Two new C13-norisoprenoids from Solanum lyratum

Structurally diverse lignans from Solanum lyratum: chemical evidence for their acetylcholinease inhibitory activity

A chemical investigation of Solanum lyratum Thumb. (Solanace) afforded two new lignans (1b and 3) and eleven known lignan analogues (1a, 2a/2b and 4-11). Compounds 1a/1b and 2a/2b were separated as two pairs of enantiomers by chiral high-performance liquid chromatography (HPLC). Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. The absolute configurations of compounds 1a/1b and 2a/2b were determined by comparing the experimental ECD data with the calculated values. All compounds were evaluated for their acetylcholinesterase (AChE) inhibitory activity. Notably, compared to the positive control, compounds 4 and 9 showed obvious AChE inhibition with their IC50 values of 1.30 ± 0.25 and 0.89 ± 0.04 μM, respectively. In addition, the possible interaction between acetylcholinesterase and the active compounds was also investigated by molecular docking.

Research progress on chemical components and pharmacological action of Solanum lyratum Thunb

OBJECTIVES

Solanum lyratum Thunb (SLT) is a perennial plant of the Solanaceae family, and is extensively used in the clinical practice of traditional Chinese medicine. Malaria, oedema, gonorrhoea, cancer, wind and fever, jaundiced hepatitis, cholecystitis and rheumatoid arthritis are among the diseases that it is used to treat. To offer a foundation for further development and usage of SLT, the pieces of literature about the chemical composition and pharmacological action of SLT were reviewed and analysed.

KEY FINDINGS

The chemical constituents of SLT mainly included steroids, alkaloids, flavonoids, terpenoids, anthraquinones, phenylpropanoids and others. Pharmacological action mainly contains anti-tumour, antibacterial, anti-inflammatory, anti-oxidation and other pharmacological actions, among them, the anti-tumour effect is particularly outstanding.

SUMMARY

At present, studies on the pharmacological effects of SLT mainly focus on alkaloids and steroidal saponins. In the follow-up studies, studies on the pharmacological activities of other chemical components in SLT, such as flavonoids and terpenoids, should be strengthened. It has the potential to pave the way for more research and development of novel SLT medicines.

Phytochemical and pharmacological studies on Solanum lyratum: a review

Solanum lyratum is one of the temperate plants, broadly distributed in Korea, China, Japan, India, and South-East Asia and well-documented in those oriental ethnic medicine systems for curing cancers, jaundice, edema, gonorrhea, cholecystitis, phlogosis, rheumatoid arthritis, etc. This review systematically summarized the research progress on S. lyratum respecting the botany, traditional uses, phytochemistry, pharmacology, and toxicology to increase people's in-depth understanding of this plant, by data retrieval in a series of online or off-line electronic databases as far as we can reach. Steroidal saponins and alkaloids, terpenoids, nitrogenous compounds, and flavonoid compounds are the main chemical constituents in S. lyratum. Among them, steroidal alkaloids and saponins are the major active ingredients ever found in S. lyratum, exerting activities of anti-cancer, anti-inflammation, anti-microbial, anti-allergy, and anti-oxidation in vivo or in vitro. As a result, S. lyratum has been frequently prescribed for the abovementioned therapeutic purposes, and there are substantial traditional and modern shreds of evidence of its use.

Pronounced anti-neuroinflammatory jasmonates and terpenes isolated from lychee seeds

Lychee is a favorite fruit of the Cantonese and native to Southeast Asia. In this study, the anti-neuroinflammatory bioactive compounds of lychee seeds have been carried out. Five new jasmonates (1, 2, 6-8) and seventeen known compounds were isolated using a series of chemical and chromatographic methods. Their chemical structures were identified through comprehensive spectroscopic analysis. Anti-neuroinflammatory activities were assayed and evaluated for the purified compounds. Most of the compounds exhibited pronounced anti-neuroinflammatory activities on nitric oxide (NO) induced by lipopolysaccharide (LPS) in BV-2 microglia cells. Moreover, compounds 1, 2 and 20 could reduce the expression of LPS-induced pro-inflammatory factors (iNOS and COX-2), inhibit the expression of mRNA levels of iNOS, COX-2, IL-6 and block NF-κB nuclear translocation in dose-dependent manners. This study suggested that lychee phytochemicals could be benefit to some neuroinflammatory-associated diseases, such as Alzheimer's disease.

Insecticidal and α-glucosidase inhibitory activities of chemical constituents from Viburnum fordiae Hance

The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C₁₃-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-β-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-β-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-β-ionyl 9-O-α-d-arabinopyranosyl-(1→6)-β-d-glucopyranoside (1) and 2-(4-O-β-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD₅₀ value of 140 μg g^-1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC₅₀ values ranging from 148.2 to 230.9 μM.

Terpenoids from the barks of Magnolia maudiae (Dunn) Figlar

A new germacrenolide (1) and fourteen known terpenoids (2-15) were isolated from the barks of Magnolia maudiae (Dunn) Figlar (Magnoliaceae). The structure of (7αH,11βH)-2α,8α-dihydroxy-4α,5β-epoxy-germacr-1(10)-en-6α,12-olide (1) was elucidated by physical and spectroscopic data analysis, including 1D, 2D NMR and HR-ESI-MS. Lyratol F (9) was isolated from Magnolia for the first time. The structures of known compounds were established by comparing their spectroscopic data with those in literatures.

Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species

The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species.

[Sesquiterpenoids from Solanum lyratum]

Ten compounds were isolated and purified by column chromatography over silica gel, preparative TLC, and Sephadex LH-20 from the whole plant of Solanum lyratum. The structures were elucidated on the basis of physico-chemical properties and spectral data as 1beta-hydroxy-1 ,2-dihydro-alpha-santonin (1) , boscialin (2) , blumenol C (3), 3beta-hydroxy-5alpha, 6alpha-epoxy-7-megastigmen-9-one(4), dehydrovomifoliol(5) , blumenol A(6), (1'S,2R,5S, 10R) -2-(1', 2'-dihydroxy-l1'-methylethyl) -6,10-dimethylspiro[4,5] dec-6-en-8-one(7) , (1'R,2R,5S,10R)-2-( 1',2'-dihydroxy-l '-methylethyl) -6,1 l0-dimethylspiro[4,5]dec-6-en-8-one( 8) , 2-(1',2'-dihydroxy-1 '-methylethyl) -6,1 0-dimethyl-9-hydroxyspiro [4,5] dec-6-en-8-one (9) , and grasshopper ketone (10). Compounds 1-10 were isolated from this plant for the first time.

New sesquiterpenoid derivatives from Solanum lyratum and their cytotoxicities

Three new sesquiterpenoid isopropylidene derivatives, named solajiangxins H and I (1 and 2) and 7-hydroxylsolajiangxin I (3), were isolated from the whole plant of Solanum lyratum. Their structures were elucidated on the basis of integrated spectroscopic techniques, mainly HR-FAB-MS, 1D NMR, and 2D NMR ((1)H-(1)H COSY, HMQC, HMBC, and NOESY). In vitro, compounds 1-3 were found to show significant cytotoxicity against three cancer cells (P-388, HONE-1, and HT-29), and gave IC50 values in the range of 3.2-7.7 μM.