ABSTRACT
Luo Han Guo (LHG) fruits (Siraitia grosvenorii Swingle) have been used as traditional medicine in China for centuries to treat sore throats and coughs. However, LHG leaves are seldom used and minimal scientific information is available on them. In our recent study on the leaves of S. grosvenorii, the bioactive compounds ß-amyrin (2), aloe emodin (5), aloe-emodin acetate (6), 5α,8α-epidioxy-24(R)-methylcholesta-6,22-dien-3ß-ol (7) and p-hydroxyl benzyl acid (8), accompanied by n-hexadecaoic acid (1), 12-methyltetradecanoic acid (3), ß-sitosterol (4) and daucosterol (9) were first obtained. Their structures have been identified on the basis of spectroscopic studies. The activities of these compounds were evaluated in vitro against the growth of oral bacterial species Streptococcus mutans, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum and the yeast Candida albicans, and their minimum inhibition concentrations were determined. Furthermore, the activity against S. mutans is likely to be due to the inhibition of glucosyltransferase. The experimental data provide important information on bioactive phytochemicals in the leaf of S. grosvenorii, which shows that the leaf can be a new resource as an antibacterial agent.
Subject(s)
Anthraquinones/isolation & purification , Anthraquinones/pharmacology , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Cucurbitaceae/chemistry , Drugs, Chinese Herbal/isolation & purification , Drugs, Chinese Herbal/pharmacology , Glucosyltransferases/antagonists & inhibitors , Hydroxybenzoates/isolation & purification , Hydroxybenzoates/pharmacology , Oleanolic Acid/analogs & derivatives , Aggregatibacter actinomycetemcomitans/drug effects , Anthraquinones/chemistry , Anti-Bacterial Agents/chemistry , Candida albicans/drug effects , Drugs, Chinese Herbal/chemistry , Fusobacterium nucleatum/drug effects , Hydroxybenzoates/chemistry , Microbial Sensitivity Tests , Molecular Structure , Oleanolic Acid/chemistry , Oleanolic Acid/isolation & purification , Oleanolic Acid/pharmacology , Plant Leaves/chemistry , Seeds/chemistry , Streptococcus mutans/drug effectsABSTRACT
Luo Han Kuo fruit (Siraitia grosvenori Swingle) has been used in China for centuries as a sweetening agent, and also used to treat sore throat and cough. In our recent study, a new bioactive compound, (2R,3S,4S)-2,3-trans-3,4-cis-5,3'-bimethoxy-7-(trans-2-propenal)-3,4-flavandiol (1), named siraitiflavandiol was obtained. The structure has been determined on the basis of spectroscopic studies including 1D and 2D NMR ((1)H, (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC, and NOESY), CD, EI-MS, and HR-EI-MS spectra. The new compound was evaluated in vitro for its inhibitory ability against the growth of oral bacterial species Streptococcus mutans, Porphyromonas gingivalis, and yeast Candida albicans. The minimum inhibitory concentrations were 6, 24, and 6 microg/ml, respectively.
