Isoflavone glycosides from Derris scandens

Five isoflavone glycosides, named derriscandenosides A–E (1–5), were isolated from the stems of Derris scandens, together with ten known compounds comprising one isoflavone, two benzoic acid derivatives, three glucosyl isoflavones and four rhamnosyl-(1→6)-glucosyl isoflavones. The structures of the glycosides were assigned on the basis of spectroscopic data, especially of the acetate derivatives. Three known rhamnosyl-(1→6)-glucosyl isoflavones isolated from a crude fraction were retested for hypotensive activity with varying results.     

Airborne fungal spore distribution in Bangkok,Thailand: correlation with meteorological variables and sensitization in allergic rhinitis patients

Information about airborne fungal spore is crucial for health risk assessment and management, especially for patients with allergy and asthma. Nonetheless, such data are rarely available from certain areas of the world, including Southeast Asia. The aim of this study was to gain updated information about airborne fungal spore in Bangkok, the capital city of Thailand. A survey was conducted at five sampling sites in Bangkok, using the Rotorod Sampler^® for a period of 1 year. High concentrations of spores were found all year with the peak between August and November. The most prominent spore types were Cladosporium, Nigrospora, Puccinia, Aspergillus/Penicillium, and Fusarium. The spore concentrations were positively and significantly correlated with the amount of rainfall and relative humidity, reaching the maximum level in September. Sensitization rates to Cladosporium, Penicillium, and Aspergillus among Thai atopic patients were approximately 16.6, 13.6, and 13.0%, respectively.     

Isoflavone glycosides from Derris scandens

Five isoflavone glycosides, named derriscandenosides A–E (1–5), were isolated from the stems of Derris scandens, together with ten known compounds comprising one isoflavone, two benzoic acid derivatives, three glucosyl isoflavones and four rhamnosyl-(1→6)-glucosyl isoflavones. The structures of the glycosides were assigned on the basis of spectroscopic data, especially of the acetate derivatives. Three known rhamnosyl-(1→6)-glucosyl isoflavones isolated from a crude fraction were retested for hypotensive activity with varying results.     

Somatic embryogenesis in Citrus SPP.: Carbohydrate stimulation and histodifferentiation

Summary Somatic embryogenesis from nucellus-derived callus cultures of five cultivars, including three (Caipira, Seleta Vermelha, and Valencia) of sweet oranges (C. sinesis L. Osbeck), Rangpur lime (C. limonia L. Osbeck), and Cleopatra mandarin (C. reticulata Blanco) (lines I and II), were studied. Callus lines maintained on MT medium supplemented with 50 g l⁻¹ sucrose were transferred to MT medium supplemented with different carbohydrate sources: galactose, glucose, lactose, maltose, or sucrose at 18, 37, 75, 110, or 150 mM, or glycerol at 6, 12, 24, 36, or 50 mM. Globular embryos were observed after approximately 4 wk, in several treatments. Cultures of Valencia and Caipira sweet oranges and Cleopatra mandarin (line I) showed high numbers of embryos on medium containing galactose, lactose, and maltose. Histological studies showed somatic embryos in all developmental stages with a normal histodiffeentiation pattern. The other two cultivars (Rangpur lime and Cleopatra mandarin, line II) formed very few embryos, which did not develop further following the globular stage. Some of the abnormalities observed were lack or dedifferentiation of protoderm and absence of apical meristems and procambial strands. Embryos that followed the normal sequence of development were easily converted into plants. Non-embryogenic cultures continued as proliferating callus cultures, eventually forming a few embryos which did not convert into plants. Statistical analyses of the callus response to carbohydrate treatments was done using an overdispersion Poisson model.     

A benzil and isoflavone derivatives from Derris scandens Benth

A benzil derivative: scandione, 2',2"-dihydroxy-4'-methoxy-4",5"-methylenedioxybenzil and two isoflavones: scandenal, 3'-formyl-4',5-dihydroxy-2",2"-dimethylchromeno-[6,7:5",6"]isoflavone and scanderone, 4',5-dihydroxy-3'-prenyl-2",2"-dimethylchromeno-[7,8:6",5"]isoflavone together with fifteen known compounds were isolated from the stem of D. scandens. Their structures were determined by spectroscopic methods. Radical scavenging, antibacterial and hypertensive activities of some of the compounds were investigated.