Analogues of the antibiotic thiolactomycin (TLM) have been synthesized and have been shown to have enhanced activity against whole cells of Mycobacterium tuberculosis H37Rv and against mycolic acid biosynthesis in cell extracts of Mycobacterium smegmatis. TLM has a methyl-branched butadienyl side chain attached at position 5 on a ‘thiolactone’ ring, namely 4-hydroxy-3,5-dimethyl-5H-thiophen-2-one. Various combinations of strong bases were explored to create a reactive anion at position 5 on the thiolactone ring which could react with halides to produce 5-substituted derivatives; the best reagent was two equivalents of lithium-bis-(trimethylsilyl)amide in tetrahydrofuran. The analogue with a 5-tetrahydrogeranyl substituent showed the best biological activity with an MIC90 for M. tuberculosis of 29 μM and 92% mycolate inhibition in extracts of M. smegmatis, as compared to 125 μM and 54%, respectively, for TLM; other related C10 and C15 isoprenoid derivatives had similar biological activity. These isoprenoid-based derivatives did not inhibit type II fatty acid synthase from M. smegmatis, but compounds with iso-butyl and iso-butenyl side chains did show some inhibitory activity against this enzyme. These short-chain derivatives did not inhibit mycolate synthesis or have significant antibiotic activity. Treatment of the thiolactone with a weaker base, sodium hydride in tetrahydrofuran, gave 3-alkyl-3,5-dimethyl-thiophene-2,4-dione analogues, which had no effect on fatty acid or mycolate synthesis. However, the geranyl derivative had an MIC99 of 60 μM for M. tuberculosis, one quarter that (240 μM) of TLM, demonstrating its excellent antibiotic potential against an unknown cellular target.

Mycobacterium tuberculosis has a cell envelope incorporating a peptidoglycan-linked arabinogalactan esterified by long-chain mycolic acids. A range of "free" lipids are associated with the "bound" mycolic acids, producing an effective envelope outer membrane. The distribution of these lipids is discontinuous among mycobacteria and such lipids have proven potential for biomarker use in tracing the evolution of tuberculosis. A plausible evolutionary scenario involves progression from an environmental organism, such as Mycobacterium kansasii, through intermediate "smooth" tubercle bacilli, labelled "Mycobacterium canettii"; cell envelope lipid composition possibly correlates with such a progression. M. kansasii and "M. canettii" have characteristic lipooligosaccharides, associated with motility and biofilms, and glycosyl phenolphthiocerol dimycocerosates ("phenolic glycolipids"). Both these lipid classes are absent in modern M. tuberculosis sensu stricto, though simplified phenolic glycolipids remain in certain current biotypes. Dimycocerosates of the phthiocerol family are restricted to smaller phthiodiolone diesters in M. kansasii. Diacyl and pentaacyl trehaloses are present in "M. canettii" and M. tuberculosis, accompanied in the latter by related sulfated acyl trehaloses. In comparison with environmental mycobacteria, subtle modifications in mycolic acid structures in "M. canettii" and M. tuberculosis are notable. The probability of essential tuberculosis evolution taking place in Pleistocene megafauna, rather than Homo sapiens, is reemphasised.

This study derives from the macroscopic analysis of a Late Neolithic population from Hungary. Remains were recovered from a tell settlement at Hódmezővásárhely-Gorzsa from graves within the settlement as well as pits, ditches, houses and as stray finds. One of the most important discoveries from these remains was evidence of tuberculosis. Pathological analysis of the seventy-one individuals revealed numerous cases of infections and non-specific stress indicators on juveniles and adults, metabolic diseases on juveniles, and evidence of trauma and mechanical changes on adults. Several cases showed potential signs of tuberculosis and further analyses were undertaken, including biomolecular studies. The five individuals were all very young adults and included a striking case of Hypertrophic Pulmonary Osteopathy (HPO) with rib changes, one case with resorptive lesions on the vertebrae, two cases with hypervascularisation on the vertebrae and periosteal remodelling on the ribs, and one case with abnormal blood vessel impressions and a possible lesion on the endocranial surface of the skull. The initial macroscopic diagnosis of these five cases was confirmed by lipid biomarker analyses, and three of them were corroborated by DNA analysis. At present, these 7000-year-old individuals are among the oldest palaeopathological and palaeomicrobiological cases of tuberculosis worldwide.

Many tuberculosis and leprosy infections are latent or paucibacillary, suggesting a long time-scale for host and pathogen co-existence. Palaeopathology enables recognition of archaeological cases and PCR detects pathogen ancient DNA (aDNA). Mycobacterium tuberculosis and Mycobacterium leprae cell wall lipids are more stable than aDNA and restrict permeability, thereby possibly aiding long-term persistence of pathogen aDNA. Amplification of aDNA, using specific PCR primers designed for short fragments and linked to fluorescent probes, gives good results, especially when designed to target multi-copy loci. Such studies have confirmed tuberculosis and leprosy, including co-infections. Many tuberculosis cases have non-specific or no visible skeletal pathology, consistent with the natural history of this disease. M. tuberculosis and M. leprae are obligate parasites, closely associated with their human host following recent clonal distribution. Therefore genotyping based on single nucleotide polymorphisms (SNPs) can indicate their origins, spread and phylogeny. Knowledge of extant genetic lineages at particular times in past human populations can be obtained from well-preserved specimens where molecular typing is possible, using deletion analysis, microsatellite analysis and whole genome sequencing. Such studies have identified non-bovine tuberculosis from a Pleistocene bison from 17,500 years BP, human tuberculosis from 9000 years ago and leprosy from over 2000 years ago.