New C9 -Monoterpenoid Alkaloids Featuring a Rare Skeleton with Anti-Inflammatory and Antiviral Activities from Forsythia suspensa

Forsyqinlingines C (1) and D (2), two C₉ -monoterpenoid alkaloids bearing a rare skeleton, were isolated from the ripe fruits of Forsythia suspensa. Their structures, including absolute configurations, were fully elucidated by extensive spectroscopic data and ECD experiments. The plausible biogenetic pathway for compounds 1 and 2 was also proposed. In vitro, two C₉ -monoterpenoid alkaloids showed anti-inflammatory activity performed by the inhibitory effect on the release of β-glucuronidase in rat polymorphonuclear leukocytes (PMNs), as well as antiviral activity against influenza A (H1N1) virus and respiratory syncytial virus (RSV).

Trinorlabdane diterpenoid alkaloids featuring an unprecedented skeleton with anti-inflammatory and anti-viral activities from Forsythia suspensa

Two unique trinorlabdane diterpenoid alkaloids, forsyqinlingines A (1) and B (2), were isolated from the ripe fruits of Forsythia suspensa. Their structures, including absolute stereochemical configurations, were fully elucidated from extensive spectroscopy experiments, single-crystal X-ray diffraction, and electronic circular dichroism (ECD). In addition, a plausible biosynthetic pathway for the formation of compounds 1 and 2 in Forsythia suspensa was also proposed. In vitro, the two C₁₇-labdane diterpenoid alkaloids exhibited anti-inflammatory activities by inhibiting the release of β-glucuronidase in rat polymorphonuclear leukocytes (PMNs), and antiviral activities against influenza A (H1N1) virus and respiratory syncytial virus (RSV).

Two unique trinorlabdane diterpenoid alkaloids, forsyqinlingines A (1) and B (2), were isolated from the ripe fruits of Forsythia suspensa, and found to show significant anti-inflammatory activities and anti-viral activities.

Alkaloids bearing rare skeletons from Forsythia suspensa with anti-inflammatory and anti-viral activities in vitro

Five alkaloids, including two previously undescribed alkaloids, named forsyshiyanines A and B, attributable to the rare skeletons 4b,5,6,7,8,8a,9,10-octahydrobenzo[f]quinoline and (6,7-dihydro-5H-cyclopenta[c]pyridin-7-yl)methyl, respectively, along with three known ones (3-5), were isolated from the ripe fruits of Forsythia suspensa. The chemical structures including absolute configurations of two undescribed compounds were established using integrated spectroscopic techniques, electronic circular dichroism calculations, and single-crystal x-ray diffraction analysis. In vitro, five alkaloids showed anti-inflammatory activities, with the inhibition rates of the release of β-glucuronidase from polymorphonuclear leukocytes of rats being in the range 47.9%-56.0% at a concentration of 10 μM. Moreover, five compounds exhibited anti-viral activities against influenza A virus and respiratory syncytial virus, with IC₅₀ values in the range of 7.3-32.5 μM and EC₅₀ values in the range 3.7-14.1 μM.

[Diterpenoids from Scutellaria strigillosa]

By means of preparative HPTLC and column chromatography over silica gel and Sephadex LH-20, nine diterpenoids were isolated and purified from the whole plants of Scutellaria strigillosa. Based on the physico-chemical properties and spectral data, their structures were elucidated as: 6-O-acetyl-7-O-nicotinoylscutebarbatine G(1), 6-O-nicotinoyl-7-O-acetylscutebarbatine G(2), 6,7-di-O-nicotinoylscutebarbatine G(3), scutebarbatine K(4), scutebarbatine B(5), 6-O-acetylscutehenanine A(6), 6-O-nicotinoylbarba- tin A(7), 6,7-di-O-acetoxylbarbatin A(8), scutebarbatine F(9). Compound 1 is a new diterpenoid, and compounds 2-9 were isolated from Scutellaria strigillosa for the first time.

[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.

Two new C13-norisoprenoids from Solanum lyratum

Two new C(13)-norisoprenoids, named lyratols E and F (1-2), were isolated from the whole plant of Solanum lyratum Thunb, and their structures were elucidated by extensive spectroscopic analyses. In vitro, two new compounds were found to show significant cytotoxicity against selected cancer cells including P-388 and HT-29.

Two new cytotoxic ent-clerodane diterpenoids from Scutellaria barbata

Two new ent-clerodane diterpenoids have been isolated from Scutellaria barbata, and their structures were established by detailed spectroscopic analyses as (13R)-6α,7β-dihydroxy-8β,13-epoxy-11β-nicotinyloxy-ent-clerodan-3-en-15,16-olide (scutelinquanine D, 1) and (11E)-6α-acetoxy-7β,8β-dihydroxy-ent-clerodan-3,11,13-trien-15,16-olide (6-acetoxybarbatin C, 2). In vitro, the isolated two new compounds showed significant cytotoxic activities against three human cancer cell lines (HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells), and gave IC(50) values in the range of 2.5-6.6 μM.

Effect of astilbin on experimental diabetic nephropathy in vivo and in vitro

Astilbin, a flavonoid compound, was isolated from the rhizome of Smilax glabra Roxb. This study was conducted to investigate the efficacy of astilbin on experimental diabetic nephropathy (DN) in vivo and in vitro and its possible mechanisms. Astilbin was added in high glucose stimulated HK-2 cells, streptozotocin-induced experimental DN, randomized to receive intragastric ( I. G.) astilbin to observe its anti-renal lesion effect. Results showed that astilbin inhibited high glucose stimulated HK-2 cell production of transforming growth factor-beta1 (TGF-beta1) and connective tissue growth factor (CTGF) in vitro, especially CTGF; analogic results was also found in vivo. I. G. of astilbin 2.5 mg/kg or 5 mg/kg significantly ameliorated renal function, reduced kidney index, while it increased body weight and survival time in animals. In addition there was no significant difference in blood glucose level between the STZ-treated group and the astilbin groups. Furthermore, astilbin ameliorated the pathological progress of renal morphology. Astilbin can exert an early renal protective role to DN, inhibit production of TGF-beta1 and especially of CTGF. We suggest that astilbin inhibition of CTGF may be a potential target in DN therapy. This work provides the first evidence for astilbin as a new candidate of DN therapeutic medicine.