  We aim to characterize the physical and chemical properties of fragmented
cores during the earliest evolutionary stages in the very young star-forming
regions ISOSS J22478+6357 and ISOSS J23053+5953. NOEMA 1.3 mm data are used in
combination with archival mid- and far-infrared observations to construct and
fit the SEDs of individual fragmented cores. The radial density profiles are
inferred from the 1.3 mm continuum visibility profiles and the radial
temperature profiles are estimated from H2CO rotation temperature maps.
Molecular column densities are derived with the line fitting tool XCLASS. The
physical and chemical properties are combined by applying the physical-chemical
model MUSCLE in order to constrain the chemical timescales of a few line-rich
cores. The morphology and spatial correlations of the molecular emission are
analyzed using the HOG method. The mid-infrared data show that both regions
contain a cluster of young stellar objects. Bipolar molecular outflows are
observed in the CO 2-1 transition toward the strong mm cores indicating
protostellar activity. We find strong molecular emission of SO, SiO, H2CO, and
CH3OH in locations which are not associated with the mm cores. These shocked
knots can be either associated with the bipolar outflows or, in the case of
ISOSS J23053+5953, with a colliding flow that creates a large shocked region
between the mm cores. The mean chemical timescale of the cores is lower (20 000
yr) compared to that of the sources of the more evolved CORE sample (60 000
yr). With the HOG method, we find that the spatial emission of species tracing
the extended emission and of shock-tracing molecules are well correlated within
transitions of these groups.
