Three novel constituents from curculigo capitulata and revision of C-2 stereochemistry in nyasicoside

Combination of Molecular Networking and LC-MS/MS Profiling in Investigating the Interrelationships between the Antioxidant and Antimicrobial Properties of Curculigo latifolia

Curculigo is a potent plant with a variety of traditional uses, such as anti-oxidant, anti-diabetic, anti-tumor, anti-bacterial, anti-cancer, anti-osteoporosis, and wound-healing. The comprehensive profiling of the Curculigolatifolia metabolome was carried out by generating a molecular network (MN) from Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) data to profile the methanol extract and correlating them with their antioxidant (2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), total phenolic contents (TPC), and β-carotene) and antimicrobial (disk-diffusion agar method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC)) properties. The antioxidant capacity was observed to be significantly higher in the rhizome crude extract, with 18.10 ± 0.91 µg/mL DPPH activity, and a β-carotene bleaching result of 35.20%. For the antimicrobial activity, the leaf crude extract exhibited a strong Staphylococcus aureus and Salmonella choleraesuis (8-15 ± 3.0 mm) inhibition in the disk-diffusion agar. The leaf extract also exhibited maximum antibacterial activity against S. aureus (MIC = ±0.25 mg/mL, MBC = ±0.25 mg/mL) and S. choleraesuis (MIC = ±0.25 mg/mL, MBC = ±0.25 mg/mL). LC-MS/MS analysis and MN revealed norlignans and phenolic glycosides as major metabolites in the rhizome and leaf extracts of the negative mode (M - H)^-. Fourteen known compounds were identified, and three unknown compounds were putatively identified in the rhizome extract, while ten known compounds and six unknown compounds were putatively identified in the leaf extract.

Amomutsaokols A-K, diarylheptanoids from Amomum tsao-ko and their α-glucosidase inhibitory activity

Eleven undescribed diarylheptanoids, amomutsaokols A‒K (1-11), together with 13 known ones (13-24), were isolated from the active fraction of the fruits of Amomum tsao-ko. The structures of the undescribed compounds were determined by extensive 1D and 2D NMR, HRESIMS and ECD calculations. Compounds 3-5, 7, 8, 12, 14 and 19 showed obviously α-glucosidase inhibitory activity with IC₅₀ values ranging from 12.9 to 48.8 μM. An enzyme kinetic analysis indicated that compounds 8 and 9 were α-glucosidase noncompetitive inhibitors with K_i values of 18.5 and 213.0 μM, respectively. This study supported diarylheptanoids as the active constituents of A. tsao-ko with α-glucosidase inhibitory effects.

Norlignan glucosides from Hypoxis hemerocallidea and their potential in vitro anti-inflammatory activity via inhibition of iNOS and NF-κB

Eleven diarylpentanoid/norlignan glucosides, along with five other specialized metabolites, were isolated and characterized from the hydro-alcoholic extract of Hypoxis hemerocallidea corms. Hypoxhemerolosides A-F were found to be undescribed compounds. Curcapicycloside was isolated and identified for the first time in its original form, previously it was reported as a methylated derivative. In addition, (1S,2R)-1-(3,4-dihydroxyphenyl)-5-(4-β-D-glucopyranoxy-3-hydroxyphenyl)-1-methoxypent-4-yn-2-ol and (1S,2R)-1-(3,4-dihydroxyphenyl)-1-ethoxy-5-(4-β-D-glucopyranoxy-3-hydroxyphenyl)pent-4-yn-2-ol were isolated and characterized as artifacts, generated during extraction/isolation procedures from possible 1-(3,4-dihydroxyphenyl)-5-(4-β-D-glucopyranoxy-3-hydroxyphenyl)pent-4-yne-1,2-diol. Structure elucidation was mainly achieved by the interpretation of 1D and 2D NMR and HRESIMS data. The isolated compounds were screened for anti-inflammatory activity in terms of iNOS and NF-κB inhibition as well as for cytotoxicity. Hypoxhemerolosides C-E and obtuside A moderately inhibited nitric oxide production in LPS-stimulated mouse macrophages (RAW 264.7).

Structural Elucidation and Total Synthesis of Three 9-Norlignans from Curculigo capitulata

Capitulactones A-C, three unprecedented 9-norlignans featuring a unique 3,5-dihydrofuro[2,3- d]oxepin-7(2 H)-one scaffold, were isolated from the roots of Curculigo capitulata. Their structures with absolute configurations were unambiguously established by a combination of spectroscopic data, ECD analysis, and total synthesis. Biomimetic total syntheses of three pairs of the corresponding enantiomers were achieved in 9-10 steps with overall yields of 14.8, 12.7, and 10.3%, respectively. Notably, the unique scaffold of the common western hemisphere of the molecules was constructed by using the oxidation-reduction strategy from benzodihydrofuran.

Tetrahydropyran- and tetrahydrofuran-containing diarylheptanoids from Hedychium coronarium rhizomes

Seven new diarylheptanoids (1-7) were isolated from the n-BuOH-soluble fraction of the rhizome of Hedychium coronarium. Hedycoropyrans A-C (1-3) contain a tetrahydropyran moiety, while hedycorofurans A-D (4-7) contain a tetrahydrofuran moiety, belonging to a rare structural class of diarylheptanoids. Their structures including stereochemistry were elucidated on the basis of 1D and 2D NMR and ECD spectroscopic analyses and HRESIMS data of the parent compounds and the isopropylidene derivatives of 4 and 7.

Pd-catalyzed decarboxylative allylic coupling of acetates of Baylis–Hillman alcohols with propiolic acids: a highly regio- and stereoselective synthesis of 1,5-diarylpent-1-en-4-yne derivatives

Pd-catalyzed decarboxylative allylic coupling of acetates of Baylis–Hillman alcohols with alkynyl carboxylic acids leading to the formation of 1,5-diarylpent-1-en-4-ynes in a highly regio- and stereoselective manner has been developed.

Medicinal plants of genus Curculigo: traditional uses and a phytochemical and ethnopharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

In the genus Curculigo, Curculigo orchioides Gaertn, Curculigo capitulata (Lour) O. Ktze and Curculigo pilosa (Schumach. & Thonn.) Engl are often used in traditional medicine. Curculigo orchioides is used for the treatment of impotence, limb limpness, arthritis of the lumbar and knee joints, and watery diarrhea in traditional Chinese medicine, and also used as a potent immunomodulator and aphrodisiac in the Ayurvedic medical system. Curculigo capitulata is used for the treatment of consumptive cough, kidney asthenia, impotence and spermatorrhea, hemorrhoids, asthma, jaundice, diarrhea, colic and gonorrhea in traditional Chinese and India medicine, and to treat urinary tract infection, acute renal pelvis and nephritis, nephritis-edema, cystitis, nephrolithiasis, hypertension and rheumatic arthritis in traditional Dai medicine. Curculigo pilosa are applied to treat gastrointestinal and heart diseases in Africa.

AIM OF THE REVIEW

This review aims to exhibit up-to-date and comprehensive information about traditional uses, phytochemistry, pharmacology and toxicology of medicinal plants in the genus Curculigo, and has an insight into the opportunities for the future research and development of Curculigo plant.

METHODS

A bibliographic investigation was performed by analyzing the information available on Curculigo plant from worldwide accepted scientific databases (Pubmed, Scopus and Web of Science, SciFinder, Google Scholar, Yahoo). Furthermore, information also was obtained from some local and foreign books on ethnobotany and ethnomedicines.

RESULTS

Curculigo orchioides, Curculigo capitulata and Curculigo pilosa have been used as traditional medicine to treat kinds of diseases such as impotence, limb limpness, gastrointestinal and heart diseases, etc. Phytochemical investigation of eight species of the genus Curculigo has resulted in identification of more than 110 compounds. The content of curculigoside is used as an indicator to evaluate the quality of rhizome of Curculigo orchioides. The medicinal plants have showed a wide spectrum pharmacological activities, including adaptive, immunostimulatory, taste-modifying and sweet-tasting, antioxidant, mast cell stabilization, antihistaminic and antiasthmatic, hepatoprotective and neuroprotective activity. Toxicological test indicated that Curculigo orchioides at the dose of 120 g/kg after administrating rats for 180 days may cause injury of liver and kidney.

CONCLUSION

The medicinal plants of genus Curculigo have emerged as a good source of the traditional medicines. Some uses of these plants in the traditional medicines have been validated by pharmacological investigation. However, the mechanism of their actions should be further elucidated; the particular constituent responsible for toxicity should be isolated and identified, and the target tissue and mechanism of toxic ingredients also deserve to be further investigated; more reference substances should be prepared, and sophisticated analytical technologies should be developed to comprehensively assess the quality of Curculigo herbs. These investigations will be helpful for further utilization of the plants of genus Curculigo.

Norlignan derivatives from Curculigo crassifolia and their DPPH radical scavenging activity

A novel norlignan derivative, crassifogenin C (1), and a known compound, curcapital (2), were isolated from the ethanolic extract of the rhizomes of Curculigo crassifolia. Their structures were elucidated on the basis of spectroscopic evidence and comparisons with literature data. Curcapital (2) was isolated from this plant for the first time. The free radical scavenging activity of the isolated compounds along with crassifoside E (3) and crassifoside F (4), which were reported previously, was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All compounds showed strong radical scavenging activity. The primary structure-activity relationship is also discussed.

New acetylenic norlignan compounds from rhizomes of Curculigo crassifolia

Two pairs of diastereoisomeric acetylenic norlignan compounds with PhCH(OR₁)CH(OR₂)CH₂C≡CPh skeleta: (1R, 2R)-1-O-methylnyasicoside (1) and (1S, 2R)-1-O-methylnyasicoside (2), and (1R, 2R)-crassifogenin D (3) and (1S, 2R)- crassifogenin D (4), were isolated from the ethanolic extract of rhizomes of Curculigo crassifolia. Compounds 3 and 4 are new and their structures were elucidated on the basis of spectroscopic evidence and comparisons with literature data.

Astonishing diversity of natural surfactants: 5. Biologically active glycosides of aromatic metabolites

This review article presents 342 aromatic glycosides, isolated from and identified in plants and microorganisms, that demonstrate different biological activities. They are of great interest, especially for the medicinal and/or pharmaceutical industries. These biologically active natural surfactants are good prospects for the future chemical preparation of compounds useful as antioxidant, anticancer, antimicrobial, and antibacterial agents. These glycosidic compounds have been classified into several groups, including simple aromatic compounds, stilbenes, phenylethanoids, phenylpropanoids, naphthalene derivatives, and anthracene derivatives.

Glucosides from Curculigo orchioides

From the rhizomes of Curculigo orchioides two phenolic glucosides named orchiosides A and B were isolated besides four known compounds and their structures were elucidated by the combination of 2D-NMR analysis, mass spectrometry and chemical evidences.

Isolation and structure determination of a novel furanic ester from the aerial part of Prasium majus

The aerial part of Prasium majus provided a new furanic ester, 2-2-[(5-formyl-6[(5-formylfuran-2-yl)methoxy] succinic acid dimethyl ester, (+/-)-hiziprafuran. Its structure was principally established by one- and two-dimensional NMR spectroscopy.

Benzylbenzoate and norlignan glucosides from Curculigo pilosa: structural analysis and in vitro vascular activity

From the rhizomes of Curculigo pilosa, two benzylbenzoate diglucosides, piloside A and piloside B, and a glucosyl-fused norlignan, pilosidine, previously obtained only as the tetra-O-methyl derivative, were isolated. Pilosidine showed facilitating effect on adrenaline evoked contractions in rabbit aorta isolated preparations.