The first biological inclusion in Cretaceous (Cenomanian) amber from Texas (USA) is here documented. Most of the Cretaceous ambers with biological inclusions are from Europe (Spain, France) and Myanmar (Asia). Although the coleopteran here reported is microscopic and incomplete, it preserves enough morphological details to be identified as a member of the Family Ptinidae Latreille, 1802. This antecedent is significative and reveals the potential of this Cretaceous amber to contain more diverse bioinclusions, since the paleoenvironment suggested by the sediments that contain the amber and the ecological affinity of recent representatives of the Ptinidae suggest a humid forest near an estuary, associated to deltaic plain deposits. Este hallazgo representa la inclusión biológica en ámbar más antigua en las Americas.

The class of plant exudates that contain the phenol functionality, termed phenolics, is defined, surveyed, and characterized by solid-state 13C NMR spectroscopy and by solution-state 1H NMR spectroscopy. Materials in this group are identified by the phenolic 13C resonance (from the ipso carbon of ArOH) at δ 145-160 (δ 160-167 for ArOR). The resonance patterns define several subclasses based on the collective similarity of their 13C spectra, specifically, aloetics from the genus Aloe, guaiacs from the genus Guaiacum and other eurosid and conifer genera, xanthics from the genus Garcinia, and kinos from the genus Eucalyptus and many other genera. Phenolic exudates often are mixed with terpenoid materials (the building block of exudates known as resins) and carbohydrates (the building block of exudates known as gums) to form hybrid subgroups such as guaiac gums, guaiac resins, and kino resins. There are numerous phenolic exudates not affiliated with any of these groups, both as pure phenolics and as hybrids (phenolic resins, phenolic gum resins, and phenolic waxes).

Structural changes caused by heating of fossilized (amber) and semifossilized (copal) resins have been examined by nuclear magnetic resonance spectroscopy. A set of 28 samples was constituted to include different geographical sources, degrees of maturation, colors, and structural groupings. The onset of structural alterations was determined by observation of the lowest temperature at which spectral changes occurred. Both proton spectra in solution and carbon-13? spectra in the solid state then were recorded of cooled samples after heating for 12 hr at temperature increments, until liquification of the sample began. The spectra of both nuclides exhibit loss of a few peaks, broadening of most peaks, and enhancement of the unsaturated or aromatic region at the expense of saturated resonances. Such changes are irreversible and lead to a harder and less soluble material on cooling. The changes parallel those that occur with maturation of fossil resins or materials that lead to coal.

Roles for the element silicon (Si) in biochemical processes have been considered in both science fiction and real science. The hypothesis that Si could replace carbon (C) as the core element in so-called silicon-based life fails on a number of grounds, even though Si is just below C in the periodic table and has many similar bonding properties. First, bonds between two Si atoms or between Si and C are weaker than those between two carbon atoms, and bonds between Si and a host of common elements (hydrogen, carbon, halogens, and nitrogen) are chemically and photochemically reactive and subject to decomposition. Second, the chemistry of Si, in general, lacks molecules that contain unsaturation, in particular, double bonds (Si==C, Si==Si, Si==O, Si==N). Molecules containing the analogous unsaturated carbon molecules (C==C, C==O, C==N) are integral parts of almost all biomolecules, including amino acids, proteins, carbohydrates, nucleic acids, fatty acids, and vitamins. Devoid of unsaturated molecules, organosilicon systems could not serve as building blocks for the complex chemistry necessary for life. However, because of the high strength and stability of the Si—O bond, as in silicates, such systems can participate in the biochemistry of carbon-based systems. Silica can be taken up and incorporated into the structure of numerous plant and animal organisms. Silicates can be chiral and possibly serve in the process of chiral resolution of carbon molecules. Silicates can select and sequester unstable carbohydrates in their synthesis via the formose reaction. Thus, Si can participate in life processes but cannot serve as the central element.

Assignments of the chemical shifts of the 7‐syn and 7‐anti protons in 2‐norbornene and of the methyl groups in α‐pinene and β‐pinene have been determined by means of nuclear Overhauser effects. These results constrain competing theories of the shielding effects of double bonds.

Amber is reported from a new locality in North Central Texas, USA.The amber clasts were found in thin carbonaceous horizons in the Woodbine Group.They exhibit a variety of colors including yellow, orange, red, brown and opaque white.No zooinclusions have been found, but some clasts present plant debris and inorganic inclusions. 13C NMR, 1 H NMR, FTIR, and GC/MS analyses assign this amber to Group A or Class 1b and, as such, the botanical origin is considered to be a conifer.The low diversity palynomorph assemblage of the sediments is suggestive of a nearby source.The paleoenvironment is interpreted as non-marine, fluvial deltaic.Abundant charcoal fragments are noted.This observation is in concordance with the description of the Cretaceous period being a time of fires.Based on stratigraphic and palynologic data, the age of the amber is Early Cenomanian.This research represents the first study of amber in Texas.

A number of blocks of resinous materials were found in the cargo of a 12th- to 13th-century shipwreck, discovered in the late 1980s in the Java Sea near the Indonesian islands of Sumatra and Java and excavated in 1996. These well-preserved blocks presumably were trade materials used for religious, medicinal, cosmetic, decorative or practical purposes. Such materials, derived from plants and termed exudates, generally include frankincense, myrrh, ‘gum benjamin’, liquidambar, dragon's blood, dammar, copal and amber. The source of the cargo resin could not be determined from the site. Investigation by nuclear magnetic resonance (NMR) spectroscopy has revealed that the molecular structure corresponds to that of modern resin from the plant family Dipterocarpaceae, known in trade as dammar and closely resembling Group B copal and amber. Other molecular classes of exudates are excluded. Such materials are not present in the Middle East, which then cannot be their source. The NMR spectra differ from those of Group B samples from Australia, Papua New Guinea and Indonesia, but resemble those from India or Japan. The spectra indicate that the saline environment had a similar effect on the molecular structure to heating and aging.