Trisaccharides from Marsdenia roylei

Phenelfamycins G and H, new elfamycin-type antibiotics produced by Streptomyces albospinus Acta 3619

Phenelfamycins G and H are new members of the family of elfamycin antibiotics with the basic structure of phenelfamycins E and F, respectively, which are also well known as ganefromycins α and β. Phenelfamycins G and H differ from phenelfamycins E and F by an additional hydroxy group at position C-30, which is not described so far for any of the elfamycin-type antibiotics. The actinomycete strain that produced phenelfamycins G and H was identified to be Streptomyces albospinus based on its 16S rRNA gene sequence. Phenelfamycins G and H exhibit a narrow antibacterial spectrum with a pronounced inhibitory activity against Propionibacterium acnes.

A new pregnane glycoside from Marsdenia roylei as potential antioxidant and antidyslipidemic agents

A new pregnane glycoside roylenine (1) was isolated from the CHCl(3)-EtOH (4:1) extract of Marsdenia roylei. Its structure was established on the basis of spectroscopic studies. The glycoside (1) and its acetylated derivative (6) were evaluated for their antioxidant and antidyslipidemic activities.

A study of the larvicidal and molluscicidal activities of some medicinal plants from northeast Brazil

In a search for natural products that could be used to control the vectors of tropical diseases, 23 extracts of medicinal plants from the northeast of Brazil have been tested for molluscicidal activity against egg masses and adults of the snail Biomphalaria glabrata, for larvicidal activity against the larvae of the mosquito Aedes aegypti, and for general toxicity against the larvae of the brine shrimp Artemia salina. Of these extracts, two were active against the adult snail, one against snail egg masses, eight against the larvae of the mosquito, and 16 showed toxicity towards the brine shrimp. Chemical tests indicated that a wide variety of natural product classes were present in those extracts that showed significant activities in the bioassays.

Pregnanes and pregnane glycosides from Marsdenia roylei

Two pregnanes namely desacylkondurangogenin C (1) and deniagenin (3, new) and two new pregnane glycosides designated as denin (5) and marsin (12) have been isolated from chloroform soluble extract of dried stem of Marsdenia roylei. Chemical and spectroscopic evidences are consistent with the structures of deniagenin, denin and marsin as 3beta, 11alpha, l2beta, 14beta, 17beta, 20-hexahydroxy pregn-5-ene; desacylkondurangogenin C-3-O-alpha-D-glucopyranosyl-(1-->4)-O-alpha-L-fucopyranoside and ketocalogenin-3-O-alpha-L-fucopyranoside, respectively.