Morphological observations on Absidia corymbifera and Absidia blakesleeana strains preserved under mineral oil
Macro‐ and micromorphology of 30 living subcultures of Absidia corymbifera (10 strains plus three strains of Absidia ramosa) and Absidia blakesleeana (two strains) preserved under mineral oil at room temperature for periods ranging from 3 to 44 years in The Fungal Culture Collection of Instituto Oswaldo Cruz (IOC) were observed and described by permanent mycological preparations mounted in a glycerol 10% and/or Amann lactophenol solution. Vegetative and asexual reproductive structures are illustrated by drawings made with the aid of a camera‐lucida. The study showed that the period of maintenance under mineral oil and the stress which took place during the period of storage did not affect the vegetative and asexual reproductive morphology of the Absidia strains and species studied here.
Sexual reproduction in subcultures of Absidia blakesleeana after years of preservation under mineral oil.
Two subcultures of Absidia blakesleeana IOC No. 2425 (-) mating type strain preserved in 1959 and 1981 on a thick layer of potato dextrose agar (PDA) medium under sterile mineral oil and maintained at room temperature in the Fungal Cultural Collection of Institute Oswaldo Cruz--IOC--were paired with the defined Absidia blakesleeana URM-UFP No. 2076 (+) mating type strain. Portions of the line where mycelia of the two strains met were observed under light microscopy. Zygospores belonging to Subgenus Mycocladus were observed. The results demonstrated conservation and re-establishment of the physiological and genetic metabolic processes of two subcultures preserved under mineral oil.
New Sweet-Tasting C21-Pregnane Glycosides from Pericarps of Myriopteron extensum.
Ten novel C21 pregnane glycosides, extensumside C-L (1-10), were isolated as highly sweet-tasting substances from the edible pericarps of Myriopteron extensum (Wight) K. Schum by sensory-guided fractionation and purification. Their structures were determined through 1D and 2D NMR, such as HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY, and ROESY, as well as other spectroscopic analysis combined with chemical evidence. These compounds shared the same aglycone, 3β,16α-dihydroxy-pregn-5-en-20-one, and contained the deoxysugar chain and the glucose chain which were linked to C-3 and C-16 of the aglycone, respectively. The sweetness potency was evaluated by a human sensory panel test and preliminary structure-taste relationship was discussed. The sweetness intensities of these compounds are between 50 and 400 times greater than that of sucrose. Furthermore, quantitation analyses of compounds 1, 3, 4, and 6 in different parts of M. extensum indicated that the concentrations of these sweet components in the pericarps are obviously higher than those in stems and roots.