A new steroidal glycoside from the seeds of Hyoscyamus niger
A new steroidal glycoside hyoscyamoside G (1), together with two known analogues hyoscyamoside E (2) and hyoscyamoside F1 (3), was isolated from the seeds of Hyoscyamus niger. The structure of 1 was established as (22R,24Z)-1α,3β,7β,22,26-pentakishydroxylergost-22-O-β-d-gulcopyranosyl-5,24-diene-26-O-β-d-glucopyranoside, by means of chemical and spectroscopic methods including HRESI-MS, 1D and 2D NMR. In vitro, compound 2 showed cytotoxicity against human lung cancer cell H460 with IC50 value of 66 μg/mL.
Hyoscyamus niger L. (Solanaceae)
A biennial or annual herb found in Asia, northwest China, Europe, and North Africa. Its name is derived from the Anglo-Saxon Hen (chicken) and Bana (murderer), because when fowls eat the seeds of this plant, they become paralyzed and die. All parts of the plant are poisonous, even small amounts cause from dizziness to delirium along with other anticholinergic effects. Seeds are also poisonous to children, rodents, pigs, and fish. Three kinds were known to the Greeks: black, white and yellow. Pliny mentioned four kinds, first with black seeds (H. reticulatus), the second with brownish-gray seeds (H. niger), the third with reddish seeds (H. aureus), and the fourth with white seeds (H. albus), which is medicinally preferred. The white variety was also the only one recommended by Dioscorides and Galen. Henbane is described as intoxicating, narcotic and anodyne. Its uses include a poultice made of leaf juice with barley flour to relieve pain of inflammatory swellings. Seeds increase blood clotting, and are used in a dose of 15 mg in bleeding conditions. Ibn Jazlah did not recommend its use due to its toxicity, and Razi called it Saykarān al-Dūr, which indicates in Arabic a person who is drunk. It is one of the four plants that are used in Ayurveda for the treatment of Parkinson’s disease. It has peculiarly sedative effect beneficial in irritable affections of the lungs, bowels, and genitourinary tract, such as cystitis. Leaves contain about 0.04% alkaloids (mainly hyoscyamine and scopolamine), the glycoside hyoscypicrin, and choline. Withanolide class steroids, lignanamides, rutin, hyoscyamide, β-sitosterol, daucosterol, coumarinolignans, tetrahydrofuranolignan, and steroidal glycosides, have been isolated from seeds. Methanol seed extract produced significant analgesic, anti-inflammatory and antipyretic activities; cleomiscosin A is suggested to play a role in anti-inflammatory effect. Methanol seed extract also exhibited anticonvulsant activity against picrotoxin-induced seizures in mice.
Effects of glycoalkaloids from Solanum plants on cucumber root growth.
The phytotoxic effect of four glycoalkaloids and two 6-O-sulfated glycoalkaloid derivatives were evaluated by testing their inhibition of cucumber root growth. The bioassays were performed using both compounds singly and in equimolar mixtures, respectively. Cucumber root growth was reduced by chaconine (C), solanine (S), solamargine (SM) and solasonine (SS) with IC(50) values of 260 (C), 380 (S), 530 (SM), and 610 microM (SS). The inhibitory effect was concentration-dependent. 6-O-sulfated chaconine and 6-O-sulfated solamargine had no inhibitory effects, which indicated that the carbohydrate moieties play an important role in inhibiting cucumber root growth. The equimolar mixtures of paired glycoalkaloids, both chaconine/solanine and solamargine/solasonine, produced synergistic effects on inhibition of cucumber root growth. By contrast, mixtures of unpaired glycoalkaloids from different plants had no obviously synergistic effects. The growth inhibited plant roots lacked hairs, which implied that inhibition was perhaps at the level of root hair growth.