 105%-115%. Moreover, the HP content, which was obtained from the developed icELISA, correlated well with that obtained via high-performance liquid chromatography-ultraviolet (HPLC-UV). CONCLUSION: These validation analyses revealed that the established icELISA technique exhibited high precision and accuracy. Notably, this is the first report on the development of icELISA for the HP content-based quality control of Chinpi and its derived Kampo medicines.

Chemical structures and induction of cell death via heat shock protein inhibition of the prenylated phloroglucinol derivatives isolated from Hypericum erectum.

Four new prenylated phloroglucinol derivatives (+)-erectumol I (1a), (-)-erectumol I (1b), (-)-erectumol II (2a), and (+)-erectumol II (2b) were isolated from the methanol extracts of the whole plants of Hypericum erectum. These new compounds were isolated as a pair of enantiomers, respectively. The planar chemical structures and relative configurations of the new compounds were suggested by Cu-Kα X-ray diffraction analysis and been confirmed by high-resolution mass and 1D and 2D NMR spectroscopic data. The absolute configuration of the four new compounds were established by comparing the experimental and predicted electronic circular dichroism data. Isolated compounds 1b and 2b induced death of Adriamycin-treated HeLa cells. Their enantiomers 1a and 2a did not. In addition, the apparent mechanism of cell death of 1b was the inhibited expression of heat shock protein 105.

Construction of sulfur-containing compounds with anti-cancer stem cell activity using thioacrolein derived from garlic based on nature-inspired scaffolds.

Sulfur-containing compounds, such as cyclic compounds with a vinyl sulfane structure, exhibit a wide range of biological activities including anticancer activity. Therefore, the development of efficient strategies to synthesize such compounds is a remarkable achievement. We have developed a unique approach for the rapid and modular preparation of nature-inspired cyclic and acyclic sulfur-containing compounds using thioacrolein, a naturally occurring chemically unstable intermediate. We constructed thiopyranone derivatives through the regioselective sequential double Diels-Alder reaction of thioacrolein produced by allicin, a major component in garlic, and two molecules of silyl enol ether as the diene partner. The cytotoxicity toward cancer stem cells of the thiopyranones was equal to or higher than that of (Z)-ajoene (positive control) derived from garlic, and the thiopyranones had higher chemical stability than (Z)-ajoene.

Cell death-inducing activities via P-glycoprotein inhibition of the constituents isolated from fruits of Nandina domestica.

Two new pyrrole alkaloids methyl-E-mangolamide (1) and methyl-Z-mangolamide (2), four new megastigmane glycosides nandinamegastigmanes I-IV (3-6), and eight known compounds (7-14) were isolated from the methanol extract of the fruits of Nandina domestica. The structures of the new compounds were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of nandinamegastigmane I (3) was established upon comparing the experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, 1 and 2 showed cell death-inducing activity on the Adriamycin-treated HeLa cells. In addition, one of the mechanisms for cell death-inducing activity of 1 and 2 was suggested as inhibition of P-glycoprotein.

Cell death-inducing activities via Hsp inhibition of the sesquiterpenes isolated from Valeriana fauriei.

Three new sesquiterpenes, valerianaterpenes I-III, and eight known compounds have been isolated from the methanol extract of the rhizomes and roots of Valeriana fauriei. The chemical structures of the three new sesquiterpenes were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of valerianaterpene I was determined using X-ray crystallography. The cell death-inducing activity of isolated compounds alone or combination with Adriamycin (ADR) was observed by time-lapse cell imaging. Although the isolated compounds did not affect the number of mitotic entry cells and dead cells alone, kessyl glycol, kessyl glycol diacetate, and iso-teucladiol significantly increased the number of dead cells on ADR treated human cervical cancer cells. One of the mechanisms of cell death-inducing activity for the kessyl glycol acetate was suggested to be the inhibition of heat-shock protein 105 (Hsp105) expression level. This paper first deals with the naturally occurring compounds as Hsp105 inhibitor.

Linderapyrone: A Wnt signal inhibitor isolated from Lindera umbellata.

Linderapyrone, a Wnt signal inhibitor was isolated from the methanolic extract of the stems and twigs of Lindera umbellata together with epi-(-)-linderol A. Linderapyrone inhibited TCF/ß-catenin transcriptional activity that was evaluated using cell-based TOPFlash luciferase assay system. To evaluate the structure-activity relationship and mechanism, we synthesized linderapyrone and its derivatives from piperitone. As the results of further bioassay for synthesized compounds, we found both of pyrone and monoterpene moieties were necessary for inhibitory effect. cDNA microarray analysis in a linderapyrone derivative treated human colorectal cancer cells showed that this compound downregulates Wnt signaling pathway. Moreover, we successes to synthesize the derivative of linderapyrone that has stronger inhibitory effect than linderapyrone and ICG-001 (positive control).

Limonoids isolated from the Fortunella crassifolia and the Citrus junos with their cell death-inducing activity on Adriamycin-treated cancer cell.

From the fruits of Fortunella crassifolia and the peels of Citrus junos, two new limonoids, fortunellone and junosol were isolated together with three known compounds including nomilin. The chemical structures of the new compounds were elucidated based on chemical/physicochemical evidence. For fortunellone, the absolute configuration was established by comparison of experimental and predicted electronic circular dichroism (ECD) data. Fortunellon and nomilin significantly increased the number of dead cells on adriamycin (ADR)-treated human cervical cancer cells (HeLa). On the other hand, fortunellon and nomilin did not affects the number of dead cells alone. These results suggested that fortunellone and nomilin may have the potency as the chemotherapy enhancement agents.

Cytotoxic activities of sesquiterpenoids from the aerial parts of Petasites japonicus against cancer stem cells.

From the methanolic extract of the aerial parts of Petasites japonicus, six new eremophilane-type sesquiterpenoids, petasitesterpenes I-VI were isolated together with eight known compounds including S-japonin and eremophilenolide. The chemical structures of the isolated new compounds were elucidated based on chemical/physicochemical evidence. For petasitesterpenes I and II, the absolute configurations were established by comparison of experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, petasitesterpenes I, II, VI, and S-japonin showed cytotoxic activity against both human astrocytoma U-251MG cancer cells (non-CSCs) and their cancer stem cells (CSCs) isolated by sphere formation. In addition, cytotoxic activities of these compounds against breast cancer MDA-MB-231 were evaluated, supporting that petasitesterpene II has more effective than other isolated compounds.

Chemical structures and cytotoxic activities of the constituents isolated from Hibiscus tiliaceus.

Five new cadinene-type sesquiterpenes, hibiscusterpenes I-V (1-5), and six known compounds (6-11) have been isolated from the methanol extract of the stems and the twigs of Hibiscus tiliaceus. The structures of the new compounds were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of hibiscusterpene I (1) was determined using X-ray crystallography. For hibiscusterpene III (3), the absolute configuration was established upon comparison of the experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, hibiscone C (7) and syriacusin A (11) showed cytotoxic activity in HeLa cells. In addition, their cell death-inducing activity was observed using time-lapse cell imaging.

Structures of triterpenoids from the leaves of Lansium domesticum.

From the methanolic extract of the leaves of Lansium domesticum, three new onoceranoid-type triterpenoids, lansium acids X-XII and a new cycloartane-type triterpene, lansium acid XIII, were isolated. The chemical structures of the isolated new compounds were elucidated on the basis of chemical/physicochemical evidence. For new onoceranoid-type triterpenoids, the absolute configurations were established by comparison of experimental and predicted electronic circular dichroism (ECD) data. The isolated onoceranoid-type triterpenoids showed antimutagenic effects in the Ames assay against 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1).

Structures and Antimutagenic Effects of Onoceranoid-Type Triterpenoids from the Leaves of Lansium domesticum.

A methanol extract of the dried leaves of Lansium domesticum showed antimutagenic effects against 3-amino-1,4-dimethyl-5 H-pyrido[4,3- b]indole (Trp-P-1) and 2-amino-1-methyl-6-phenylimidazo[4,5- bI]pyridine (PhIP) using the Ames assay. Nine new onoceranoid-type triterpenoids, lansium acids I-IX (1-9), and nine known compounds (10-16) were isolated from the extract. The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence. The absolute stereostructures of the new compounds were determined via their electronic circular dichroism spectra. Several isolated onoceranoid-type triterpeneoids showed antimutagenic effects in an in vitro Ames assay. Moreover, oral intake of a major constituent, lansionic acid (10), showed antimutagenic effects against PhIP in an in vivo micronucleus test.

Chemical Structures of Novel Maillard Reaction Products under Hyperglycemic Conditions.

Two novel and two known compounds, 4-quinolylaldoxime and indole-3-aldehyde, were isolated from a reaction mixture consisting of D-glucose and L-tryptophan at physiological temperature and pH. The chemical structures of the two novel compounds were elucidated by spectroscopic analysis such as X-ray crystallography. One of the novel compound and the indole-3-aldehyde showed mutagenicity toward Salmonella typhimurium YG1024 with S9 mix. Furthermore, 4-quinolylaldoxime was detected from streptozotocin-induced diabetic rat plasma by LC-MS/MS analysis; however, the isolated compounds were not detected in rat diet extracts. To our knowledge, this is the first report in which 4-quinolylaldoxime was detected in rat plasma. These results suggest that amino-carbonyl reaction products may be formed in diabetic condition and induce genetic damage.

Structures of antimutagenic constituents in the peels of Citrus limon.

The methanolic extracts from the peels of Citrus limon were found to show antimutagenic effects against 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the Ames test. From the methanolic extracts, four new coumarins (wakayamalimonol A-D) and a new furanocoumarin (wakayamalimonol E) were isolated together with fifteen known compounds. The absolute stereostructures of the new compounds were determined by chemical synthesis and the modified Mosher's method. Among the isolated constituents, coumarins, furanocoumarins, and limonoids showed antimutagenic effects in the Ames test. One of the major constituent, limonin, showed significant antimutagenic effects against mitomycinC and PhIP in the micronucleus test in vivo.