Diterpenoid Alkaloids from Consolida regalis S. F.Gray subsp.paniculata (Host) Soo var. paniculata.

Seven diterpenoid alkaloids : delcosine(1), delsoline(2), gigactonine(3), lycoctonine(4), takaosamine(5), atisine(6) and hetisinone(7) have been isolated from the aerial parts of Consolida regalis subsp. paniculata var. paniculata. The presence of compounds 1,2,5,6 and 7 in this plant has not been previously reported.

Effects of Crataegus microphylla on vascular dysfunction in streptozotocin-induced diabetic rats.

Vascular dysfunction plays a key role in the pathogenesis of diabetic vascular disease. In this study, we aimed to investigate whether chronic in vivo treatment of Crataegus microphylla (CM) extract in diabetic rats induced with streptozotocin (STZ, intraperitoneal, 65 mg/kg) preserves vascular function and to evaluate whether the reduction of inducible nitric oxide synthase (iNOS), proinflammatory cytokines, and lipid peroxidation mediates its mechanisms of action. Starting at 4 weeks of diabetes, CM extract (100 mg/kg) was administrated to diabetic rats for 4 weeks. In aortic rings, relaxation to acetylcholine and vasoreactivity to noradrenaline were impaired, whereas aortic iNOS expression and plasma tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), total nitrite-nitrate, and malondialdehite levels were increased in diabetic rats compared with controls. Chronic CM treatment significantly corrected all the above abnormalities in diabetic rats. In comparison, pretreatment of the aorta of diabetic rats with N-[3(aminomethyl) benzyl]-acetamidine, dihydrochloride (10(-5) M), a selective inhibitor of iNOS, produced a similar recovery in vascular reactivity. These results suggest that chronic in vivo treatment of CM preserves endothelium-dependent relaxation and vascular contraction in STZ-induced diabetes, possibly by reducing iNOS expression in the aorta and by decreasing plasma levels of TNF-α and IL-6 and by preventing lipid peroxidation.

Diterpenoid alkaloids of Aconitum vulparia Rchb.

From the roots of Aconitum vulparia Rchb., collected in Prüm (Germany), a new norditerpenoid alkaloid, named alexhumboldtine, has been isolated along with the known norditerpenoid alkaloids lappaconitine, anthranoyllycoctonine, lycoctonine, puberaconitine, ajacine, and septentriodine. The structure of alexhumboldtine was established on the basis of 1H, 13C, DEPT, homonuclear 1H COSY, NOESY, HSQC, and HMBC NMR studies. From the aerial parts of the plant another norditerpenoid alkaloid, aconorine, has been isolated.

Norditerpenoid alkaloids from Delphinium flexuosum Bieb.

Delphiniflexine, a new norditerpenoid alkaloid, together with the three known norditerpenoid alkaloids methyllycaconitine, ajadine, and acoseptrigenine were isolated from the aerial parts of Delphinium flexuosum. The structure of delphiniflexine was established on the basis of 1H, 13C, DEPT, homonuclear 1H COSY, NOESY, HSQC, and HMBC NMR studies.

Evaluation of Turkish seaweeds for antiprotozoal, antimycobacterial and cytotoxic activities.

As part of our continuing research on seaweeds, crude MeOH extracts of two green, three brown and six red algae collected from Marmara, Black, Aegean and Mediterranean Seas were screened. Four parasitic protozoa, i.e. Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms for the in vitro assays. The selective toxicity of the extracts was also determined against mammalian L6 cells. All seaweed extracts were active against T. brucei rhodesiense; the Dasya pedicellata extract was the most potent (IC(50) value 0.37 µg/mL). The same extract also weakly inhibited the growth of T. cruzi (IC(50) 62.02 µg/mL). All seaweed extracts also showed leishmanicidal activity (IC(50) values 16.76-69.98 µg/mL). The majority of the extracts also exhibited antiplasmodial potential and the most potent extracts were those from D. pedicellata (IC(50) 0.38 µg/mL), Codium bursa (IC(50) 1.38 µg/mL) and Caulerpa rasemosa (IC(50) 3.12 µg/mL). One brown and two red algal extracts showed some weak activity against Mycobacterium tuberculosis (MIC values 125-256 µg/mL). Except for the extract of Dasya pedicellata, none of the extracts displayed any cytotoxicity. This is the second study investigating the antiprotozoal activities of Turkish marine algae and identifies Dasya pedicellata, an understudied algal species, as a candidate for further studies.

Flavonoids of Helichrysum compactum and their antioxidant and antibacterial activity.

From the capitula of Helichrysum compactum, the flavonoids apigenin, kaempferol, luteolin, naringenin, 3,5-dihydroxy-6,7,8-trimethoxyflavone, kaempferol-3-O-glucoside, luteolin-7-O-glucoside and luteolin-4',7-di-O-glucoside and from the leafy stems apigenin, kaempferol, luteolin, quercetin, apigenin-7-O-glucoside, luteolin-7-O-glucoside, and quercetin-3-O-glucoside were isolated. Extracts of the capitula of H. compactum show antioxidant activity by inhibition of lipid peroxidation and also show antibacterial activity.

Flavonoids of Crataegus microphylla.

Crataegus microphylla C. Koch is one of the 17 species of Crataegus growing in Turkey [H.P.T. Ammon and R. Kaul (1994). Dtsch. Apoth. Ztg., 134, 2433, 2521, 2631.]. This report is part of a series on the chemical investigations of Crataegus species from Turkey. Nine flavonoids have been isolated from the leaves and flowers of C. microphylla C. Koch. The amounts of the flavonoids from the leaves and flowers of the plant were determined.